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<h1>name:{name} job:{job} life:{life} .format(name='walterlife', job='JAVA Backend Engineer', life='work hard and have fun')</h1>
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<h3 class="title">
<div class="date"> Dec 3 2015 </div>
<div class="article-title"><a href="/2015/12/03/python-mysqldb-execute-use/" >python mysqldb insert时数据带有转义字符处理</a></div>
</h3>
<div class="entry">
<div class="row">
<div class="col-md-12">
<p>今天在使用python编写数据处理的时候，碰到数据中带有转义字符的时候，插入数据错误(数据是通过format拼接的，因此从数据库读取的字符串中的转移字符不能处理)</p>
<p>后来查阅资料,MysqlDB中的execute 可以将数据参数绑定到sql参数列表中(其实之前封装好的mysqlor.py中有该接口实现，只是从来没用过。。。今天才发现该接口的用处)</p>
<p>具体方法如下</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">params = [<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>]</span><br><span class="line">insert_sql = <span class="string">'INSERT INTO {tb} VALUES(%s, %s, %s)'</span>.format(tb=table_name)</span><br><span class="line">mysql_execute(cur, insert_sql, params) <span class="comment"># params为user对应的字段</span></span><br></pre></td></tr></table></figure>
<p>其中 mysql_execute 函数实现如下</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">def</span> <span class="title">mysql_execute</span><span class="params">(cursor, sql, param=None, debug=False)</span>:</span></span><br><span class="line"> <span class="string">u'''</span><br><span class="line"> 执行 SQL 语句</span><br><span class="line"> '''</span></span><br><span class="line"> <span class="keyword">if</span> cursor:</span><br><span class="line"> <span class="keyword">try</span>:</span><br><span class="line"> <span class="keyword">if</span> param <span class="keyword">in</span> [<span class="keyword">None</span>, <span class="string">""</span>, <span class="string">''</span>]:</span><br><span class="line"> <span class="keyword">return</span> cursor.execute(sql)</span><br><span class="line"> <span class="keyword">else</span>:</span><br><span class="line"> <span class="keyword">if</span> isinstance(param, (list, tuple)): param = param</span><br><span class="line"> <span class="keyword">if</span> debug: <span class="keyword">print</span> <span class="string">"cursor.execute(sql, param) parameter, sql: {s}, param: {p}"</span>.format(s=sql, p=param)</span><br><span class="line"> <span class="keyword">return</span> cursor.execute(sql, param)</span><br><span class="line"> <span class="keyword">except</span> IndexError:</span><br><span class="line"> <span class="comment">#except:</span></span><br><span class="line"> <span class="keyword">if</span> debug: <span class="keyword">print</span> <span class="string">"cursor.execute(sql, param) error, sql: {s}, param: {p}"</span>.format(s=sql, p=param)</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">None</span></span><br><span class="line"> <span class="keyword">else</span>:</span><br><span class="line"> <span class="keyword">if</span> debug: <span class="keyword">print</span> <span class="string">"mysql_execute parameter cursor is error."</span></span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">None</span></span><br></pre></td></tr></table></figure>
</div>
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<a type="button" href="/2015/12/03/python-mysqldb-execute-use/#more" class="btn btn-default more">阅读此文</a>
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<!-- display as entry -->
<h3 class="title">
<div class="date"> Oct 21 2015 </div>
<div class="article-title"><a href="/2015/10/21/maven-use-summary/" >maven_use_summary</a></div>
</h3>
<div class="entry">
<div class="row">
<div class="col-md-12">
<h3 id="1-_指定环境进行编译">1. 指定环境进行编译</h3><ul>
<li>在pom.xml 中定义各种 profile </li>
<li><p>在编译的时候指定 -Pprofile_id 即可</p>
<figure class="highlight xml"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="tag"><<span class="title">profiles</span>></span></span><br><span class="line"> <span class="tag"><<span class="title">profile</span>></span></span><br><span class="line"> <span class="tag"><<span class="title">id</span>></span>dd<span class="tag"></<span class="title">id</span>></span></span><br><span class="line"> ...</span><br><span class="line"> <span class="tag"></<span class="title">profile</span>></span></span><br><span class="line"><span class="tag"></<span class="title">profiles</span>></span></span><br></pre></td></tr></table></figure>
</li>
<li><p>可用于编译开发，测试，发布不同的版本</p>
</li>
</ul>
<h3 id="2-_去除测试">2. 去除测试</h3><ul>
<li>-Dmaven.test.skip = true 即可</li>
</ul>
<h3 id="3-_指定特定的测试模块进行测试">3. 指定特定的测试模块进行测试</h3><ul>
<li>-Dtest=test_unit_name 即可</li>
</ul>
</div>
</div>
<a type="button" href="/2015/10/21/maven-use-summary/#more" class="btn btn-default more">阅读此文</a>
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<!-- display as entry -->
<h3 class="title">
<div class="date"> Sep 13 2015 </div>
<div class="article-title"><a href="/2015/09/13/netty-server-learn/" >菜鸟学习系列--netty服务器启动流程分析</a></div>
</h3>
<div class="entry">
<div class="row">
<div class="col-md-12">
<p>最近在学习netty网络编程，下面以netty 中 DiscardServer 例子分析其流程</p>
<p>先贴下DiscardServer.java 代码<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">DiscardServer</span> </span>{</span><br><span class="line"> <span class="keyword">private</span> <span class="keyword">int</span> port;</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="title">DiscardServer</span><span class="params">(<span class="keyword">int</span> port)</span> </span>{</span><br><span class="line"> <span class="keyword">this</span>.port = port;</span><br><span class="line"> } </span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">run</span><span class="params">()</span> <span class="keyword">throws</span> InterruptedException </span>{</span><br><span class="line"> EventLoopGroup bossGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line"> EventLoopGroup workerGroup = <span class="keyword">new</span> NioEventLoopGroup();</span><br><span class="line"> <span class="keyword">try</span> {</span><br><span class="line"> ServerBootstrap b = <span class="keyword">new</span> ServerBootstrap(); <span class="comment">// 1</span></span><br><span class="line"> b.group(bossGroup, workerGroup) <span class="comment">// 2</span></span><br><span class="line"> .channel(NioServerSocketChannel.class) <span class="comment">// 3</span></span><br><span class="line"> .childHandler(<span