如果大家熟悉Linux的話，一定對ssh,sftp,scp等命令非常熟悉，
ssh是一個安全協議，用來在不同系統或者服務器之間進行安全連接，SSH 在連接和傳送的過程中會加密所有的數據。
但是SSH一般是基於客戶端的或者Linux命令行的，比如客戶端的工具:OpenSSH,putty,SSH Tectia；
在linux上大家可以通過ssh username@host連接到所要想連接的主機。
但是如果在J2EE中，如何實現SSH呢？進而可以實現SCP,SFTP的功能呢？下面介紹的JSCH就可以實現下邊的功能。
JSCH是一個純粹的用java實現SSH功能的java library;
maven依賴
<dependency> <groupId>com.jcraft</groupId> <artifactId>jsch</artifactId> <version>0.1.44</version></dependency>
關鍵類介紹
- JSch: 作為中心配置點，以及Session的工廠；
- Use getSession to start a new Session.
- Use one of the addIdentity methods for public-key authentication.
- Use setKnownHosts to enable checking of host keys.
- See setConfig for a list of configuration options.
- Session：表示到遠程SSH服務器的一個連接，可以包含多個Channels；
A session is opened with connect() and closed with disconnect().
- Channel : 與Session相關聯的通道，有多種不同類型；
- shell - ChannelShell ：A channel connected to a remote shell (本次使用的Channel)
- exec - ChannelExec ：A channel connected to a remotely executing program
- direct-tcpip - ChannelDirectTCPIP： A Channel which allows forwarding a pair of local streams to/from a TCP-connection to a server on the remote side
- sftp - ChannelSftp ：A Channel connected to an sftp server (as a subsystem of the ssh server).
- subsystem - ChannelSubsystem ：A channel connected to a subsystem of the server process
使用步驟
使用Jsch進行SSH連接的具體步驟如下:
- 步驟1： 使用Jsch獲取Session: jsch.getSession()
- 步驟2： 設置Session的password和屬性等: setPassword()/setConfig();
- 步驟3： 設置SocketFactory（可以不進行設置,使用默認的TCP socket）;
- 步驟4： 打開Session連接：connect();
- 步驟5： 打開並連接Channel：openChannel()/connect();
- 步驟6： 獲取Channel的inputStream和outputStream，執行指定cmd或其他；
- getInputStream(): All data arriving in SSH_MSG_CHANNEL_DATA messages from the remote side can be read from this stream
- getOutputStream(): All data written to this stream will be sent in SSH_MSG_CHANNEL_DATA messages to the remote side.
- 步驟7： 關閉各種資源：輸入輸出流/Session/Channel等；
創建Session，並打開Session連接
步驟1~步驟4：程序如下
使用SSH協議，連接到Linux，執行指定命令，並獲取結果
步驟5~步驟6：程序如下
執行Shell命令，並獲取執行結果
測試程序
完整程序
JSCHUtil.java
package com.sssppp.Communication;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.InetAddress;import java.net.InetSocketAddress;import java.net.Socket;import java.net.UnknownHostException;import java.util.Properties;import com.jcraft.jsch.JSch;import com.jcraft.jsch.JSchException;import com.jcraft.jsch.Session;import com.jcraft.jsch.SocketFactory;/** * 相關鏈接： JSCH api：http://epaul.github.io/jsch-documentation/javadoc/ Example: * http://www.jcraft.com/jsch/examples/ * * @author xxxx * */public class JSCHUtil { private static JSch jsch = new JSch(); /** * 創建Session，並打開Session連接 * * @param dstIp * @param dstPort * @param localIp * @param localPort * @param userName * @param password * @param timeOut * @return * @throws JSchException */ public static Session createSession(String dstIp, int dstPort, final String localIp, final int localPort, String userName, String password, final int timeOut) throws JSchException { //jsch.setKnownHosts("/home/foo/.ssh/known_hosts"); // A Session represents a connection to a SSH server Session session = jsch.getSession(userName, dstIp, dstPort); session.setPassword(password); Properties sshConfig = new Properties(); sshConfig.put("StrictHostKeyChecking", "no");//To skip host-key check session.setConfig(sshConfig); // this socket factory is used to create a socket to the target host, // and also create the streams of this socket used by us session.setSocketFactory(new SocketFactory() { @Override public OutputStream getOutputStream(Socket