java实现两台linux服务器间下载上传传输文件

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.6</version>
</dependency>
<dependency>
    <groupId>com.jcraft</groupId>
    <artifactId>jsch</artifactId>
    <version>0.1.55</version>
</dependency>
<dependency>
    <groupId>ch.ethz.ganymed</groupId>
    <artifactId>ganymed-ssh2</artifactId>
    <version>build210</version>
</dependency>

/**
 * 下载和上传文件
 */
public class ScpClientUtil {
    private String ip;
    private int port;
    private String username;
    private String password;
    static private ScpClientUtil instance;
    static synchronized public ScpClientUtil getInstance(String ip, int port, String username, String passward) {
        if (instance == null) {
            instance = new ScpClientUtil(ip, port, username, passward);
        }
        return instance;
    }
    public ScpClientUtil(String ip, int port, String username, String passward) {
        this.ip = ip;
        this.port = port;
        this.username = username;
        this.password = passward;
    }
    public void getFile(String remoteFile, String localTargetDirectory) {
        Connection conn = new Connection(ip, port);
        try {
            conn.connect();
            boolean isAuthenticated = conn.authenticateWithPassword(username, password);
            if (!isAuthenticated) {
                System.err.println("authentication failed");
            }
            SCPClient client = new SCPClient(conn);
            client.get(remoteFile, localTargetDirectory);
        } catch (IOException ex) {
            ex.printStackTrace();
        }finally{
            conn.close();
        }
    }
    public void putFile(String localFile, String remoteTargetDirectory) {
        putFile(localFile, null, remoteTargetDirectory);
    }
    public void putFile(String localFile, String remoteFileName, String remoteTargetDirectory) {
        putFile(localFile, remoteFileName, remoteTargetDirectory,null);
    }
    public void putFile(String localFile, String remoteFileName, String remoteTargetDirectory, String mode) {
        Connection conn = new Connection(ip, port);
        try {
            conn.connect();
            boolean isAuthenticated = conn.authenticateWithPassword(username, password);
            if (!isAuthenticated) {
                System.err.println("authentication failed");
            }
            SCPClient client = new SCPClient(conn);
            if ((mode == null) || (mode.length() == 0)) {
                mode = "0600";
            }
            if (remoteFileName == null) {
                client.put(localFile, remoteTargetDirectory);
            } else {
                client.put(localFile, remoteFileName, remoteTargetDirectory, mode);
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }finally{
            conn.close();
        }
    }
    public static void main(String[] args) {
        ScpClientUtil scpClient = ScpClientUtil.getInstance("XXX", 22, "XXX", "XXX");
        // 从远程服务器/opt下的index.html下载到本地项目根路径下
        scpClient.getFile("/opt/index.html","./");
       // 把本地项目下根路径下的index.html上传到远程服务器/opt目录下
        scpClient.putFile("./index.html","/opt");
    }
}