class="keyword">new</span> ChannelInitializer<SocketChannel>() { <span class="comment">// 4</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> </span>{</span><br><span class="line"> ch.pipeline().addLast(<span class="keyword">new</span> DiscardServerHandler());</span><br><span class="line"> }</span><br><span class="line"> })</span><br><span class="line"> .option(ChannelOption.SO_BACKLOG, <span class="number">128</span>) <span class="comment">// 5</span></span><br><span class="line"> .childOption(ChannelOption.SO_KEEPALIVE, <span class="keyword">true</span>); <span class="comment">// 6</span></span><br><span class="line"> ChannelFuture f = b.bind(port).sync(); <span class="comment">// 7 bind 8 sync</span></span><br><span class="line"></span><br><span class="line"> f.channel().closeFuture().sync(); <span class="comment">// 9</span></span><br><span class="line"> } <span class="keyword">finally</span> { </span><br><span class="line"> workerGroup.shutdownGracefully(); <span class="comment">// 10</span></span><br><span class="line"> bossGroup.shutdownGracefully();</span><br><span class="line"> }</span><br><span class="line"> } </span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>消息处理类 DiscardServerHandler.java 代码<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">DiscardServerHandler</span> <span class="keyword">extends</span> <span class="title">ChannelHandlerAdapter</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> Logger logger = Logger.getLogger(DiscardServerHandler.class);</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">channelRead</span><span class="params">(ChannelHandlerContext ctx, Object msg)</span> </span>{</span><br><span class="line"> logger.info(<span class="string">"enter"</span>);</span><br><span class="line"> ByteBuf in = (ByteBuf)msg;</span><br><span class="line"> <span class="keyword">try</span> {</span><br><span class="line"> logger.info(<span class="string">"recv msg "</span> + in.toString(CharsetUtil.US_ASCII));</span><br><span class="line"> } <span class="keyword">finally</span> {</span><br><span class="line"> ((ByteBuf)msg).release();</span><br><span class="line"> }</span><br><span class="line"> } </span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">exceptionCaught</span><span class="params">(ChannelHandlerContext ctx, Throwable cause)</span> </span>{</span><br><span class="line"> cause.printStackTrace();</span><br><span class="line"> ctx.close();</span><br><span class="line"> } </span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>好，现在现从 DiscardServer 的第1步开始分析</p>
<ol>
<li>调用ServerBootstrap 的无参构造函数，实例化对象<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">ServerBootstrap b = <span class="keyword">new</span> ServerBootstrap(); </span><br><span class="line"><span class="comment">// 对应源码</span></span><br><span class="line"><span class="function"><span class="keyword">public</span> <span class="title">ServerBootstrap</span><span class="params">()</span> </span>{ } <span class="comment">// 什么也没干</span></span><br></pre></td></tr></table></figure>
</li>
</ol>
<p>其中ServerBootstrap 的继承关系<br><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">public class ServerBootstrap </span><br><span class="line"> public class AbstractBootstrap</span><br><span class="line"> public interface Cloneable</span><br></pre></td></tr></table></figure></p>
<ol>
<li>将父子事件管理器添加至ServerBootstrap中<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">b.group(bossGroup, workerGroup)</span><br></pre></td></tr></table></figure>
</li>
</ol>
<p>ServerBootstrap group 方法代码<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> ServerBootstrap <span class="title">group</span><span class="params">(EventLoopGroup parentGroup, EventLoopGroup childGroup)</span> </span>{</span><br><span class="line"> <span class="keyword">super</span>.group(parentGroup); <span class="comment">// 2.1 调用 父类AbstractBootstrap group 方法, 初始化父类事件管理器</span></span><br><span class="line"> <span class="keyword">if</span> (childGroup == <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> NullPointerException(<span class="string">"childGroup"</span>);</span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">if</span> (<span class="keyword">this</span>.childGroup != <span class="keyword">null</span>) { <span class="comment">// 如果已经存在则抛异常</span></span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> IllegalStateException(<span class="string">"childGroup set already"</span>);</span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">this</span>.childGroup = childGroup; <span class="comment">// 初始化子类时间管理器</span></span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">this</span>; <span class="comment">// 返回对象本身</span></span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>2.1. super.group(parentGroup);<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> B <span class="title">group</span><span class="params">(EventLoopGroup group)</span> </span>{</span><br><span class="line"> <span class="keyword">if</span> (group == <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> NullPointerException(<span class="string">"group"</span>);</span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">if</span> (<span class="keyword">this</span>.group != <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> IllegalStateException(<span class="string">"group set already"</span>);</span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">this</span>.group = group;</span><br><span class="line"> <span class="keyword">return</span> (B) <span class="keyword">this</span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>流程和ServerBootstrap.group 类似</p>
<ol>
<li>b.channel(NioServerSocketChannel.class)</li>
</ol>
