JAVA远程连接linux服务器读取文件（JSch）

import com.jcraft.jsch.*;

import java.awt.*;

import javax.swing.*;

import java.io.*;

public class ScpFrom{

public static void main(String[] arg){

if(arg.length!=2){

System.err.println("usage: java ScpFrom user@remotehost:file1 file2");

System.exit(-1);

}

FileOutputStream fos=null;

try{

String user=arg[0].substring(0, arg[0].indexOf('@'));

arg[0]=arg[0].substring(arg[0].indexOf('@')+1);

String host=arg[0].substring(0, arg[0].indexOf(':'));

String rfile=arg[0].substring(arg[0].indexOf(':')+1);

String lfile=arg[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;

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

}

}

}

}