2019-08-20 Android下DownloadManager下载实现

https://www.cnblogs.com/zhaoyanjun/p/4591960.html

下载管理:
package com.tc.java.mvvmdagger.ui.activity.download.manager;

import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.util.Log;

import com.tc.java.mvvmdagger.ui.activity.download.listener.AndroidDownloadManagerListener;

import java.io.File;
import java.math.BigDecimal;

/**
 * 下载管理类:只负责下载
 */
public class AndroidDownloadManager {
    private DownloadManager downloadManager;
    private Context context;
    private long downloadId;
    private String url;
    private String name;

    private String path;

    private AndroidDownloadManagerListener listener;

    public AndroidDownloadManager(Context context, String url) {
        this(context, url, getFileNameByUrl(url));
    }

    public AndroidDownloadManager(Context context, String url, String name) {
        this.context = context;
        this.url = url;
        this.name = name;
    }

    public AndroidDownloadManager setListener(AndroidDownloadManagerListener listener) {
        this.listener = listener;
        return this;
    }

    /**
     * 开始下载
     */
    public void download() {
        DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
        //移动网络情况下是否允许漫游
        request.setAllowedOverRoaming(false);
        //在通知栏中显示,默认就是显示的
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
        request.setTitle(name);
        request.setDescription("文件正在下载中......");
        request.setVisibleInDownloadsUi(true);
        ///storage/emulated/0/Android/data/com.example.dell.mvvmdagger/files/Download/mobileqq_android.apk
        //设置下载的路径
        File file = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), name);
        request.setDestinationUri(Uri.fromFile(file));
        path = file.getAbsolutePath();

        //获取DownloadManager
        if (downloadManager == null) {
            downloadManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
        }
        //将下载请求加入下载队列,加入下载队列后会给该任务返回一个long型的id,通过该id可以取消任务,重启任务、获取下载的文件等等
        if (downloadManager != null) {
            if (listener != null) {
                listener.onPrepare();
            }
            downloadId = downloadManager.enqueue(request);
        }
        //IntentFilter filter=new IntentFilter();
        //filter.addAction("downloadAction");
        //注册广播接收者,监听下载状态
        //context.registerReceiver(receiver,filter);
        checkStatus();
    }


    private void checkStatus(){
         boolean isRuning=true;
        Intent intent=new Intent();
         while (isRuning){
             DownloadManager.Query query = new DownloadManager.Query();
             //通过下载的id查找
             query.setFilterById(downloadId);
             Cursor cursor = downloadManager.query(query);
             int[] bytesAndStatus = new int[]{
                     -1, -1, 0
             };
             if (cursor != null && cursor.moveToFirst()) {
                 int status = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
                 switch (status) {
                     //下载暂停
                     case DownloadManager.STATUS_PAUSED:
                         break;
                     //下载延迟
                     case DownloadManager.STATUS_PENDING:
                         break;
                     //正在下载
                     case DownloadManager.STATUS_RUNNING:
                         Log.i("gdchent", "下载中");
                         //已经下载文件大小
                         bytesAndStatus[0] = cursor.getInt(cursor.getColumnIndexOrThrow(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR));
                         //下载文件的总大小
                         bytesAndStatus[1] = cursor.getInt(cursor.getColumnIndexOrThrow(DownloadManager.COLUMN_TOTAL_SIZE_BYTES));
                         //下载状态
                         bytesAndStatus[2] = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
                         Log.i("gdchent", "下载文件的进度" + String.valueOf(bytesAndStatus[0]));

//                         intent.putExtra("data",bytesAndStatus[0]/bytesAndStatus[1]);
//                         intent.setAction("downloadAction");
//                         context.sendBroadcast(intent);
                         double dProgress=deciMal(bytesAndStatus[0],bytesAndStatus[1]);
                         if(listener!=null){
                             listener.onDownLoading((int) (dProgress*100));
                         }
                         break;
                     //下载完成
                     case DownloadManager.STATUS_SUCCESSFUL:
                         if (listener != null) {
                             listener.onSuccess(path);
                         }
                         cursor.close();
                         //context.unregisterReceiver(receiver);
                         isRuning=false ;
                         break;
                     //下载失败
                     case DownloadManager.STATUS_FAILED:
                         if (listener != null) {
                             listener.onFailed(new Exception("下载失败"));
                         }
                         cursor.close();
                         //context.unregisterReceiver(receiver);
                         isRuning=false ;
                         break;
                 }
             } else {
                 Log.i("gdchent", "走这里");
             }
         }
    }

    //广播监听下载的各个状态
//    private BroadcastReceiver receiver = new BroadcastReceiver() {
//        @Override
//        public void onReceive(Context context, Intent intent) {
//            Log.i("gdchent","onReceiver");
//            int num=intent.getIntExtra("data",-1);
//            Log.i("gdchent","num:"+String.valueOf(num));
//        }
//    };

    public String getName() {
        return name;
    }

    /**
     * 通过URL获取文件名
     *
     * @param url
     * @return
     */
    private static final String getFileNameByUrl(String url) {
        String filename = url.substring(url.lastIndexOf("/") + 1);
        filename = filename.substring(0, filename.indexOf("?") == -1 ? filename.length() : filename.indexOf("?"));
        return filename;
    }

    private double deciMal(int top, int below) {
        double result = new BigDecimal((float) top / below).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
        Log.i("返回的两位数", result + "'");
        return result;