<p>利用反射机制生成 SocketChannel 实例, 调用的是 AbstractBootstrap.channel<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> B <span class="title">channel</span><span class="params">(Class<? extends C> channelClass)</span> </span>{ </span><br><span class="line"> <span class="keyword">if</span> (channelClass == <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> NullPointerException(<span class="string">"channelClass"</span>);</span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">return</span> channelFactory(<span class="keyword">new</span> ReflectiveChannelFactory<C>(channelClass)); <span class="comment">// 3.1</span></span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>其中 NioServerSocketChannel 类的继承关系如下<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">NioServerSocketChannel</span> </span><br><span class="line"> <span class="title">public</span> <span class="title">class</span> <span class="title">AbstractNioMessageChannel</span></span><br><span class="line"> <span class="title">public</span> <span class="title">class</span> <span class="title">AbstractNioChannel</span></span><br><span class="line"> <span class="title">public</span> <span class="title">class</span> <span class="title">AbstractChannel</span></span><br><span class="line"> <span class="title">public</span> <span class="title">interface</span> <span class="title">Channel</span></span><br><span class="line"> <span class="title">public</span> <span class="title">interface</span> <span class="title">Comparable</span></span><br><span class="line"> <span class="title">public</span> <span class="title">interface</span> <span class="title">ServerSocketChannel</span></span><br><span class="line"> <span class="title">public</span> <span class="title">interface</span> <span class="title">ServerChannel</span></span><br><span class="line"> <span class="title">public</span> <span class="title">interface</span> <span class="title">Channel</span></span><br><span class="line"> <span class="title">public</span> <span class="title">interface</span> <span class="title">Comparable</span></span></span><br></pre></td></tr></table></figure></p>
<p>3.1. 调用AbstractBootstrap.channelFactory方法</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> B <span class="title">channelFactory</span><span class="params">(io.netty.channel.ChannelFactory<? extends C> channelFactory)</span> </span>{</span><br><span class="line"> <span class="keyword">return</span> channelFactory((ChannelFactory<C>) channelFactory); </span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">public</span> B <span class="title">channelFactory</span><span class="params">(ChannelFactory<? extends C> channelFactory)</span> </span>{ </span><br><span class="line"> <span class="keyword">if</span> (channelFactory == <span class="keyword">null</span>) { </span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> NullPointerException(<span class="string">"channelFactory"</span>); </span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">if</span> (<span class="keyword">this</span>.channelFactory != <span class="keyword">null</span>) { </span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> IllegalStateException(<span class="string">"channelFactory set already"</span>); </span><br><span class="line"> } </span><br><span class="line"> </span><br><span class="line"> <span class="keyword">this</span>.channelFactory = channelFactory; <span class="comment">// 设置 Channel 生成工厂实例即ReflectiveChannelFactory</span></span><br><span class="line"> <span class="keyword">return</span> (B) <span class="keyword">this</span>; </span><br><span class="line">}</span><br></pre></td></tr></table></figure>
<p>其中ReflectiveChannelFactory 类的继承关系<br><figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">public class ReflectiveChannelFactory </span><br><span class="line"> public interface ChannelFactory // io.netty.channel.ChannelFactory</span><br><span class="line"> public interface ChannelFactory // io.netty.bootstrap.channelFactory</span><br></pre></td></tr></table></figure></p>
<p>ReflectiveChannelFactory 的方法<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> <span class="title">ReflectiveChannelFactory</span><span class="params">(Class<? extends T> clazz)</span> </span>{ </span><br><span class="line"> <span class="keyword">if</span> (clazz == <span class="keyword">null</span>) { </span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> NullPointerException(<span class="string">"clazz"</span>); </span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">this</span>.clazz = clazz; <span class="comment">// 设置自己需要生成的Channel 实例类型</span></span><br><span class="line">} </span><br><span class="line"></span><br><span class="line"><span class="comment">// 工厂方法,后面会讲到其作用</span></span><br><span class="line"><span class="function"><span class="keyword">public</span> T <span class="title">newChannel</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="keyword">try</span> {</span><br><span class="line"> <span class="keyword">return</span> clazz.newInstance();</span><br><span class="line"> } <span class="keyword">catch</span> (Throwable t) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> ChannelException(<span class="string">"Unable to create Channel from class "</span> + clazz, t);</span><br><span class="line"> } </span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<ol>
<li>设置childHandler</li>
</ol>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line">b.childHandler(<span class="keyword">new</span> ChannelInitializer<SocketChannel>() {</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(SocketChannel ch)</span> </span>{</span><br><span class="line"> ch.pipeline().addLast(<span class="keyword">new</span> DiscardServerHandler()); <span class="comment">// 没来一次请求都放到pipeline 队列尾, 该函数由childHandler 调用</span></span><br><span class="line"> }</span><br><span class="line">});</span><br><span class="line"></span><br><span class="line"><span class="function"><span class="keyword">public</span> ServerBootstrap <span class="title">childHandler</span><span class="params">(ChannelHandler childHandler)</span> </span>{</span><br><span class="line"> <span class="keyword">if</span> (childHandler == <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> NullPointerException(<span class="string">"childHandler"</span>);</span><br><span class="line"> } </span><br><span class="line"> <span class="keyword">this</span>.childHandler = childHandler;</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">this</span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure>
<p>其中ChannelInitializer 的继承关系为<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">ChannelInitializer</span></span><br><span class="line"> <span class="title">public</span> <span class="title">class</span> <span class="title">ChannelHandlerAdapter</span> </span><br><span class="line"> <span class="title">public</span> <span class="title">interface</span> <span class="title">ChannelHandler</span> //定义了各种读写就绪接口</span></span><br></pre></td></tr></table></figure></p>
