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/