在我的 Java SFTP class 中，为什么我得到这个 java.net.ConnectException？

Question

我正在使用名为 JSch 的 Java SFTP 库，这是我的代码：

package client;

import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.SftpException;

import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;

public class SFTPCode_2 {
    public SFTPCode_2() {
        super();
    }


    public static void main (String[] args) {
     SFTPCode_2 fileTransfer = new SFTPCode_2();              


       try {

           JSch jsch = new JSch();

           String host = "127.0.0.1";
           int port = 22;

           String user = "username";

           Session sessionRead = jsch.getSession(user, host, port);
           sessionRead.connect();

           Session sessionWrite = jsch.getSession(user, host, port);
           sessionWrite.connect();

           ChannelSftp channelRead = (ChannelSftp)sessionRead.openChannel("sftp");
           channelRead.connect();

           ChannelSftp channelWrite = (ChannelSftp)sessionWrite.openChannel("sftp");
           channelWrite.connect();

           PipedInputStream pin = new PipedInputStream(2048);
           PipedOutputStream pout = new PipedOutputStream(pin);

        /*  channelRead.rename("C:/Users/IBM_ADMIN/Desktop/Work/ConnectOne_Bancorp/Java_Work/SFTP_1/house.bmp",
                              "C:/Users/IBM_ADMIN/Desktop/Work/ConnectOne_Bancorp/Java_Work/SFTP_2/house.bmp"); */


           channelRead.get("C:/Users/IBM_ADMIN/Desktop/Work/ConnectOne_Bancorp/Java_Work/SFTP_1/house.bmp", pout);
           channelWrite.put(pin , "C:/Users/IBM_ADMIN/Desktop/Work/ConnectOne_Bancorp/Java_Work/SFTP_2/house.bmp"); 


           channelRead.disconnect();
           channelWrite.disconnect();

           sessionRead.disconnect();
           sessionWrite.disconnect();




       } catch( JSchException e) {
           e.printStackTrace(); }
         catch (SftpException e) {
           e.printStackTrace();
       } catch (IOException e) { 
           e.printStackTrace();
        }

    }
}

我正在尝试使用 JSch 库将文件从一个目录（在我的本地计算机中）复制到另一个目录。

但是它给我这个错误：

com.jcraft.jsch.JSchException: java.net.ConnectException: Connection refused: connect
    at com.jcraft.jsch.Util.createSocket(Util.java:349)
    at com.jcraft.jsch.Session.connect(Session.java:215)
    at com.jcraft.jsch.Session.connect(Session.java:183)
    at client.SFTPCode_2.main(SFTPCode_2.java:43)
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at java.net.Socket.connect(Socket.java:528)
    at java.net.Socket.<init>(Socket.java:425)
    at java.net.Socket.<init>(Socket.java:208)
    at com.jcraft.jsch.Util.createSocket(Util.java:343)
    ... 3 more
Process exited with exit code 0.

我尝试添加 Cygwin ( from link here )，但它仍然不起作用。

Answer 1

不清楚是哪一行抛出异常。尝试用 try/catch 包围每个 Jsch 动作，像这样：

        Session sessionRead = null;
        try {
            sessionRead = jsch.getSession(user, host, port);
        } catch (JSchException e) {
            System.out.println("Issue getting session.");
            e.printStackTrace();
        }

        try {
            sessionRead.connect(); // do you need to set properties first?
        } catch (JSchException e) {
            System.out.println("Issue connecting to session.");
            e.printStackTrace();
        }

对我来说，当我使用 Jsch 时，我必须添加会话属性来建立连接，例如，在 sessionRead.connect() 上。

        sessionRead.setPassword("password");
        sessionRead.setConfig("StrictHostKeyChecking", "no");
        sessionRead.connect();

在我的 Java SFTP class 中，为什么我得到这个 java.net.ConnectException？

In my Java SFTP class, why am I getting this java.net.ConnectException?

java

sftp

jsch