<p>5 6. 都是添加ChannelOption, option由AbstractBootstrap调用，childOption由ServerBootstrap调用</p>
<ol>
<li>ChannelFuture f = b.bind(port).sync();</li>
</ol>
<p>先看 bind 的实现逻辑<br>bind 在AbstractBootstrap 中有5个实现<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> ChannelFuture <span class="title">bind</span><span class="params">()</span> </span>{</span><br><span class="line"><span class="function"><span class="keyword">public</span> ChannelFuture <span class="title">bind</span><span class="params">(<span class="keyword">int</span> inetPort)</span> <span class="comment">// 本文中调用的</span></span><br><span class="line"><span class="keyword">public</span> ChannelFuture <span class="title">bind</span><span class="params">(String inetHost, <span class="keyword">int</span> inetPort)</span> </span><br><span class="line"><span class="keyword">public</span> ChannelFuture <span class="title">bind</span><span class="params">(InetAddress inetHost, <span class="keyword">int</span> inetPort)</span> </span><br><span class="line"><span class="keyword">public</span> ChannelFuture <span class="title">bind</span><span class="params">(SocketAddress localAddress)</span></span></span><br></pre></td></tr></table></figure></p>
<p>最终都调了 doBind方法<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">private</span> ChannelFuture <span class="title">doBind</span><span class="params">(<span class="keyword">final</span> SocketAddress localAddress)</span></span></span><br></pre></td></tr></table></figure></p>
<p>现在开始分析doBind 方法逻辑逻辑<br>AbstractBootstrap.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">private</span> ChannelFuture <span class="title">doBind</span><span class="params">(<span class="keyword">final</span> SocketAddress localAddress)</span> </span>{</span><br><span class="line"> <span class="keyword">final</span> ChannelFuture regFuture = initAndRegister();</span><br><span class="line"> <span class="keyword">final</span> Channel channel = regFuture.channel();</span><br><span class="line"> <span class="keyword">if</span> (regFuture.cause() != <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">return</span> regFuture;</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> (regFuture.isDone()) {</span><br><span class="line"> <span class="comment">// At this point we know that the registration was complete and successful.</span></span><br><span class="line"> ChannelPromise promise = channel.newPromise();</span><br><span class="line"> doBind0(regFuture, channel, localAddress, promise);</span><br><span class="line"> <span class="keyword">return</span> promise;</span><br><span class="line"> } <span class="keyword">else</span> {</span><br><span class="line"> <span class="comment">// Registration future is almost always fulfilled already, but just in case it's not.</span></span><br><span class="line"> <span class="keyword">final</span> PendingRegistrationPromise promise = <span class="keyword">new</span> PendingRegistrationPromise(channel);</span><br><span class="line"> regFuture.addListener(<span class="keyword">new</span> ChannelFutureListener() {</span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">operationComplete</span><span class="params">(ChannelFuture future)</span> <span class="keyword">throws</span> Exception </span>{</span><br><span class="line"> Throwable cause = future.cause();</span><br><span class="line"> <span class="keyword">if</span> (cause != <span class="keyword">null</span>) {</span><br><span class="line"> <span class="comment">// Registration on the EventLoop failed so fail the ChannelPromise directly to not cause an</span></span><br><span class="line"> <span class="comment">// IllegalStateException once we try to access the EventLoop of the Channel.</span></span><br><span class="line"> promise.setFailure(cause);</span><br><span class="line"> } <span class="keyword">else</span> {</span><br><span class="line"> <span class="comment">// Registration was successful, so set the correct executor to use.</span></span><br><span class="line"> <span class="comment">// See https://github.com/netty/netty/issues/2586</span></span><br><span class="line"> promise.executor = channel.eventLoop();</span><br><span class="line"> }</span><br><span class="line"> doBind0(regFuture, channel, localAddress, promise);</span><br><span class="line"> }</span><br><span class="line"> });</span><br><span class="line"> <span class="keyword">return</span> promise;</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>首先<br>AbstractBootstrap.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">final</span> ChannelFuture regFuture = initAndRegister();</span><br><span class="line"></span><br><span class="line"><span class="comment">// initAndRegister 方法逻辑</span></span><br><span class="line"><span class="function"><span class="keyword">final</span> ChannelFuture <span class="title">initAndRegister</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="comment">// 生成 NioServerSocketChannel 实例(之前channel 方法设定的)</span></span><br><span class="line"> <span class="keyword">final</span> Channel channel = channelFactory().newChannel(); <span class="comment">// 1</span></span><br><span class="line"> <span class="keyword">try</span> {</span><br><span class="line"> init(channel); <span class="comment">// 2</span></span><br><span class="line"> } <span class="keyword">catch</span> (Throwable t) {</span><br><span class="line"> channel.unsafe().closeForcibly();</span><br><span class="line"> <span class="comment">// as the Channel is not registered yet we need to force the usage of the GlobalEventExecutor</span></span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">new</span> DefaultChannelPromise(channel, GlobalEventExecutor.INSTANCE).setFailure(t);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> ChannelFuture regFuture = group().register(channel);</span><br><span class="line"> <span class="keyword">if</span> (regFuture.cause() != <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">if</span> (channel.isRegistered()) {</span><br><span class="line"> channel.close();</span><br><span class="line"> } <span class="keyword">else</span> {</span><br><span class="line"> channel.unsafe().closeForcibly();</span><br><span class="line"> }</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="comment">// If we are here and the promise is not failed, it's one of the following cases:</span></span><br><span class="line"> <span class="comment">// 1) If we attempted registration from the event loop, the registration has been completed at this point.