1.联网权限

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

2.主界面网络下载

package com.example.glidedownload;import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;import com.bumptech.glide.Glide;
import com.bumptech.glide.load.engine.DiskCacheStrategy;
import com.bumptech.glide.request.animation.GlideAnimation;
import com.bumptech.glide.request.target.SimpleTarget;import java.io.File;
import java.util.Calendar;
import java.util.concurrent.ExecutionException;public class MainActivity extends AppCompatActivity implements View.OnClickListener {private Context mContext;private Button download;private ImageView img;private File target = null;// public static String PICTURE_s04 = "https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=339074543,1379749639&fm=26&gp=0.jpg";//   public static String PICTURE_04 = "https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=1774420118,989846740&fm=26&gp=0.jpg";public static String PIsCTURE_01 = "https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=1652123795,1945063222&fm=26&gp=0.jpg";public static String PIsssCTURE_01 = "https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=3574546774,2747680979&fm=11&gp=0.jpg";public static String PICTURE_01 = "https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=2807156066,2009521216&fm=11&gp=0.jpg";private String path;/*    private static final String URL ="https://uploadbeta.com/api/pictures/random/?key=BingEverydayWallpaperPicture";*/public static String FILENAME = Environment.getExternalStorageDirectory() + "/Download/picture.jpg";private static final String TAG = "MainActivity";private static final int REQUEST_EXTERNAL_STORAGE = 1;private static String[] PERMISSIONS_STORAGE = {Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mContext = this;download = findViewById(R.id.download);img = findViewById(R.id.img);target = new File(FILENAME);download.setOnClickListener(this);verifyStoragePermissions(this);if (target.exists()) {Glide.with(mContext).load(target).into(img);}}/*** 在对sd卡进行读写操作之前调用这个方法* Checks if the app has permission to write to device storage* If the app does not has permission then the user will be prompted to grant permissions*/public static void verifyStoragePermissions(Activity activity) {// Check if we have write permissionint permission = ActivityCompat.checkSelfPermission(activity,Manifest.permission.WRITE_EXTERNAL_STORAGE);if (permission != PackageManager.PERMISSION_GRANTED) {// We don't have permission so prompt the userActivityCompat.requestPermissions(activity, PERMISSIONS_STORAGE,REQUEST_EXTERNAL_STORAGE);}}@Overridepublic void onClick(View v) {if (v.getId() == R.id.download) {new Thread(new MyRunnable()).start();}}class MyRunnable implements Runnable {@Overridepublic void run() {downloadImage();getImageView();}}private void getImageView() {//  val saveAs = "Your_Created_Image_File_Path"Uri contentUri = Uri.fromFile(new File(path));Log.e(TAG, "onGetMessage_like: " + path);Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, contentUri);sendBroadcast(mediaScanIntent);}private String downloadImage() {Glide.get(getApplicationContext()).clearDiskCache();File file = null;try {file = Glide.with(mContext).load(PICTURE_01).downloadOnly(96, 96).get();} catch (Exception e) {e.printStackTrace();}path = FileUtil.copy(file, target);//    MediaStore.Images.Media.insertImage(getContentResolver(),.getPath(),"cameraPhoto", "Camera Pic Sample App Took");runOnUiThread(new Runnable() {@Overridepublic void run() {Glide.with(mContext).load(target).diskCacheStrategy(DiskCacheStrategy.NONE).skipMemoryCache(true).into(img);}});return path;}}

3.文件类

package com.example.glidedownload;import android.os.Environment;
import android.util.Log;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;/*** Created by zhc on 2019/12/19.*/
public class FileUtil {private static final String TAG = "FileUtil";/*** 复制文件* @param filename 文件名* @param bytes 数据*/public static void copy(String filename, byte[] bytes) {try {//如果手机已插入sd卡,且app具有读写sd卡的权限if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {FileOutputStream output = null;output = new FileOutputStream(filename);output.write(bytes);Log.i(TAG,"copy success, " + filename);output.close();} else {Log.i(TAG, "copy fail, " + filename);}} catch (IOException e) {e.printStackTrace();}}/*** 复制文件** @param source 输入文件* @param target 输出文件*/public static String copy(File source, File target) {FileInputStream fileInputStream = null;FileOutputStream fileOutputStream = null;try {fileInputStream = new FileInputStream(source);fileOutputStream = new FileOutputStream(target);byte[] buffer = new byte[1024];while (fileInputStream.read(buffer) > 0) {fileOutputStream.write(buffer);}} catch (Exception e) {e.printStackTrace();} finally {try {if (fileInputStream != null) {fileInputStream.close();}if (fileOutputStream != null) {fileOutputStream.close();}} catch (IOException e) {e.printStackTrace();}}return target.getPath();}}

4.打开相册，选择全部图片，可以看到刚刚下载的图片

end