Java执行SSH/SCP之JSch

JSch （Java Secure Channel）是纯Java的SSH2实现。可以把它集成到你的Java应用中来连接sshd服务器，执行指令（port forward, file transfer, terminal emulation）。Ant、Eclipse-CVSSSH2、NetBeans等工具都在使用它。如果你的服务部署在linux服务器中，有时你需要执行一些系统命令，这时候需要用到Runtime.getRuntime().exec("java -version"); 但是这样会让你的服务器内存瞬间增长很多。JSch基于JavaTM Cryptography Extension(JCE)通过Socket来实现通信，可以大大减少内存的暴涨。

http://www.jcraft.com/

版本：jsch-0.1.51.jar

SSH例子：

public void ssh() throws Exception {
	JSch jsch = new JSch();

	// connect session
	Session session = jsch.getSession(USER_ID, HOST_NAME, 22);
	session.setPassword(PASSWORD);
	session.setConfig("StrictHostKeyChecking", "no");
	session.connect();

	// exec command remotely
	String command = "ls -l";
	ChannelExec channel = (ChannelExec) session.openChannel("exec");
	channel.setCommand(command);
	channel.connect();

	// get stdout
	InputStream in = channel.getInputStream();
	byte[] tmp = new byte[1024];
	while (true) {
		while (in.available() > 0) {
			int i = in.read(tmp, 0, 1024);
			if (i < 0)
				break;
			System.out.print(new String(tmp, 0, i));
		}
		if (channel.isClosed()) {
			System.out.println("exit-status: " + channel.getExitStatus());
			break;
		}
		try {
			Thread.sleep(1000);
		} catch (Exception ee) {
		}
	}
	channel.disconnect();
	session.disconnect();
}

SFTP例子：

public void sftp() throws Exception {
	JSch jsch = new JSch();
	
	// connect session
	Session session = jsch.getSession(USER_ID, HOST_NAME, 22);
	session.setPassword(PASSWORD);
	session.setConfig("StrictHostKeyChecking", "no");
	session.connect();

	// sftp remotely
	ChannelSftp channel = (ChannelSftp) session.openChannel("sftp");
	channel.connect();

	// ls
	Vector list = channel.ls(".");
	System.out.println("---- ls");
	for (int i = 0; i < list.size(); i++) {
		System.out.println(list.get(i));
	}

	// lstat
	try {
		SftpATTRS stat = channel.lstat("index.html");
		System.out.println("---- lstat");
		System.out.println(stat);
		System.out.println(stat.getSize());
	} catch (SftpException ex) {
		ex.printStackTrace();
	}

	// get
	channel.get("./index.html", "./index.html.dst");
	// put
	channel.put(new FileInputStream("c:/test.txt"), "test_new.txt");

	channel.disconnect();
	session.disconnect();
}

其他的工具还有：
Ganymed SSH-2： https://code.google.com/p/ganymed-ssh-2/
sshj ： https://github.com/shikhar/sshj
Apache SSHD： http://mina.apache.org/sshd-project/