</span></span><br><span class="line"> <span class="comment">// i.e. It's safe to attempt bind() or connect() now because the channel has been registered.</span></span><br><span class="line"> <span class="comment">// 2) If we attempted registration from the other thread, the registration request has been successfully</span></span><br><span class="line"> <span class="comment">// added to the event loop's task queue for later execution.</span></span><br><span class="line"> <span class="comment">// i.e. It's safe to attempt bind() or connect() now:</span></span><br><span class="line"> <span class="comment">// because bind() or connect() will be executed *after* the scheduled registration task is executed</span></span><br><span class="line"> <span class="comment">// because register(), bind(), and connect() are all bound to the same thread.</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> regFuture;</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>上述代码中 1 中 newInstance 方法进行分析<br>首先调用的是<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> <span class="title">NioServerSocketChannel</span><span class="params">()</span> </span>{ </span><br><span class="line"> <span class="keyword">this</span>(newSocket(DEFAULT_SELECTOR_PROVIDER));</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>其中 DEFAULT_SELECTOR_PROVIDER 定义为<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 这句话的最终结果就是获得java上层Selector Provider</span></span><br><span class="line"><span class="comment">// 据系统的不同，IO复用机制也不一样，比如linux 2.6以上使用时epoll,以下则是select/poll</span></span><br><span class="line"><span class="comment">// 为什么不用jdk自带的呢?或许这样性能会有所提高吧???</span></span><br><span class="line"><span class="comment">// 具体源码在 java/nio/channels/spi/SelectorProvider.java</span></span><br><span class="line"><span class="keyword">private</span> <span class="keyword">static</span> <span class="keyword">final</span> SelectorProvider DEFAULT_SELECTOR_PROVIDER = SelectorProvider.provider();</span><br></pre></td></tr></table></figure></p>
<p>接着newSocket 方法 => openServerSocketChannel[返回ServerSocketChannel] => 调用NioServerSocketChannel(返回ServerSocketChannel channel) 构造函数实例化<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"></span><br><span class="line"></span><br></pre></td></tr></table></figure></p>
<p>上述代码中 2 中 init 方法 源码实现如下<br>ServerBootstrap.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">void</span> <span class="title">init</span><span class="params">(Channel channel)</span> <span class="keyword">throws</span> Exception </span>{</span><br><span class="line"> <span class="comment">// 获取之前设置父类的options</span></span><br><span class="line"> <span class="keyword">final</span> Map<ChannelOption<?>, Object> options = options();</span><br><span class="line"> <span class="keyword">synchronized</span> (options) {</span><br><span class="line"> channel.config().setOptions(options);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="keyword">final</span> Map<AttributeKey<?>, Object> attrs = attrs();</span><br><span class="line"> <span class="keyword">synchronized</span> (attrs) {</span><br><span class="line"> <span class="keyword">for</span> (Entry<AttributeKey<?>, Object> e: attrs.entrySet()) {</span><br><span class="line"> <span class="annotation">@SuppressWarnings</span>(<span class="string">"unchecked"</span>)</span><br><span class="line"> AttributeKey<Object> key = (AttributeKey<Object>) e.getKey();</span><br><span class="line"> channel.attr(key).set(e.getValue());</span><br><span class="line"> }</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> ChannelPipeline p = channel.pipeline();</span><br><span class="line"></span><br><span class="line"> <span class="keyword">final</span> EventLoopGroup currentChildGroup = childGroup;</span><br><span class="line"> <span class="keyword">final</span> ChannelHandler currentChildHandler = childHandler;</span><br><span class="line"> <span class="keyword">final</span> Entry<ChannelOption<?>, Object>[] currentChildOptions;</span><br><span class="line"> <span class="keyword">final</span> Entry<AttributeKey<?>, Object>[] currentChildAttrs;</span><br><span class="line"> <span class="keyword">synchronized</span> (childOptions) {</span><br><span class="line"> currentChildOptions = childOptions.entrySet().toArray(newOptionArray(childOptions.size()));</span><br><span class="line"> }</span><br><span class="line"> <span class="keyword">synchronized</span> (childAttrs) {</span><br><span class="line"> currentChildAttrs = childAttrs.entrySet().toArray(newAttrArray(childAttrs.size()));</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> p.addLast(<span class="keyword">new</span> ChannelInitializer<Channel>() {</span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">initChannel</span><span class="params">(Channel ch)</span> <span class="keyword">throws</span> Exception </span>{</span><br><span class="line"> ChannelPipeline pipeline = ch.pipeline();</span><br><span class="line"> ChannelHandler handler = handler();</span><br><span class="line"> <span class="keyword">if</span> (handler != <span class="keyword">null</span>) {</span><br><span class="line"> pipeline.addLast(handler);</span><br><span class="line"> }</span><br><span class="line"> pipeline.addLast(<span class="keyword">new</span> ServerBootstrapAcceptor(</span><br><span class="line"> currentChildGroup, currentChildHandler, currentChildOptions, currentChildAttrs));</span><br><span class="line"> }</span><br><span class="line"> });</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
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<div class="date"> Sep 12 2015 </div>
<div class="article-title"><a href="/2015/09/12/java-blocking-queue-learn/" >java-blocking-queue-learn</a></div>
</h3>
<div class="entry">
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<p>Java BlockingQueue 接口在 java.util.concurrent中定义，他保证了线程线程间数据共享是安全的。这篇文章将会讲述 BlockingQueue 的使用。</p>
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<div class="date"> Sep 11 2015 </div>
