一个ANDROID APP访问本机WEB URL的例子

 模拟机访问pc本机的webserver, 显示某一个页面的内容

需要在manifest里增加两条:

<uses-permission android:name="android.permission.INTERNET"/>

android:usesCleartextTraffic="true"

mainactivity的代码: 

package com.example.robotadmin;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    public String url_content  = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @SuppressLint("HandlerLeak")
    Handler handler=new Handler(){  //利用hander接收线程中发送的数据，并在UI界面中显示出来
        @Override
        public void handleMessage(Message msg) {
            if(msg.what==0x125){
//                imageView1.setImageBitmap(bitmap1);
                if (url_content == null){
                    System.out.println("zzt debug:  no result");

                  Toast.makeText(getApplicationContext(), "no result", Toast.LENGTH_SHORT).show();

                }
                else {
                    System.out.println("zzt debug: ");
                    System.out.println(url_content);

                    Toast.makeText(getApplicationContext(), url_content, Toast.LENGTH_SHORT).show();

                }
            }
        }
    };

    public void get_url(int i)
    {
        new Thread(){
            @Override
            public void run() {
                try {
                        //1、通过URL连接，读取网页中的内容
                        URL url = new URL("http://10.0.2."+ Integer.toString(2) +"/robotid.php");
                        //2、通过URL的openStream方法读取URL对象所定位的资源的字节流

                        HttpURLConnection htpcon = (HttpURLConnection) url.openConnection();
                        htpcon.setRequestMethod("GET");
                        htpcon.setDoOutput(true);
                        htpcon.setDoInput(true);
                        htpcon.setUseCaches(false);
                        htpcon.setConnectTimeout(1000);
                        htpcon.setReadTimeout(1000);
                        InputStream is = htpcon.getInputStream();

        //                InputStream is = url.openStream();
                        //3、将字节流转换成字符流
                        InputStreamReader isr = new InputStreamReader(is,"utf-8");
                        //4、将字符流添加一个缓冲区
                        BufferedReader br = new BufferedReader(isr);
                        //5、读取数据
                        String str = br.readLine();
                        while (str!=null){
                            System.out.println(str);
                            url_content = str;
                            str=br.readLine();
                        }
                        //6、把公共资源关闭
                        br.close();
                        is.close();
                        isr.close();
                } catch (Exception e) {
                    url_content = null;
                    e.printStackTrace();
                }
            }
        }.start();

    }


    public void onButton(View view) {
        new Thread(){
            @Override
            public void run() {
                get_url(2);
                handler.sendEmptyMessage(0x125);
            }
        }.start();
    }
}

本文地址：https://blog.csdn.net/andyzou221312/article/details/107405553