    }
}

下载进度监听接口
package com.tc.java.mvvmdagger.ui.activity.download.listener;

/**
 * 下载监听
 */
public interface AndroidDownloadManagerListener {
    void onPrepare() ;//准备
    void onDownLoading(int progress);
    void onSuccess(String path) ; //下载成功
    void onFailed(Throwable throwable) ;//下载失败
}

下载的Activity示例:

package com.tc.java.mvvmdagger.ui.activity.download;

import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.support.v4.content.FileProvider;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import com.tc.java.mvvmdagger.BR;
import com.tc.java.mvvmdagger.R;
import com.tc.java.mvvmdagger.databinding.ActivityDownLoadManagerBinding;
import com.tc.java.mvvmdagger.rxjava.ComposerObserveable;
import com.tc.java.mvvmdagger.ui.activity.base.MvvmActivity;
import com.tc.java.mvvmdagger.ui.activity.download.listener.AndroidDownloadManagerListener;
import com.tc.java.mvvmdagger.ui.activity.download.manager.AndroidDownloadManager;
import com.tc.java.mvvmdagger.viewmodel.download.DownLoadManagerViewModel;
import com.trello.rxlifecycle2.components.support.RxAppCompatActivity;

import java.io.File;
import java.io.IOException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import io.reactivex.Observable;
import io.reactivex.ObservableEmitter;
import io.reactivex.ObservableOnSubscribe;
import io.reactivex.functions.Consumer;

public class DownLoadManagerActivity extends MvvmActivity<DownLoadManagerViewModel, ActivityDownLoadManagerBinding> {

    private String apkUrl = "https://qd.myapp.com/myapp/qqteam/AndroidQQ/mobileqq_android.apk";
    private AndroidDownloadManager androidDownloadManager;
    private ExecutorService fixedThreadPool;

    public DownLoadManagerActivity() {
        super(R.layout.activity_down_load_manager, new int[]{
                R.id.tv_down_load
        });
    }


    @Override
    protected void init() {
        binding.setVariable(BR.vm, VM);

    }

    @Override
    public void onClick(View v) {
        super.onClick(v);
        switch (v.getId()) {

            case R.id.tv_down_load: //点击下载
                androidDownloadManager = new AndroidDownloadManager(this, apkUrl)
                        .setListener(new AndroidDownloadManagerListener() {
                            @Override
                            public void onPrepare() {
                                Log.i("gdchent", "准备下载");
                            }

                            @Override
                            public void onSuccess(String path) {
                                Log.i("gdchent", "下载成功" + path);
                                installAPK(path);
                            }

                            @Override
                            public void onDownLoading(int progress) {
                                Log.i("gdchent","p:"+progress);
                                showProgress(progress);
                            }

                            @Override
                            public void onFailed(Throwable throwable) {
                                Log.i("gdchent", "faired" + throwable.getMessage());
                            }
                        });
                //创建一个可重用固定个数的线程池
                fixedThreadPool = Executors.newFixedThreadPool(3);
                Thread thread=new Thread(new Runnable() {
                    @Override
                    public void run() {
                        Log.i("gdchent","线程池执行");
                        androidDownloadManager.download();
                    }
                });
//                thread.start();
                fixedThreadPool.execute(thread);
                break;
        }
    }

    private void showProgress(int progress){
        ComposerObserveable composerObserveable=new ComposerObserveable();
        composerObserveable.wrapper((RxAppCompatActivity) context,Observable.just(progress))
                .subscribe(new Consumer() {
                    @Override
                    public void accept(Object result) throws Exception {
                        binding.progressHorizontal.setProgress((Integer) result);
                        binding.tvProgress.setText("下载进度:"+result);
                    }
                });
    }
   //安装apk
    private void installAPK(String pathstr) {
        setPermission(pathstr);
        Intent intent = new Intent(Intent.ACTION_VIEW);
        // 由于没有在Activity环境下启动Activity,设置下面的标签
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        //Android 7.0以上要使用FileProvider
        if (Build.VERSION.SDK_INT >= 24) {
            File file = (new File(pathstr));
            //参数1 上下文, 参数2 Provider主机地址 和配置文件中保持一致   参数3  共享的文件
            Uri apkUri = FileProvider.getUriForFile(context, getPackageName() + ".fileprovider", file);
            //添加这一句表示对目标应用临时授权该Uri所代表的文件
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            intent.setDataAndType(apkUri, "application/vnd.android.package-archive");
        } else {
            //new File(Environment.DIRECTORY_DOWNLOADS, androidDownloadManager.getName())
            String fileName = androidDownloadManager.getName();
            File file = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), fileName);
            intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");
        }
        startActivity(intent);
    }

    //修改文件权限
    private void setPermission(String absolutePath) {
        String command = "chmod " + "777" + " " + absolutePath;
        Runtime runtime = Runtime.getRuntime();
        try {
            runtime.exec(command);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        //关闭线程池
        fixedThreadPool.shutdown();
    }
}

要在AndroidManifest.xml文件中配置:

 <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="${applicationId}.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/filepath" />
        </provider>

然后在res下新建xml的目录下新建filepath.xml文件:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <paths>
        <external-path
            name="download"
            path="" />
    </paths>
</resources>

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