+

Author: vakinge

README.md

@@ -4,14 +4,26 @@
 java基础编码版面试题。
 
 #### 目录
- - 集合
- - io
-  - bio
-  - nio
-  - aio
-  - 本地io
- - 并发包
- - java8
- - 算法
-  - 排序算法
-  - 经典算法题
+* 基础
+  * [集合](docs/collection.md)
+  * [文件](docs/file.md)
+  * [网络I/O](docs/IO.md)
+  * [设计模式](docs/design-pattern.md)
+* 多线程
+  * [线程池](docs/concurrent-threadpool.md)
+  * [锁](docs/concurrent-lock.md)
+  * [队列](docs/concurrent-queue.md)
+  * [安全集合](docs/concurrent-collection.md)
+  * [工具](docs/concurrent-tool.md)
+* Java新特性
+  * [java 8](docs/java8.md)
+  * [java 9](docs/java9.md)
+  * [java 10](docs/java10.md)
+  * [java 11](docs/java11.md)
+* 算法
+  * [排序算法](docs/algorithm-sort.md)
+  * [加密算法](docs/algorithm-crypt.md)
+  * [其他算法](docs/algorithm-other.md)
+* 其他
+  * [正则表达式](docs/regex.md)
+  * [最佳实践](docs/best-practices.md)

docs/collection.md

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package io.vakin.base;
+package io.vakin.collection;
 
 /**
  * @description <br>

src/io/vakin/base/CollectionForeachRemoveElement.java renamed to src/io/vakin/collection/CollectionForeachRemoveElement.java

@@ -0,0 +1,22 @@
+package io.vakin.concurrent;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class CompletableFuture1 {
+
+    public static void main(String[] args) throws ExecutionException, InterruptedException {
+        CompletableFuture<String> future = new CompletableFuture<>();
+
+        future.complete("42");
+
+        future
+                .thenAccept(System.out::println)
+                .thenAccept(v -> System.out.println("done"));
+
+    }
+
+}

src/io/vakin/concurrent/CompletableFuture1.java

@@ -0,0 +1,31 @@
+package io.vakin.concurrent;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.LongAccumulator;
+import java.util.function.LongBinaryOperator;
+import java.util.stream.IntStream;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class LongAccumulator1 {
+
+    public static void main(String[] args) {
+        testAccumulate();
+    }
+
+    private static void testAccumulate() {
+        LongBinaryOperator op = (x, y) -> 2 * x + y;
+        LongAccumulator accumulator = new LongAccumulator(op, 1L);
+
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+
+        IntStream.range(0, 10)
+                .forEach(i -> executor.submit(() -> accumulator.accumulate(i)));
+
+        executor.shutdown();
+
+        System.out.format("Add: %d\n", accumulator.getThenReset());
+    }
+}

src/io/vakin/concurrent/LongAccumulator1.java

@@ -0,0 +1,43 @@
+package io.vakin.concurrent;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.LongAdder;
+import java.util.stream.IntStream;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class LongAdder1 {
+
+    private static final int NUM_INCREMENTS = 10000;
+
+    private static LongAdder adder = new LongAdder();
+
+    public static void main(String[] args) {
+        testIncrement();
+        testAdd();
+    }
+
+    private static void testAdd() {
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+
+        IntStream.range(0, NUM_INCREMENTS)
+                .forEach(i -> executor.submit(() -> adder.add(2)));
+
+        executor.shutdown();
+
+        System.out.format("Add: %d\n", adder.sumThenReset());
+    }
+
+    private static void testIncrement() {
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+
+        IntStream.range(0, NUM_INCREMENTS)
+                .forEach(i -> executor.submit(adder::increment));
+
+        executor.shutdown();
+
+        System.out.format("Increment: Expected=%d; Is=%d\n", NUM_INCREMENTS, adder.sumThenReset());
+    }
+}

src/io/vakin/concurrent/LongAdder1.java

@@ -2,6 +2,7 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -86,6 +87,21 @@ private static void test2() {
 
 		System.out.println(names);
 	}
+	
+	private static void testFindMax(){
+		List<Integer> intlist = Arrays.asList(1,2,3,4,5,6);
+		//error
+        int maxId = intlist.stream().max(Integer::max).get();
+        System.out.println("maxId = " + maxId);
+        
+        //right
+        maxId = intlist.stream().mapToInt(Integer::intValue).max().getAsInt();
+        System.out.println("maxId = " + maxId);
+
+        //right
+        maxId = intlist.stream().max(Comparator.comparing(Integer::intValue)).get();
+        System.out.println("maxId = " + maxId);
+	}
 
 	static class Person {
 		String name;

src/io/vakin/java8/StreamTest.java

@@ -1,4 +1,4 @@
-package io.vakin.base;
+package io.vakin.other;
 
 
 /**