TCP协议实现客户端发送小写字母收到大写字母

TransServer

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class TransServer {

	public static void main(String[] args) throws Exception {
		ServerSocket ss=new ServerSocket(9999);
		//获取socket对象
		Socket s=ss.accept();
		//获取ip
		String ip=s.getInetAddress().getHostAddress();
		System.out.println(ip+"...connected");
		//获取socket对象读取流，并装饰
		BufferedReader br=new BufferedReader(new InputStreamReader(s.getInputStream()));
		//获取socket对象输出流
		PrintWriter out=new PrintWriter(s.getOutputStream(),true);
		String line=null;
		while((line=br.readLine())!=null){
			System.out.println(line);
			out.println(line.toUpperCase());
			out.flush();
		}
		br.close();
		out.close();
		s.close();
		ss.close();
	}

}

TransClient

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class TransClient {

	public static void main(String[] args) throws Exception {
		Socket s=new Socket("192.168.254.1",9999);
		//获取键盘录入
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		//获取socket输出流
		PrintWriter pw=new PrintWriter(s.getOutputStream(),true);
		//获取socket输入流  读取返回的大写数据
		BufferedReader br1=new BufferedReader(new InputStreamReader(s.getInputStream()));
		String line=null;
		while((line=br.readLine())!=null){
			//发送
			pw.println(line);
			pw.flush();
			//接收
			String str=br1.readLine();
			System.out.println(str);
		}
		s.close();
	}

}