import java.io.InputStream;

import java.io.OutputStream;

import java.net.Socket;

public class FTPClient{

public static void main(String[] args) throws Exception{

Socket socket = new Socket("192.168.0.1",21);

InputStream is = socket.getInputStream();

OutputStream os = socket.getOutputStream();

//接收初始链接信息

byte[] buffer = new byte[100];

int length = is.read(buffer);

String s = new String(buffer, 0, length);

System.out.println(s);

//发送用户名

String str = "USER useway\n";

os.write(str.getBytes());

//得到返回值

length = is.read(buffer);

s = new String(buffer, 0, length);

System.out.println(s);

//发送密码

str = "PASS !@#$%abcd\n";

os.write(str.getBytes());

//得到返回值

length = is.read(buffer);

s = new String(buffer, 0, length);

System.out.println(s);

//发送切换文件夹指令

str = "CWD /home/useway\n";

os.write(str.getBytes());

//得到返回值

length = is.read(buffer);

s = new String(buffer, 0, length);

System.out.println(s);

//设置模式

str = "EPSV ALL\n";

os.write(str.getBytes());

//得到返回值

length = is.read(buffer);

s = new String(buffer, 0, length);

System.out.println(s);

//得到被动监听信息

str = "EPSV\n";

os.write(str.getBytes());

//得到返回值

length = is.read(buffer);

s = new String(buffer, 0, length);

System.out.println(s);

//取得FTP被动监听的端口号

String portlist=s.substring(s.indexOf("(|||")+4,s.indexOf("|)"));

System.out.println(portlist);

//实例化ShowList线程类，链接FTP被动监听端口号

ShowList sl=new ShowList();

sl.port=Integer.parseInt(portlist);

sl.start();

//执行LIST命令

str = "LIST\n";

os.write(str.getBytes());

//得到返回值

length = is.read(buffer);

s = new String(buffer, 0, length);

System.out.println(s);

//关闭链接

is.close();

os.close();

socket.close();

}

}

//得到被动链接信息类，这个类是多线程的

class ShowList extends Thread{

public int port=0;

public void run(){

try{

Socket socket = new Socket("192.168.0.1",this.port);

InputStream is = socket.getInputStream();

OutputStream os = socket.getOutputStream();

byte[] buffer = new byte[10000];

int length = is.read(buffer);

String s = new String(buffer, 0, length);

System.out.println(s);

//关闭链接

is.close();

os.close();

socket.close();

}

catch(Exception ex){

}

}

}