android複習路之service綜合篇

android中service和Asnyctask沒有寫過綜合應用，最近也在看東西沒有段時間發過博文了。今天發表一個綜合應用記錄，代碼是來源於郭神的第一行代碼，自己進行分析，算事研讀吧。要知道的都在註釋裏。這是一個下載文件的demo並且在系統通知欄顯示。

activity：

package com.example.zobject.http;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.content.pm.PackageManager;
import android.os.IBinder;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.jar.Manifest;

import okhttp3.Call;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
        private MyService.DownLoadBinder downLoadBinder;//首先獲得DownLoadBinder的實例



        private ServiceConnection connection =new ServiceConnection() { //實現ServiceConnection內部類就可以在activity中調用 service中的方法了
            @Override
            public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
                downLoadBinder= (MyService.DownLoadBinder) iBinder;
            }

            @Override
            public void onServiceDisconnected(ComponentName componentName) {

            }
        };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button button = (Button) findViewById(R.id.strat);
        Button button1 = (Button) findViewById(R.id.pause);
        Button button2 = (Button) findViewById(R.id.cancel);
        button.setOnClickListener(this);
        button1.setOnClickListener(this);
        button2.setOnClickListener(this);
        Intent intent =new Intent(this,MyService.class);
        startService(intent);//啓動服務
        bindService(intent,connection,BIND_AUTO_CREATE);//綁定服務
        if (ContextCompat.checkSelfPermission(MainActivity.this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED){//權限檢查
            ActivityCompat.requestPermissions(MainActivity.this,new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
        }
    }


    @Override
    public void onClick(View view) {//三種方法的調用
        if (downLoadBinder==null){
            return;
        }
        switch (view.getId()){
            case  R.id.strat:
                String url="https://raw.githubusercontent.com/guolindev/eclipse/master/eclipse-inst-win64.exe";
                downLoadBinder.startDownload(url);
                break;
            case R.id.pause:
                downLoadBinder.PauseDownload();
                break;
            case R.id.cancel:
                downLoadBinder.cancelDownload();
                break;

        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {//如果沒有權限輸出拒絕
        switch (requestCode){
            case 1:
                if (grantResults.length>0&&grantResults[0]!=PackageManager.PERMISSION_GRANTED){
                    Toast.makeText(this,"ju",Toast.LENGTH_LONG);
                }
                break;
            default:
        }



    }

    @Override
    protected void onDestroy() {//在activity銷燬的時候解綁service 因爲在service還在運行會造成內存泄露
        super.onDestroy();
        unbindService(connection);
    }
}

listener接口

public interface DownLoadListener {  // service和底層的通行接口
    void onProgess(int progess);
    void Success();
    void Failed();
    void onPaused();
    void onCanceled();

}

service層：

package com.example.zobject.http;

import android.app.Notification;
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.Environment;
import android.os.IBinder;
import android.support.v4.app.NotificationCompat;
import android.widget.Toast;

import java.io.File;

public class MyService extends Service {

    private String downloadUrl;
    private DownLoad downLoad;
    private DownLoadListener downLoadListener = new DownLoadListener() {//實現定義的接口
        @Override
        public void onProgess(int progess) {
            getNoti().notify(1, notification("Download.......", progess));
        }

        @Override
        public void Success() {
            downLoad = null;
            stopForeground(true);//把進程放到前臺進行避免被殺掉
            getNoti().notify(1, notification("DownSuccess", -1));
            Toast.makeText(MyService.this, "Successs", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void Failed() {
            downLoad = null;
            stopForeground(true);
            getNoti().notify(1, notification("DownloadFailed", -1));
            Toast.makeText(MyService.this, "Failed", Toast.LENGTH_LONG).show();
        }

        @Override
        public void onPaused() {
            downLoad = null;
            Toast.makeText(MyService.this, "Pause", Toast.LENGTH_LONG).show();
        }

        @Override
        public void onCanceled() {
            downLoad = null;
            stopForeground(true);
            Toast.makeText(MyService.this, "Cancelded", Toast.LENGTH_LONG).show();
        }
    };




    private NotificationManager getNoti() {//進行進度條的顯示和定義
        return (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
    }

    private Notification notification(String title, int progess) {
        Intent intent = new Intent(this, MainActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
        builder.setSmallIcon(R.mipmap.ic_launcher);
        builder.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher));
        builder.setContentIntent(pendingIntent);
        builder.setContentTitle(title);
        if (progess > 0) {
            builder.setContentText(progess + "%");
            builder.setProgress(100, progess, false);
        }
        return builder.build();
    }

    private DownLoadBinder downLoadBind = new DownLoadBinder();

    @Override
    public IBinder onBind(Intent intent) {
        return downLoadBind;
    }

    class DownLoadBinder extends Binder {//繼承binder 供上層進行調用

        public void startDownload(String url) {
            if (downLoad == null) {
                downloadUrl = url;
                downLoad = new DownLoad(downLoadListener);//綁定一個listener給底層方便調用
                startForeground(1, notification("download.......", 0));
                downLoad.execute(downloadUrl);//在這開啓ansyctask的異步調用
                Toast.makeText(MyService.this, "startdownload........", Toast.LENGTH_LONG).show();