<div class="article-title"><a href="/2015/09/11/java-volatile-keyword-learn/" >java-volatile-keyword-learn</a></div>
</h3>
<div class="entry">
<div class="row">
<div class="col-md-12">
<p>java volatile 变量写的同时会将之前线程内变量写的变量值同时 refresh in main memory</p>
<p>java volatile 变量读的同时，也会将线程内变量的值同时 refresh from main memory</p>
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<div class="date"> Sep 11 2015 </div>
<div class="article-title"><a href="/2015/09/11/java-concurrency-multithreading-learn/" >Java并发编程学习</a></div>
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<ol>
<li>模型更加复杂</li>
<li>上下文切换消耗资源</li>
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<div class="date"> Sep 8 2015 </div>
<div class="article-title"><a href="/2015/09/08/java-io-learning/" >java-io-learning</a></div>
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<div class="date"> Sep 7 2015 </div>
<div class="article-title"><a href="/2015/09/07/java-design-pattern-mediator/" >Java设计模式学习之中介者模式</a></div>
</h3>
<div class="entry">
<div class="row">
<div class="col-md-12">
<p>中介者模式是行为型模式的一种，他一般用于系统中不同对象间消息的统一处理，在GoF中这样介绍:</p>
<blockquote>
<p>通过某种封装，将不同对象松耦合，使之可以互相影响，消息可以互相转发，同时也允许不同对象互不依赖</p>
</blockquote>
<p>当某个应用出现很多对象互相影响时，中介者模式就派上用场了。如果对象之间是强耦合的，这样就会导致维护难度大大增大，不易扩展。而中介者模式可以使对象间松耦合。</p>
<p>飞机场广播就是一个很好的例子，提供了不同飞机之间消息转发的一种机制。对于模式来说的话，他一般是作为一个中间路由，就好比游戏服务中gateway服务一样。</p>
<p>系统中互相交流的对象，我们称之为同事(-_-)，我们通常用一个接口类或抽象类表示，然后针对不同的同事再实现具体类</p>
<h2 id="Mediator_Interface">Mediator Interface</h2><p>首先我们创建一个 Mediator Interface，定义了中介者是如何工作的</p>
<p>ChatMediator.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.MediatorDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">interface</span> <span class="title">CharMediator</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">sendMessage</span><span class="params">(String msg, User user)</span></span>;</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">addUser</span><span class="params">(User user)</span></span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<h2 id="Colleague_Interface">Colleague Interface</h2><p>同事间可以互相转发消息，可以将之定义为接口或抽象类，这里我把他定义为抽象类</p>
<p>User.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.MediatorDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="keyword">abstract</span> <span class="class"><span class="keyword">class</span> <span class="title">User</span> </span>{</span><br><span class="line"> CharMediator mediator;</span><br><span class="line"></span><br><span class="line"> String name;</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="title">User</span><span class="params">(CharMediator mediator, String name)</span> </span>{</span><br><span class="line"> <span class="keyword">this</span>.mediator = mediator;</span><br><span class="line"> <span class="keyword">this</span>.name = name;</span><br><span class="line"> } </span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">abstract</span> <span class="keyword">void</span> <span class="title">sendMessage</span><span class="params">(String msg)</span></span>;</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">abstract</span> <span class="keyword">void</span> <span class="title">receive</span><span class="params">(String msg)</span></span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>在每个同事的内部维护着中介者的引用，这样就可以和其他同事间互相交流了</p>
<h2 id="Concrete_Mediator">Concrete Mediator</h2><p>现在开始实现具体的中介者，该中介者内部维护这 Colleagues list，同时提供了同事间交流的逻辑</p>
<p>ChatMediatorImpl.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.MediatorDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> java.util.ArrayList;</span><br><span class="line"><span class="keyword">import</span> java.util.List;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> org.apache.log4j.Logger;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">CharMediatorImpl</span> <span class="keyword">implements</span> <span class="title">CharMediator</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> <span class="keyword">static</span> Logger logger = Logger.getLogger(CharMediatorImpl.class);</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> List<User> users = <span class="keyword">new</span> ArrayList<User>();</span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">sendMessage</span><span class="params">(String msg, User user)</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> <span class="keyword">for</span>(User u: users) {</span><br><span class="line"> <span class="keyword">if</span>(u != user) {</span><br><span class="line"> u.receive(msg);</span><br><span class="line"> } </span><br><span class="line"> } </span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">addUser</span><span class="params">(User user)</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> <span class="keyword">if</span>(user != <span class="keyword">null</span>) {</span><br><span class="line"> <span class="keyword">if</span>(!users.contains(user)) {</span><br><span class="line"> users.add(user);</span><br><span class="line"> } <span class="keyword">else</span> {</span><br><span class="line"> logger.warn(<span class="string">"add user name "</span> + user.getName() + <span class="string">" is already existing!!!"</span>);</span><br><span class="line"> } </span><br><span class="line"> } <span class="keyword">else</span> {</span><br><span class="line"> logger.warn(<span class="string">"add user param is null!!!"</span>);</span><br><span class="line"> } </span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<h2 id="Concrete_Colleague">Concrete Colleague</h2><p>现在我们开始实现具体的Colleagues</p>
<p>UserImpl.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.MediatorDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> org.apache.log4j.Logger;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">UserImpl</span> <span class="keyword">extends</span> <span class="title">User</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> <span class="keyword">static</span> Logger logger = Logger.getLogger(CharMediatorImpl.class);</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="title">UserImpl</span><span class="params">(CharMediator mediator, String name)</span> </span>{</span><br><span class="line"> <span class="keyword">super</span>(mediator, name);</span><br><span class="line"> } </span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">sendMessage</span><span class="params">(String msg)</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> logger.info(<span class="string">"User "</span> + <span class="keyword">this</span>.name + <span class="string">" send msg "</span> + msg + <span class="string">"!!!"</span>);</span><br><span class="line"> mediator.sendMessage(msg, <span class="keyword">this</span>);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">receive</span><span class="params">(String msg)</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> logger.info(<span class="string">"User "</span> + <span class="keyword">this</span>.name + <span class="string">" receive msg "</span> + msg + <span class="string">"!!!"</span>);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>在Colleague 进行发消息时，他是通过中介者来发送的，但是他是不知道中介者内部是如何处理的</p>
