HTTP网络请求图片

package com.example.day01_http_image01;

import android.annotation.SuppressLint;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
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.ImageView;
import android.widget.Toast;

import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

public class MainActivity extends AppCompatActivity {

    private EditText editText;
    private Button button;
    private ImageView imageView;
    private int timeout;
    private final int UPDATE_UI = 1;
    @SuppressLint("HandlerLeak")
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case UPDATE_UI:
                    imageView.setImageBitmap((Bitmap) msg.obj);
                    break;
            }
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取资源id
        editText = findViewById(R.id.ed_image);
        button = findViewById(R.id.btn_image);
        imageView = findViewById(R.id.image);
        //点击
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //判断是否有可用网络
                if(!NetUtil.hasNetwork(MainActivity.this)){
                    Toast.makeText(MainActivity.this,"当前网络不可用",Toast.LENGTH_LONG).show();
                    return;
                }
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        requestImage(editText.getText().toString());
                    }


                }).start();
            }

        });
    }
    private void requestImage(String image) {
        try {
            //定义URL地址
            URL url = new URL(image);
            //打开连接
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            //设置请求
            urlConnection.setRequestMethod("GET");
            //判断网络类型
            boolean phoneNetWork = NetUtil.isPhoneNetWork(MainActivity.this);
            if(phoneNetWork){
                timeout = 10000;
            }else{
                timeout = 5000;
            }
            //设置超时
            urlConnection.setReadTimeout(timeout);
            urlConnection.setConnectTimeout(timeout);
            //获取请求状态
            int responseCode = urlConnection.getResponseCode();
            if(responseCode == 200){
                Bitmap bitmap = BitmapFactory.decodeStream(urlConnection.getInputStream());
                handler.sendMessage(handler.obtainMessage(UPDATE_UI,bitmap));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

package com.example.day01_http_image01;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class NetUtil {
    //是否有可用网络
    public static boolean hasNetwork(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
        return activeNetworkInfo != null && activeNetworkInfo.isAvailable();
    }
    //判断是否是手机网络
    public static boolean isPhoneNetWork(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
        return activeNetworkInfo.getType() == ConnectivityManager.TYPE_MOBILE;
    }
}