java之客户端、服务端（Android）

安卓Socket客户端开发注意事项：
网络访问不能在主线程（UI线程）中进行，否则程序会崩溃
要创建线程来发起网络访问

服务端

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class test {
    public static void main(String[] args) {


        try {
            ServerSocket socket=new ServerSocket(8888);//创建套接字
            System.out.println("套接字创建成功，等待连接！");
            while(true){
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        int len=0;
                        byte[] a=new byte[128];
                        Socket con= null;
                        try {
                            con = socket.accept();//获取客户端连接
                            System.out.println("连接成功，等待接收");
                            InputStream inputStream = con.getInputStream();//获取输入流，用来读取数据
                            len=inputStream.read(a);

                            System.out.println("收到数据:"+new String(a,0,len));
                        } catch (IOException e) {
                            throw new RuntimeException(e);
                        }

                    }
                }).start();

            }


        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }
}

客户端

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.util.Scanner;

public class test {
    public static void main(String[] args) {
        try {
            int len=0;
            byte[] a=new byte[128];
            Socket client=new Socket("192.168.31.111",8800);
            Scanner sr=new Scanner(System.in);
            String str=sr.nextLine();
            OutputStream out =client.getOutputStream();//获取发送通道
            out.write(str.getBytes());//发送数据
            InputStream inputStream = client.getInputStream();//获取输入流，用来读取数据
            len=inputStream.read(a);

            System.out.println("收到数据:"+new String(a,0,len));

        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }
}

安卓代码

package com.example.myapplication;



import android.app.Activity;
import android.os.Bundle;

import android.view.View;

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;


public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }






    public  void send(View v) {

        switch (v.getId()) {
            case R.id.fowear:
                M1.m1("qianjin");
                break;
            case R.id.back:
                M1.m1("houtui");
                break;
            case R.id.turnlefe:
                M1.m1("xiangzhuo");
                break;
            case R.id.turnright:
                M1.m1("xiangyou");
                break;


        }
    }

}

M1代码

package com.example.myapplication;

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;

public class M1 {
    public static  void m1(String Data){
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Socket client = new Socket("192.168.31.151",8810);
                    OutputStream out =client.getOutputStream();//获取发送通道

                    out.write(Data.getBytes());//发送数据
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();



    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <Button
        android:id="@+id/fowear"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="148dp"
        android:layout_marginTop="176dp"
        android:onClick="send"
        android:text="前进"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/turnlefe"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="34dp"
        android:layout_marginTop="53dp"
        android:text="向左"
        android:onClick="send"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/fowear" />

    <Button
        android:id="@+id/turnright"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="30dp"
        android:layout_marginBottom="28dp"
        android:onClick="send"
        android:text="向右"
        app:layout_constraintBottom_toTopOf="@+id/back"
        app:layout_constraintEnd_toEndOf="parent" />

    <Button
        android:id="@+id/back"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="37dp"
        android:layout_marginTop="34dp"
        android:text="后退"
        android:onClick="send"
        app:layout_constraintStart_toEndOf="@+id/turnlefe"
        app:layout_constraintTop_toBottomOf="@+id/turnlefe" />

</androidx.constraintlayout.widget.ConstraintLayout>

注：使用网络都需加入权限