            }
        }

        public void PauseDownload() {
            if (downLoad != null) {
                downLoad.pauseDown();
            }
        }

        public void cancelDownload() {
            if (downLoad != null) {// 這個是下載直接停止
                downLoad.canelDown();
            } else {
                if (downloadUrl != null) {// 這部分是暫停後取消
                    String fileName = downloadUrl.substring(downloadUrl.lastIndexOf("/"));
                    String dectoty = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath();
                    File file = new File(dectoty + fileName);
                    if (file.exists()) {
                        file.exists();
                    }
                    getNoti().cancel(1);
                    stopForeground(true);
                    Toast.makeText(MyService.this, "Canceled", Toast.LENGTH_LONG).show();
                }
            }
        }
    }
}

Asyn:

package com.example.zobject.http;

import android.os.AsyncTask;
import android.os.Environment;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

/**
 * Created by zobject on 2017/1/11.
 */

public class DownLoad extends AsyncTask<String, Integer, Integer> {///異步處理接受三個參數第一個是url地址，第二個和第三個進度反饋用int型
    public static final int SUCCESS = 0;
    public static final int FAILED = 1;
    public static final int PAUSEE = 2;
    public static final int CANCELED = 3;
    private DownLoadListener downLoadListener;
    private boolean isCancelde = false;
    private boolean isPause = false;
    private int lastProgess;

    public DownLoad(DownLoadListener listener) {
        this.downLoadListener = listener;
    }//接受一個接受進來

    @Override
    protected Integer doInBackground(String... strings) {//接受 第一個參數進來
        InputStream inputStream = null;
        RandomAccessFile saveFile = null;//隨機存儲方法
        File file = null;
        try {
            long DownLoadLength = 0;
            String downLoadUrl = strings[0];
            String fileName = downLoadUrl.substring(downLoadUrl.lastIndexOf("/"));//通過路徑獲得到文件的名字
            String directory = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getPath();//獲取到downloadd的文件路徑
            file = new File(directory + fileName);//文件的路徑爲file
            if (file.exists()) {
                DownLoadLength = file.length();//判讀路徑是否存在，下載的長度文件的文件的當前長度，這個段代碼用來讀取當前的下載數目，用來實現暫停後繼續下載
            }

            long ContentLength = getContentLength(downLoadUrl);//求的文件的總的長度
            if (ContentLength == 0) {
                return FAILED;
            } else if (ContentLength == DownLoadLength) {
                return SUCCESS;
            }
            OkHttpClient okhettp = new OkHttpClient();//這裏是繼續下載的操作
            Request requset = new Request.Builder().addHeader("RANGE", "bytes" + DownLoadLength + "-").url(downLoadUrl).build();//跳過下載過的文件

            Response response = okhettp.newCall(requset).execute();
            if (response != null) {//這段就是存儲下載好的文件了，如果返回的不是空值就進行存儲

                inputStream = response.body().byteStream();
                saveFile = new RandomAccessFile(file, "rw");
                saveFile.seek(DownLoadLength);
                byte[] b = new byte[1024];
                int total = 0;
                int len;
                while ((len = inputStream.read()) != -1) {
                    if (isCancelde) {
                        return CANCELED;//如果前臺進行了取消操作就返回取消的標識符
                    } else if (isPause) {
                        return PAUSEE;//如果前臺返進行了暫停就返回暫停的標識符
                    } else {
                        total += len;
                        saveFile.write(b, 0, len);
                        int progess = (int) ((total + DownLoadLength) * 100 / ContentLength);//這裏就是下載進度的實時反饋
                        publishProgress(progess);//切換到主線程進行京進度條的加載
                    }
                }
                response.body().close();//下載完成
                return SUCCESS;
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null) {
                    inputStream.close();

                }
                if (saveFile != null) {
                    saveFile.close();
                }
                if (isCancelde && file != null) {
                    file.delete();//如果取消了下載，就刪除文件
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

        return FAILED;
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        int progress = values[0];
        if (progress > lastProgess) {
            downLoadListener.onProgess(progress);//實時的反饋下砸進度
            lastProgess = progress;
        }
    }

    @Override
    protected void onPostExecute(Integer integer) {//四種結果的反饋結果提供給藉口進行回掉
        switch (integer) {
            case SUCCESS:
                downLoadListener.Success();
                break;
            case FAILED:
                downLoadListener.Failed();
                break;
            case PAUSEE:
                downLoadListener.onPaused();
                break;
            case CANCELED:
                downLoadListener.onCanceled();
                break;
            default:
                break;

        }
    }

    public void pauseDown() {
        isPause = true;
    }//提供給服務層進行調用讓本層進行一定的操作

    public void canelDown() {
        isCancelde = true;
    }

    private long getContentLength(String downLoadUrl) throws IOException {//返回文件的長度顯示計算的百分比
        OkHttpClient client = new OkHttpClient();
        Request requset = new Request.Builder().url(downLoadUrl).build();
        Response res = client.newCall(requset).execute();
        if (res != null && res.isSuccessful()) {
            long reslength = res.body().contentLength();
            res.close();
            return reslength;
        }
        return 0;
    }
}

效果圖：

android複習路之service綜合篇

HTTP URL 詳解

android複習路之RecyclerView簡單的應用

android複習路之java虛擬機

android複習路之內存泄漏篇

android複習路之不死的service

android複習路之Service篇

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

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