<h2 id="测试代码">测试代码</h2><p>现在我们开始测试已经实现的中介者模式，主要实现是，先往中介者中添加Colleagues，然后其中一个Colleague 发送消息来测试逻辑的正确性</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">testMediator</span><span class="params">()</span> </span>{</span><br><span class="line"> CharMediatorImpl mediator = <span class="keyword">new</span> CharMediatorImpl();</span><br><span class="line"> UserImpl walter = <span class="keyword">new</span> UserImpl(mediator, <span class="string">"walter"</span>);</span><br><span class="line"> mediator.addUser(walter);</span><br><span class="line"> mediator.addUser(<span class="keyword">new</span> UserImpl(mediator, <span class="string">"ym"</span>));</span><br><span class="line"> mediator.addUser(<span class="keyword">new</span> UserImpl(mediator, <span class="string">"cj"</span>));</span><br><span class="line"> mediator.addUser(<span class="keyword">new</span> UserImpl(mediator, <span class="string">"test"</span>));</span><br><span class="line"></span><br><span class="line"> walter.sendMessage(<span class="string">"Hello World"</span>);</span><br><span class="line">}</span><br></pre></td></tr></table></figure>
<p>解释结果<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">08</span> <span class="number">08</span>:<span class="number">27</span>:<span class="number">49</span> INFO com.walterlife.dp.MediatorDP.UserImpl sendMessage:<span class="number">16</span> -> User walter send msg Hello World!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">08</span> <span class="number">08</span>:<span class="number">27</span>:<span class="number">49</span> INFO com.walterlife.dp.MediatorDP.UserImpl receive:<span class="number">23</span> -> User ym receive msg Hello World!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">08</span> <span class="number">08</span>:<span class="number">27</span>:<span class="number">49</span> INFO com.walterlife.dp.MediatorDP.UserImpl receive:<span class="number">23</span> -> User cj receive msg Hello World!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">08</span> <span class="number">08</span>:<span class="number">27</span>:<span class="number">49</span> INFO com.walterlife.dp.MediatorDP.UserImpl receive:<span class="number">23</span> -> User test receive msg Hello World!!!</span><br></pre></td></tr></table></figure></p>
</div>
</div>
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<h3 class="title">
<div class="date"> Sep 7 2015 </div>
<div class="article-title"><a href="/2015/09/07/java-design-pattern-template-method/" >Java设计模式之模板方法模式</a></div>
</h3>
<div class="entry">
<div class="row">
<div class="col-md-12">
<p>模板方法模式是行为型模式中一种，他通常只需实现一个根方法即可，该方法规定了各个方法的执行顺序。这些方法中可以是各个子类共有的，也可以是每个子类不一样的，该模板方法是父类独有的，一般可以定义为final，可以防止子类进行重写</p>
<p>现在我们以造房子为例子，一般造房子都是以规定的顺序开工的，先打地基，再搭骨架，然后砌墙，最后上玻璃。其中地基是不同房子基本都是一样的，骨架有的可以是木头的，有的可以是砖块的，有的是玻璃，墙也是同样的。这里我们以玻璃房和木头房举例子，这两个子类都继承房子的基类(HouseTemplate),他们的buildPillars 和 buildWalls 方法是不同的，但是他们的建造顺序都是一样的，在HouseTemplate中的buildHouse中实现</p>
<p>其中为了父类中的模板方法不被子类重写，我们把该方法定义为 final 方法</p>
<h2 id="Template_Method_Abstract_Class">Template Method Abstract Class</h2><p>因为父类中有点方法是不需要实现的，模板方法又必须实现的，故将该类定义为 abstract class</p>
<p>HouseTemplate.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.TemplateMethodDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> org.apache.log4j.Logger;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="keyword">abstract</span> <span class="class"><span class="keyword">class</span> <span class="title">HouseTemplate</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> Logger logger = Logger.getLogger(HouseTemplate.class);</span><br><span class="line"></span><br><span class="line"> <span class="comment">// template method, order is fioxed</span></span><br><span class="line"> <span class="comment">// final so subclasses can not override it</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">final</span> <span class="keyword">void</span> <span class="title">buildHouse</span><span class="params">()</span> </span>{</span><br><span class="line"> buildFoudation();</span><br><span class="line"> buildPillers();</span><br><span class="line"> buildWalls();</span><br><span class="line"> buildWindows();</span><br><span class="line"> }</span><br><span class="line"> </span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">buildWindows</span><span class="params">()</span> </span>{</span><br><span class="line"> logger.info(<span class="string">"HouseTemplate build windows!!!"</span>);</span><br><span class="line"> } </span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">abstract</span> <span class="keyword">void</span> <span class="title">buildWalls</span><span class="params">()</span></span>;</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">abstract</span> <span class="keyword">void</span> <span class="title">buildPillers</span><span class="params">()</span></span>;</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">buildFoudation</span><span class="params">()</span> </span>{</span><br><span class="line"> logger.info(<span class="string">"HouseTemplate build foudation!!!"</span>);</span><br><span class="line"> } </span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>buildHouse() 是模板方法，该方法定义了建造房子固定的顺序</p>
<h2 id="Template_Method_Concrete_Classes">Template Method Concrete Classes</h2><p>这里我们只以 木头房和 玻璃房为例</p>
