Java TCP ECHO服务器客户端[CODE]

秒速五厘米 2022-03-29 04:56 192阅读 0赞

EchoClient.java

import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.OutputStreamWriter;
    import java.io.PrintWriter;
    import java.net.Socket;
    import java.net.UnknownHostException;
    
    public class EchoClient {
        
    
    public static void main(String args[]){
        
            String hostname = "localhost";
    
    if(args.length > 0){
        
                hostname = args[0];
            }
    
    //定义一系列的变量
            PrintWriter  out = null;   //用于向网络写数据
            BufferedReader in = null;  //用于向网络读数据
            Socket socket = null;
            BufferedReader userIn = null; //用于获取键盘输入
            
    try {
        
    //实例化相应的变量
                socket = new Socket(hostname,9998);    
                in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
                userIn = new BufferedReader(new InputStreamReader(System.in));
    
                System.out.println("connect to echo Server" + hostname);
    
    while(true){
        
                    String theLine = userIn.readLine();
    if(theLine.equals(".")){
        
    break;
                    }
                    out.println(theLine);
                    System.out.println(in.readLine());
                }
            } catch (UnknownHostException e) {
        
    // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
        
    // TODO Auto-generated catch block
                e.printStackTrace();
            }
    
    try {
        
                in.close();
                socket.close();
            } catch (IOException e) {
        
    // TODO Auto-generated catch block
                e.printStackTrace();
            }
            out.close();
        }
    }

EchoServer.java

import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.OutputStreamWriter;
    import java.io.PrintWriter;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class EchoServer {
        
    
        @SuppressWarnings("null")
    public static void main(String args[]){
        
    
    //首先定义四个变量
            ServerSocket serversocket = null; //用于创建TCP服务器
            Socket socket = null;             //用于获得连接套接字
            BufferedReader in = null;   //用于接收数据
            PrintWriter out = null;           //用于发送数据
    //在网络编程中读取和发送相应的网络数据都需要自己的IO变量
            
    try {
        
    
                serversocket = new ServerSocket(9998);   //实例化监听套接字,绑定端口9998
                
    while(true){        
    //打印帮助消息
    //这里将会打印IP地址和端口相关的信息
                    System.out.println("The Server is start:" +serversocket);
    
    //等待客户端连接,连接成功之后,返回一个socket类型的变量,所有的数据传输都是和socket进行.    
    
                    socket = serversocket.accept();
    
    //打印客户端的相关消息
                    System.out.println("Accept the Client:" + socket);
    
    //实例化BufferedReader 对象用于接收客户端发送来的消息
    //InputStreamReader的作用是将字节流转换成为字符流
    //从网络中得到的数据将会存放在inBuffer变量当中
                    in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
    
    //得到输出流
                    out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
    
    //通过上面的工作,我对网络的读写操作都准备好了
                    while(true){
        
                        String instr  = in.readLine(); //按行读取数据
        
    if(instr == null){
        
    break; //当客户端关闭时跳出循环
                        }
    
                        System.out.println("In server received the info:" + instr);//打印获得的数据
                        out.println(instr);//将从网络中得到的数据回写
                    }
    
                }
            } catch (IOException e) {
        
    // TODO Auto-generated catch block
                e.printStackTrace();
            }
    
    try {
        
                socket.close();
                serversocket.close();
                in.close();
            } catch (IOException e) {
        
    // TODO Auto-generated catch block
                e.printStackTrace();
            }
            out.close();
            System.out.println("Server is exit");
        }
    }