用 TCP 协议写一个客户端和一个服务端，实现上传文件

package com.heima.test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Test20_2 {

/**用 TCP 协议写一个客户端和一个服务端，实现上传文件
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
ServerSocket server = new ServerSocket(6060);
System.out.println("服务器绑定成功！绑定6060端口！");
while(true){
final Socket socket = server.accept();
new Thread(){
public void run(){
try {
InputStream is = socket.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
PrintStream ps = new PrintStream(socket.getOutputStream());
String fileName = br.readLine();

File dir = new File("updata");
dir.mkdir();
File file = new File(dir,fileName);

if(file.exists()){
ps.println("存在！");
socket.close();
return;
}else{
ps.println("不存在！");
}

FileOutputStream fos = new FileOutputStream(file);
byte []arr = new byte[8192];
int len;
while((len = is.read(arr)) != -1){
fos.write(arr,0,len);
}
fos.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}

}

}.start();
}
}

}