连接方法，我看了一下和网上一样。但这种错误在网上没有搜索到。有遇到这个错误的，给点提示，谢谢。
public ChannelSftp connect(String host, int port, String username,
String password) {
ChannelSftp sftp = null;
try {
JSch jsch = new JSch();
jsch.getSession(username, host, port);
Session sshSession = jsch.getSession(username, host, port);
System.out.println("Session created.");
sshSession.setPassword(password);
Properties sshConfig = new Properties();
sshConfig.put("StrictHostKeyChecking", "no");
sshSession.setConfig(sshConfig);
sshSession.connect();
System.out.println("Session connected.");
System.out.println("Opening Channel.");
Channel channel = sshSession.openChannel("sftp");
channel.connect();
sftp = (ChannelSftp) channel;
System.out.println("Connected to " + host + ".");
} catch (Exception e) {
}
return sftp;
}
