请求网络下载图片

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

package com.example.net;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.ImageView;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class MainActivity extends Activity {

    Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            ImageView iv = (ImageView) findViewById(R.id.iv);
            iv.setImageBitmap((Bitmap)msg.obj);
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    public void click(View v) {
        new Thread() {
            @Override
            public void run() {

                //百度图片的地址
                String path = "http://192.168.0.101/news/images/image1.jpg";
                try {
                    URL url = new URL(path);
                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();

                    //设置请求的方法要大写
                    conn.setRequestMethod("GET");
                    conn.setReadTimeout(5000);
                    conn.setConnectTimeout(5000);
                    conn.connect();

                    if (conn.getResponseCode() == 200) {
                        InputStream is = conn.getInputStream();
                        Bitmap bm = BitmapFactory.decodeStream(is);
                        Message msg=handler.obtainMessage();
                        msg.obj=bm;
                        handler.sendMessage(msg);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }

            }
        }.start();

    }


}

---

布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <Button
        android:onClick="click"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="下载图片" />

    <ImageView
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"/>

</RelativeLayout>