Android 基于TCP多线程通信实现群聊天的功能

1.TCP多线程原理图

2.实现方法

(1)服务器端

(2)客户端

3.java后台代码

主界面

package com.lucky.test50socket2;

import android.annotation.SuppressLint;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    EditText editText;
    TextView textView2;
    Button button1;
    ClientThread clientThread;

    //handler实现页面与Socket的交互,handler获取ClientThread中发送的message
    @SuppressLint("HandlerLeak")
    Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            if(msg.what==0x01){
                textView2.setText(msg.obj.toString());
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editText=findViewById(R.id.editText);
        textView2=findViewById(R.id.textView2);
        button1=findViewById(R.id.button);
        clientThread=new ClientThread(handler); //实例化ClientThread
        new Thread(clientThread).start();       //开启客户端的线程
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Message message=new Message(); //实例化一个message
                message.what=0x02; //设置message的代号
                message.obj=editText.getText().toString();//设置message的内容
                ClientThread.handlerrev.handleMessage(message); //调用ClientThread的成员对象的方法，向服务器发送消息
            }
        });

    }
}

服务器

package com.lucky.myserver;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

public class Myserver {
    public static List<Socket> list; //定义一个存放socket的集合
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket=new ServerSocket(30004); //实例化一个服务器套接字
        //while设置为死循环，等待客户端的socket请求的到来
        while (true){
            Socket socket=serverSocket.accept(); //获取套接字
            list=new ArrayList<>();
            list.add(socket);
            ServerThead serverThead=new ServerThead(socket); //调用自建的ServerThead
            new Thread(serverThead).start(); //启动线程
        }
    }
}

服务器线程

package com.lucky.myserver;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.Socket;

public class ServerThead implements Runnable {
    private Socket socket;
    InputStream inputStream;  //输入流
    OutputStream outputStream;//输出流
    BufferedReader bufferedReader;
    //构造方法
    public ServerThead(Socket socket) throws IOException {
        this.socket=socket;
        inputStream=socket.getInputStream(); //获取输入流
        bufferedReader=new BufferedReader(new InputStreamReader(inputStream,"utf-8"));

    }

    @Override
    public void run() {
        String str;
        while ((str=readData())!=null){
            for (Socket socket1 : Myserver.list) {
                try {
                    outputStream=socket1.getOutputStream();
                    PrintStream printStream=new PrintStream(outputStream);
                    printStream.println(socket.getInetAddress()+":"+str);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    private String readData(){
        try {
            return bufferedReader.readLine();
        } catch (IOException e) {
            Myserver.list.remove(socket); //删除套接字，避免占用内存
            return null;
        }
    }
}

客户端

package com.lucky.test50socket2;

import android.annotation.SuppressLint;
import android.os.Looper;
import android.os.Message;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.Socket;
import java.util.logging.Handler;

public class ClientThread implements Runnable {
    android.os.Handler handler1; //天坑：注意要导入android.os.Handler，handler要两种类型
    InputStream inputStream;
    OutputStream outputStream;
    BufferedReader bufferedReader;
    static android.os.Handler handlerrev;

    //构造方法
    public ClientThread(android.os.Handler handler){
        this.handler1=handler;
    }

    @SuppressLint("HandlerLeak")
    @Override
    public void run() {
        try {
            Socket socket=new Socket("192.168.228.2",30004); //连接服务器
            inputStream=socket.getInputStream();//实例化输入流
            bufferedReader=new BufferedReader(new InputStreamReader(inputStream,"GBK"));
            new Thread(){
                @Override
                public void run() {
                    String string;
                    try {
                        while ((string=bufferedReader.readLine())!=null){
                            Message message=new Message(); //实例化一个消息，通过handler发送到前台
                            message.what=0x01; //数据的代号
                            message.obj=string; //发送的数据
                            //信息回传给主线程（主界面）显示
                            handler1.sendMessage(message);
                        }
                    }catch (IOException e){
                        e.printStackTrace();
                    }
                }
            }.start();
            /*
             * 说明：如果要在非主线程中创建Handler对象，首先需要使用Looper类的prepare（）方法来初始化一个Looper对象，
             * 然后创建Handler对象，再使用Looper类的loop()方法启动Looper，从消息队列中获取和处理消息。
             */
            Looper.prepare(); //准备handler
            outputStream=socket.getOutputStream();//实例化输出流
            handlerrev=new android.os.Handler(){
                @Override
                public void handleMessage(Message msg) {
                    super.handleMessage(msg);
                    if(msg.what==0x02){  //根据msg是否是需要发送的消息，若是，执行以下操作
                        String str=msg.obj.toString();
                        PrintStream printStream=new PrintStream(outputStream);
                        printStream.println(str); //将消息数据发送到服务器
                    }
                }
            };
            Looper.loop(); //这句代码可以理解为循环执行run方法(最外层的run)
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}