Java TCP 两台电脑交互

客户端代码

import java.io.*;
import java.net.*;


public class SingleTalkClient
{
    public static void main(String[] args) throws IOException
{


        Socket client = null;//客户端的socket对象
        PrintWriter out = null;//PrintWriter extends Writer向文本输出流打印对象的格式化表示形式
        BufferedReader in = null; // BufferdReader extends Reader
        //从字符输入流中读取文本，缓冲各个字符，从而提供字符、数组和行的高效读取。


        try {
            client = new Socket("？？？", 4444);//InteAddress,port  （???是服务端计算机的IP）
            out = new PrintWriter(client.getOutputStream(), true); //auto flush自动刷新
            //getOutputStream()得到对应的输出流，返回OutputStream对象
            in = new BufferedReader(new InputStreamReader(client.getInputStream()));
            
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: 127.0.0.1.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to: 127.0.0.1.");
            System.exit(1);
        }


        //从标准输入流（键盘）中获取信息//由系统标准输入设备构造缓冲输入流
BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
        
String fromServer, fromUser;
boolean sbye = false;
boolean ubye = false;


System.out.print("Client input:");
fromUser = stdIn.readLine();//系统标准输入流读入一串字符
        while( true )  
{
if( ubye == false )
{
out.println(fromUser);
out.flush();//清空输出流
//System.out.println("Client: " + fromUser);
if (fromUser.equals("Bye."))
ubye = true;
}


if( sbye == false )
{
fromServer = in.readLine();//标准输入流中读入数据
System.out.println("from Server: " + fromServer);
if (fromServer.equals("Bye."))
sbye = true;
}


if( ubye == false )
{
System.out.print("Client input:");
fromUser = stdIn.readLine();
}


if( ubye == true && sbye == true )
break;
        }


        out.close();
        in.close();
        stdIn.close();
        client.close();
    }
}

服务端代码

import java.net.*;
import java.io.*;


public class SingleTalkServer
{
    public static void main(String[] args) throws IOException
{


        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(4444);//port，创建一个在端口4444监听客户请求的serverSocket
        } catch (IOException e) {
            System.err.println("Could not listen on port: 4444.");
            System.exit(1);
        }


        Socket clientSocket = null;
        try {
            clientSocket = serverSocket.accept();  //程序将在此等候客户端的连接
        } catch (IOException e) {
            System.err.println("Accept failed.");
            System.exit(1);
        }
System.out.println("Accept OK!");


        //打开输入/输出流
PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);  //由stock对象得到文本输出流auto flush
    BufferedReader in = new BufferedReader(new  //由stock对象得到缓冲输入流
    InputStreamReader(clientSocket.getInputStream()));


//从标准输入流（键盘）中获取信息//由系统标准输入设备构造缓冲输入流
    BufferedReader sin = new BufferedReader( new InputStreamReader( System.in ) ); 
        


boolean  sinbye = false;
boolean  inbye = false;
String sinputLine, inputLine;
        
    inputLine = in.readLine();
System.out.println( "from Client: " + inputLine );


System.out.print("Server input:");
sinputLine = sin.readLine();//系统标准输入流读入一串字符


        while( true )
{
if( sinbye == false )
{
out.println(sinputLine);//文本输出流写入数据
out.flush();
//System.out.println("Server: " + sinputLine);


if (sinputLine.equals("Bye."))
sinbye = true;
}


if( inbye == false )
{
inputLine = in.readLine();//缓冲输入流读入数据
System.out.println( "from Client: " + inputLine );


if (inputLine.equals("Bye."))
inbye = true;
}


if( sinbye == false )
{
System.out.print("Server input:");
sinputLine = sin.readLine();//标准输入流读入数据
}


if( sinbye == true && inbye == true )
break;
        }


        out.close();
        in.close();
        sin.close();
        clientSocket.close();
        serverSocket.close();
    }
}