我正在尝试使用JSch库在两个远程主机之间发送文件。我目前正在使用ScpFrom类来完成此操作。但是，我试图修改代码以允许我连接两个远程主机并发送文件，尽管看起来它只允许我将其从一个远程主机发送到本地计算机。我已经在JSch中尝试过SFTP类，但是没有运气。因此，请不要建议使用SFTP类。我将在下面列出我使用的代码：
代码：
/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/**
* This program will demonstrate the file transfer from remote to local
* $ CLASSPATH=.:../build javac ScpFrom.java
* $ CLASSPATH=.:../build java ScpFrom user@remotehost:file1 file2
* You will be asked passwd.
* If everything works fine, a file 'file1' on 'remotehost' will copied to
* local 'file1'.
*
*/
import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;
import java.io.*;
public class ScpFrom{
public static void main(String[] args){
String array [] = {"pf2rr1@paris44app1.linux.seis.com:/home/pf2rr1/test.txt","/home/pf2rr1/test"};
if(array.length!=2){
System.err.println("usage: java ScpFrom user@remotehost:file1 file2");
System.exit(-1);
}
FileOutputStream fos=null;
try{
String user=array[0].substring(0, array[0].indexOf('@'));
array[0]=array[0].substring(array[0].indexOf('@')+1);
String host=array[0].substring(0, array[0].indexOf(':'));
String rfile=array[0].substring(array[0].indexOf(':')+1);
String lfile=array[1];
String prefix=null;
if(new File(lfile).isDirectory()){
prefix=lfile+File.separator;
}
JSch jsch=new JSch();
Session session=jsch.getSession(user, host, 22);
// username and password will be given via UserInfo interface.
UserInfo ui=new MyUserInfo();
session.setUserInfo(ui);
session.connect();
// exec 'scp -f rfile' remotely
String command="scp -f "+rfile;
System.out.println(command);
Channel channel=session.openChannel("exec");
((ChannelExec)channel).setCommand(command);
// get I/O streams for remote scp
OutputStream out=channel.getOutputStream();
InputStream in=channel.getInputStream();
channel.connect();
byte[] buf=new byte[1024];
// send '\0'
buf[0]=0; out.write(buf, 0, 1); out.flush();
while(true){
int c=checkAck(in);
if(c!='C'){
break;
}
// read '0644 '
in.read(buf, 0, 5);
long filesize=0L;
while(true){
if(in.read(buf, 0, 1)<0){
// error
break;
}
if(buf[0]==' ')break;
filesize=filesize*10L+(long)(buf[0]-'0');
}
String file=null;
for(int i=0;;i++){
in.read(buf, i, 1);
if(buf[i]==(byte)0x0a){
file=new String(buf, 0, i);
break;
}
}
//System.out.println("filesize="+filesize+", file="+file);
// send '\0'
buf[0]=0; out.write(buf, 0, 1); out.flush();
// read a content of lfile
fos=new FileOutputStream(prefix==null ? lfile : prefix+file);
int foo;
while(true){
if(buf.length<filesize) foo=buf.length;
else foo=(int)filesize;
foo=in.read(buf, 0, foo);
if(foo<0){
// error
break;
}
fos.write(buf, 0, foo);
filesize-=foo;
if(filesize==0L) break;
}
fos.close();
fos=null;
if(checkAck(in)!=0){
System.exit(0);
}
// send '\0'
buf[0]=0; out.write(buf, 0, 1); out.flush();
}
session.disconnect();
System.exit(0);
}
catch(Exception e){
System.out.println(e);
try{if(fos!=null)fos.close();}catch(Exception ee){}
}
}
static int checkAck(InputStream in) throws IOException{
int b=in.read();
// b may be 0 for success,
// 1 for error,
// 2 for fatal error,
// -1
if(b==0) return b;
if(b==-1) return b;
if(b==1 || b==2){
StringBuffer sb=new StringBuffer();
int c;
do {
c=in.read();
sb.append((char)c);
}
while(c!='\n');
if(b==1){ // error
System.out.print(sb.toString());
}
if(b==2){ // fatal error
System.out.print(sb.toString());
}
}
return b;
}
public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
public String getPassword(){ return passwd; }
public boolean promptYesNo(String str){
Object[] options={ "yes", "no" };
int foo=JOptionPane.showOptionDialog(null,
str,
"Warning",
JOptionPane.DEFAULT_OPTION,
JOptionPane.WARNING_MESSAGE,
null, options, options[0]);
return foo==0;
}
String passwd;
JTextField passwordField=(JTextField)new JPasswordField(20);
public String getPassphrase(){ return null; }
public boolean promptPassphrase(String message){ return true; }
public boolean promptPassword(String message){
Object[] ob={passwordField};
int result=
JOptionPane.showConfirmDialog(null, ob, message,
JOptionPane.OK_CANCEL_OPTION);
if(result==JOptionPane.OK_OPTION){
passwd=passwordField.getText();
return true;
}
else{ return false; }
}
public void showMessage(String message){
JOptionPane.showMessageDialog(null, message);
}
final GridBagConstraints gbc =
new GridBagConstraints(0,0,1,1,1,1,
GridBagConstraints.NORTHWEST,
GridBagConstraints.NONE,
new Insets(0,0,0,0),0,0);
private Container panel;
public String[] promptKeyboardInteractive(String destination,
String name,
String instruction,
String[] prompt,
boolean[] echo){
panel = new JPanel();
panel.setLayout(new GridBagLayout());
gbc.weightx = 1.0;
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.gridx = 0;
panel.add(new JLabel(instruction), gbc);
gbc.gridy++;
gbc.gridwidth = GridBagConstraints.RELATIVE;
JTextField[] texts=new JTextField[prompt.length];
for(int i=0; i<prompt.length; i++){
gbc.fill = GridBagConstraints.NONE;
gbc.gridx = 0;
gbc.weightx = 1;
panel.add(new JLabel(prompt[i]),gbc);
gbc.gridx = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.weighty = 1;
if(echo[i]){
texts[i]=new JTextField(20);
}
else{
texts[i]=new JPasswordField(20);
}
panel.add(texts[i], gbc);
gbc.gridy++;
}
if(JOptionPane.showConfirmDialog(null, panel,
destination+": "+name,
JOptionPane.OK_CANCEL_OPTION,
JOptionPane.QUESTION_MESSAGE)
==JOptionPane.OK_OPTION){
String[] response=new String[prompt.length];
for(int i=0; i<prompt.length; i++){
response[i]=texts[i].getText();
}
return response;
}
else{
return null; // cancel
}
}
}
}
答案 0 :(得分：2)
SCP协议（ScpFrom类）不能用于在两个远程主机之间直接传输。
对于两个远程主机之间的SCP文件，只需在一台主机上执行scp命令即可将该文件传输到另一台主机。这就是scp tool在内部执行的操作，当您使用语法执行该操作时：
scp user@host1:file user@host2:dest
它连接到host1并在其中执行：
scp file user@host2:dest
因此，当session连接到host1时，请执行以下操作：
String command = "scp file user@host2:dest";
Channel channel = session.openChannel("exec");
((ChannelExec)channel).setCommand(command);
channel.connect();
// ...