socket) throws IOException { return socket.getOutputStream(); } @Override public InputStream getInputStream(Socket socket) throws IOException { return socket.getInputStream(); } @Override public Socket createSocket(String host, int port) throws IOException, UnknownHostException { Socket socket = new Socket(); if (localIp != null) { socket.bind(new InetSocketAddress(InetAddress .getByName(localIp), localPort)); } socket.connect( new InetSocketAddress(InetAddress.getByName(host), port), timeOut); return socket; } }); session.connect(timeOut); return session; }}
SSHCommUtil.java
package com.sssppp.Communication;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import com.jcraft.jsch.Channel;import com.jcraft.jsch.JSchException;import com.jcraft.jsch.Session;public class SSHCommUtil { /** * 測試程序 * @param args */ public static void main(String[] args) { String ip = "10.180.137.241"; int port = 22; String localIp = null; int localPort = 0; int timeOut = 3000; String userName = "xxx"; String password = "xxx"; String[] cmds = new String[] { "ifconfig | grep eth0\n", "cat /etc/redhat-release\n" }; String[] result = null; try { result = execShellCmdBySSH(ip, port, localIp, localPort, timeOut, userName, password, cmds); } catch (Exception e) { e.printStackTrace(); } if (result != null) { for (String string : result) { System.out.println(string); System.out.println("-------------------"); } } } /** * 使用SSH協議，連接到Linux Shell，執行腳本命令，並獲取結果 * * @param dstIp * @param dstport * default :22 * @param localIp * @param localPort * @param timeOut * @param userName * @param password * @param cmds * @return * @throws Exception */ public static String[] execShellCmdBySSH(String dstIp, int dstport, String localIp, int localPort, int timeOut, String userName, String password, String... cmds) throws Exception { Session session = null; Channel channel = null; InputStream is = null; OutputStream os = null; try { session = JSCHUtil.createSession(dstIp, dstport, localIp, localPort, userName, password, timeOut); channel = session.openChannel("shell"); // Enable agent-forwarding. // ((ChannelShell)channel).setAgentForwarding(true); // Choose the pty-type "vt102". // ((ChannelShell)channel).setPtyType("vt102"); // Set environment variable "LANG" as "ja_JP.eucJP". // ((ChannelShell)channel).setEnv("LANG", "ja_JP.eucJP"); channel.connect(); is = channel.getInputStream(); os = channel.getOutputStream(); String[] result = new String[cmds.length]; for (int i = 0; i < cmds.length; i++) { result[i] = sendCommand(is, os, cmds[i]); } return result; } catch (JSchException e) { if (e.getMessage().contains("Auth fail")) { throw new Exception("Auth error"); } else { throw new Exception("Connect error"); } } catch (Exception e) { throw e; } finally { try { is.close(); } catch (IOException e) { } try { os.close(); } catch (IOException e) { } channel.disconnect(); session.disconnect(); } } /** * 執行Shell命令，並獲取執行結果 * * @param is * @param os * @param cmd * @return * @throws IOException */ private static String sendCommand(InputStream is, OutputStream os, String cmd) throws IOException { os.write(cmd.getBytes()); os.flush(); StringBuffer sb = new StringBuffer(); int beat = 0; while (true) { if (beat > 3) { break; } if (is.available() > 0) { byte[] b = new byte[is.available()]; is.read(b); sb.append(new String(b)); beat = 0; } else { if (sb.length() > 0) { beat++; } try { Thread.sleep(sb.toString().trim().length() == 0 ? 1000 : 300); } catch (InterruptedException e) { } } } return sb.toString(); }}