在我的Java SFTP類中，為什么會收到此java.net.ConnectException？

Question

我正在使用一個名為JSch的Java SFTP庫，這是我的代碼：

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();
        }

    }
}

我正在嘗試使用JSch庫將文件從一個目錄（在本地計算機內）復制到另一個目錄。

但這給了我這個錯誤：

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.

我嘗試添加Cygwin（ 從此處的鏈接 ），但仍然無法正常工作。

Answer 1

目前尚不清楚哪一行引發了異常。 嘗試用try / catch包圍每個Jsch動作，如下所示：

        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();
        }

對我來說，當我使用Jsch時，我必須添加會話屬性以建立連接，例如在sessionRead.connect（）上。

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