servicebestpractice项目的更新

package com.example.servicebestpractice;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.notificationmanager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.os.Binder;
import android.os.Build;
import android.os.Environment;
import android.os.IBinder;
import android.webkit.DownloadListener;
import android.widget.TextView;
import android.widget.Toast;

import java.io.File;

import androidx.annotation.Nullable;
import androidx.core.app.NotificationCompat;

public class DownloadService extends Service {
    private DownloadTask downloadTask;
    private String downloadUrl;
    private IDownloadListener listener = new IDownloadListener() {
        @Override
        public void onProgress(int progress) {
            getnotificationmanager().notify(1, getNotification("Downloading...", progress));
        }

        @Override
        public void onSuccess() {
            downloadTask = null;
            //下载成功时将前台服务关闭，并创建一个下载成功的通知
            stopForeground(true);
            getnotificationmanager().notify(1, getNotification("Download Success", -1));
            Toast.makeText(DownloadService.this, "Download Success", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onFailed() {
            downloadTask = null;
            // 下载失败时将前台服务通知关闭，并创建一个下载失败的通知
            downloadTask = null;
            stopForeground(true);
            getnotificationmanager().notify(1,getNotification("Download Failed",-1));
            Toast.makeText(DownloadService.this,"Download Failed",Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onPaused() {
            downloadTask = null;
            stopForeground(true);
            Toast.makeText(DownloadService.this,"Paused",Toast.LENGTH_SHORT).show();

        }

        @Override
        public void onCanceled() {
            downloadTask = null;
            stopForeground(true);
            Toast.makeText(DownloadService.this,"Canceled",Toast.LENGTH_SHORT).show();

        }
    };

   private DownloadBinder mBinder = new DownloadBinder();

    @Override
    public IBinder onBind(Intent intent) {
        return mBinder;
    }
    public class DownloadBinder extends Binder {
        public void startDownload(String url){
            if(downloadTask==null){
                downloadUrl = url;
                downloadTask = new DownloadTask(listener);
                downloadTask.execute(downloadUrl);
                startForeground(1,getNotification("Downloading...",0));
                Toast.makeText(DownloadService.this,"Downloading...",Toast.LENGTH_SHORT).show();
            }

        }
        public void pauseDownload(){
            if(downloadTask!=null){
                downloadTask.pauseDownload();
            }

        }
        public void cancelDownload(){
            if(downloadTask!=null){
                downloadTask.cancelDownload();
            }else{
                if(downloadUrl!=null){
                    //取消下载时删除文件，并通知关闭
                    String fileName = downloadUrl.substring(downloadUrl.lastIndexOf("/"));
                    String directory = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath();
                    File file = new File(directory+fileName);
                    if(file.exists()){
                        file.delete();
                    }
                    getnotificationmanager().cancel(1);
                    stopForeground(true);
                    Toast.makeText(DownloadService.this,"Canceled",Toast.LENGTH_SHORT).show();
                }
            }

        }

    }

    private notificationmanager getnotificationmanager() {
        return (notificationmanager) getSystemService(NOTIFICATION_SERVICE);
    }
    private Notification getNotification(String title, int progress) {
        Intent intent = new Intent(this, MainActivity.class);
        PendingIntent pi = PendingIntent.getActivity(this, 0, intent, 0);

        notificationmanager manager=(notificationmanager)getSystemService(NOTIFICATION_SERVICE);


        if(Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O){
            //只在Android O之上需要渠道，这里的第一个参数要和下面的channelId一样
            NotificationChannel notificationChannel = new NotificationChannel("download","name",notificationmanager.IMPORTANCE_HIGH);
            //如果这里用IMPORTANCE_NOENE就需要在系统的设置里面开启渠道，通知才能正常弹出
            manager.createNotificationChannel(notificationChannel);
        }



        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, "download");
        builder.setSmallIcon(R.mipmap.ic_launcher);
        builder.setLargeIcon(BitmapFactory.decodeResource(getResources(),
                R.mipmap.ic_launcher));
        builder.setContentIntent(pi);
        builder.setContentTitle(title);
        if (progress > 0) {
            //大于0开始显示进度
            builder.setContentText(progress + "%");
            builder.setProgress(100, progress, false);
        }
        return builder.build();
    }


}