<p>WoodenHouse.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.TemplateMethodDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> org.apache.log4j.Logger;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">WoodenHouse</span> <span class="keyword">extends</span> <span class="title">HouseTemplate</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> Logger logger = Logger.getLogger(HouseTemplate.class);</span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">buildWalls</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> logger.info(<span class="string">"build house with wooden walls!!!"</span>); </span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">buildPillers</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> logger.info(<span class="string">"build house with wooden pills!!!"</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<p>GlassHouse.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.TemplateMethodDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> org.apache.log4j.Logger;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">GlassHouse</span> <span class="keyword">extends</span> <span class="title">HouseTemplate</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> Logger logger = Logger.getLogger(HouseTemplate.class);</span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">buildWalls</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> logger.info(<span class="string">"build house with glass walls!!!"</span>); </span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="annotation">@Override</span></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">buildPillers</span><span class="params">()</span> </span>{</span><br><span class="line"> <span class="comment">// TODO Auto-generated method stub</span></span><br><span class="line"> logger.info(<span class="string">"build house with glass pills!!!"</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<h2 id="Test_Method">Test Method</h2><p>现在开始测试我们刚刚实现的模板方法模式 代码</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="function"><span class="keyword">public</span> <span class="keyword">static</span> <span class="keyword">void</span> <span class="title">testTemplateMethod</span><span class="params">()</span> </span>{</span><br><span class="line"> HouseTemplate house = <span class="keyword">new</span> WoodenHouse();</span><br><span class="line"> house.buildHouse();</span><br><span class="line"> logger.info(<span class="string">"================================"</span>);</span><br><span class="line"></span><br><span class="line"> house = <span class="keyword">new</span> GlassHouse();</span><br><span class="line"> house.buildHouse();</span><br><span class="line">}</span><br></pre></td></tr></table></figure>
<p>输出<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.HouseTemplate buildFoudation:<span class="number">27</span> -> HouseTemplate build foudation!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.WoodenHouse buildPillers:<span class="number">18</span> -> build house with wooden pills!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.WoodenHouse buildWalls:<span class="number">12</span> -> build house with wooden walls!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.HouseTemplate buildWindows:<span class="number">19</span> -> HouseTemplate build windows!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.App testTemplateMethod:<span class="number">24</span> -> ================================</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.HouseTemplate buildFoudation:<span class="number">27</span> -> HouseTemplate build foudation!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.GlassHouse buildPillers:<span class="number">18</span> -> build house with glass pills!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.GlassHouse buildWalls:<span class="number">12</span> -> build house with glass walls!!!</span><br><span class="line"><span class="number">2015</span>-<span class="number">09</span>-<span class="number">07</span> <span class="number">22</span>:<span class="number">43</span>:<span class="number">28</span> INFO com.walterlife.dp.TemplateMethodDP.HouseTemplate buildWindows:<span class="number">19</span> -> HouseTemplate build windows!!!</span><br></pre></td></tr></table></figure></p>
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<h3 class="title">
<div class="date"> Sep 6 2015 </div>
<div class="article-title"><a href="/2015/09/06/java-design-pattern-proxy/" >Java设计模式学习之代理模式</a></div>
</h3>
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<p>代理模式是结构型模式中的一种，在GOF中有如下介绍</p>
<blockquote>
<p>为另外一个对象提供代理，以便可以访问该对象</p>
</blockquote>
<p>当我们需要实现控制访问的功能，就可以使用该模式</p>
<p>就拿linux系统命令而言，并不是所有的命令普通用户都可以执行的，这里linux系统的用户的权限管理模块就是一种代理，当用户想要执行命令时，最终都会代理到该模块，然后执行相应的命令</p>
<p>我们就简单的以执行命令为例子来实现代理模式</p>
<p>首先从接口开始编写代码</p>
<h2 id="接口类">接口类</h2><p>CommandExecutor.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.ProxyDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">interface</span> <span class="title">CommandExecuter</span> </span>{</span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">runCommand</span><span class="params">(String cmd)</span> <span class="keyword">throws</span> Exception</span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
<h2 id="接口实现类">接口实现类</h2><p>CommandExecutorImp.java<br><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">package</span> com.walterlife.dp.ProxyDP;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> java.io.IOException;</span><br><span class="line"></span><br><span class="line"><span class="keyword">import</span> org.apache.log4j.Logger;</span><br><span class="line"></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">CommandExecuterImpl</span> <span class="keyword">implements</span> <span class="title">CommandExecuter</span> </span>{</span><br><span class="line"></span><br><span class="line"> <span class="keyword">private</span> <span class="keyword">static</span> Logger logger = Logger.getLogger(CommandExecuter.class);</span><br><span class="line"></span><br><span class="line"> <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">runCommand</span><span class="params">(String cmd)</span> <span class="keyword">throws</span> IOException </span>{</span><br><span class="line"> Runtime.getRuntime().exec(cmd);</span><br><span class="line"> logger.info(<span class="string">"CommandExecuter run cmd: "</span> + cmd); </span><br><span class="line"> } </span><br><span class="line">}</span><br></pre></td></tr></table></figure></p>
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