Merge remote-tracking branch 'fork/21'

src/main/java/com/jcabi/ssh/Execution.java

@@ -0,0 +1,171 @@
+/**
+ * Copyright (c) 2014-2015, jcabi.com
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met: 1) Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer. 2) Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution. 3) Neither the name of the jcabi.com nor
+ * the names of its contributors may be used to endorse or promote
+ * products derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
+ * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.jcabi.ssh;
+
+import com.jcabi.log.Logger;
+import com.jcraft.jsch.ChannelExec;
+import com.jcraft.jsch.JSchException;
+import com.jcraft.jsch.Session;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Execution of a single command.
+ * @author Georgy Vlasov ([email protected])
+ * @version $Id$
+ * @since 1.4
+ */
+interface Execution {
+    /**
+     * Executes some command.
+     * @return Return code of the command.
+     * @throws IOException If fails
+     */
+    int exec() throws IOException;
+
+    /**
+     * Execution of a command in an SSH session.
+     * @author Georgy Vlasov ([email protected])
+     * @version $Id$
+     * @since 1.4
+     */
+    final class Default implements Execution {
+        /**
+         * Command.
+         */
+        private final transient String command;
+
+        /**
+         * Stdin.
+         */
+        private final transient InputStream stdin;
+
+        /**
+         * Stdout.
+         */
+        private final transient OutputStream stdout;
+
+        /**
+         * Stderr.
+         */
+        private final transient OutputStream stderr;
+
+        /**
+         * Session.
+         */
+        private final transient Session session;
+
+        /**
+         * Uses an SSH session to execute a single command and disconnect
+         * immediately.
+         * @param cmd Command
+         * @param input Stdin (will be closed)
+         * @param out Stdout (will be closed)
+         * @param err Stderr (will be closed)
+         * @param sess SSH session (will be disconnected)
+         * @checkstyle ParameterNumberCheck (6 lines)
+         */
+        Default(final String cmd, final InputStream input,
+            final OutputStream out, final OutputStream err,
+            final Session sess) {
+            this.command = cmd;
+            this.stdin = input;
+            this.stdout = out;
+            this.stderr = err;
+            this.session = sess;
+        }
+
+        /**
+         * Execute {@link #command} in {@link #session}.
+         * @return Exit code
+         * @throws IOException If fails
+         */
+        @Override
+        public int exec() throws IOException {
+            try {
+                final ChannelExec channel = ChannelExec.class.cast(
+                    this.session.openChannel("exec")
+                );
+                channel.setErrStream(this.stderr, false);
+                channel.setOutputStream(this.stdout, false);
+                channel.setInputStream(this.stdin, false);
+                channel.setCommand(this.command);
+                channel.connect();
+                Logger.info(this, "$ %s", this.command);
+                return this.exec(channel);
+            } catch (final JSchException ex) {
+                throw new IOException(ex);
+            } finally {
+                this.session.disconnect();
+            }
+        }
+
+        /**
+         * Exec this channel and return its exit code.
+         * @param channel The channel to exec
+         * @return Exit code (zero in case of success)
+         * @throws IOException If fails
+         */
+        private int exec(final ChannelExec channel) throws IOException {
+            try {
+                return this.code(channel);
+            } finally {
+                channel.disconnect();
+            }
+        }
+
+        /**
+         * Wait until it's done and return its code.
+         * @param exec The channel
+         * @return The exit code
+         * @throws IOException If some IO problem inside
+         */
+        @SuppressWarnings("PMD.AvoidCatchingGenericException")
+        private int code(final ChannelExec exec) throws IOException {
+            while (!exec.isClosed()) {
+                try {
+                    this.session.sendKeepAliveMsg();
+                    // @checkstyle IllegalCatch (1 line)
+                } catch (final Exception ex) {
+                    throw new IOException(ex);
+                }
+                try {
+                    TimeUnit.SECONDS.sleep(1L);
+                } catch (final InterruptedException ex) {
+                    Thread.currentThread().interrupt();
+                    throw new IOException(ex);
+                }
+            }
+            return exec.getExitStatus();
+        }
+    }
+}

src/main/java/com/jcabi/ssh/SSH.java

@@ -32,7 +32,6 @@
 import com.jcabi.aspects.RetryOnFailure;
 import com.jcabi.aspects.Tv;
 import com.jcabi.log.Logger;
-import com.jcraft.jsch.ChannelExec;
 import com.jcraft.jsch.JSch;
 import com.jcraft.jsch.JSchException;
 import com.jcraft.jsch.Session;
@@ -68,6 +67,9 @@
  * <p>It is highly recommended to use classes from {@link Shell} interface,
  * they will simplify operations.</p>
  *
+ * @todo #21:30min This class has common data, implementation of exec() and
+ *  constructor validations with SSHByPassword class. Common functionality
+ *  should be extracted into a separate module.
  * @author Yegor Bugayenko ([email protected])
  * @version $Id$
  * @since 1.0
@@ -214,25 +216,9 @@ public SSH(final String adr, final int prt,
     public int exec(final String command, final InputStream stdin,
         final OutputStream stdout, final OutputStream stderr)
         throws IOException {
-        try {
-            final Session session = this.session();
-            try {
-                final ChannelExec channel = ChannelExec.class.cast(
-                    session.openChannel("exec")
-                );
-                channel.setErrStream(stderr, false);
-                channel.setOutputStream(stdout, false);
-                channel.setInputStream(stdin, false);
-                channel.setCommand(command);
-                channel.connect();
-                Logger.info(this, "$ %s", command);
-                return this.exec(channel, session);
-            } finally {
-                session.disconnect();
-            }
-        } catch (final JSchException ex) {
-            throw new IOException(ex);
-        }
+        return new Execution.Default(
+            command, stdin, stdout, stderr, this.session()
+        ).exec();
     }
 
     /**
@@ -244,49 +230,6 @@ public static String escape(final String arg) {
         return String.format("'%s'", arg.replace("'", "'\\''"));
     }
 
-    /**
-     * Exec this channel and return its exit code.
-     * @param channel The channel to exec
-     * @param session The session
-     * @return Exit code (zero in case of success)
-     * @throws IOException If fails
-     */
-    private int exec(final ChannelExec channel, final Session session)
-        throws IOException {
-        try {
-            return this.code(channel, session);
-        } finally {
-            channel.disconnect();
-        }
-    }
-
-    /**
-     * Wait until it's done and return its code.
-     * @param exec The channel
-     * @param session The session
-     * @return The exit code
-     * @throws IOException If some IO problem inside
-     */
-    @SuppressWarnings("PMD.AvoidCatchingGenericException")
-    private int code(final ChannelExec exec, final Session session)
-        throws IOException {
-        while (!exec.isClosed()) {
-            try {
-                session.sendKeepAliveMsg();
-                // @checkstyle IllegalCatch (1 line)
-            } catch (final Exception ex) {
-                throw new IOException(ex);
-            }
-            try {
-                TimeUnit.SECONDS.sleep(1L);
-            } catch (final InterruptedException ex) {
-                Thread.currentThread().interrupt();
-                throw new IOException(ex);
-            }
-        }
-        return exec.getExitStatus();
-    }
-
     /**
      * Create and return a session, connected.
      * @return JSch session