后台任务 - 保持设备唤醒状态

代码中应用

package com.dn.ricky.performance.wake_lock;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.app.Service;
import android.app.job.JobInfo;
import android.app.job.JobScheduler;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.IBinder;
import android.os.PowerManager;
import android.support.v4.content.WakefulBroadcastReceiver;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.WindowManager;
import android.widget.TextView;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;

public class MainActivity extends AppCompatActivity {
    TextView wakelock_text;
    PowerManager pw;
    PowerManager.WakeLock mWakelock;
    private ComponentName serviceComponent;

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

        wakelock_text = (TextView) findViewById(R.id.wakelock_text);
        pw = (PowerManager) getSystemService(POWER_SERVICE);
        mWakelock = pw.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "mywakelock");
        serviceComponent = new ComponentName(this,MyJobService.class);
    }

    public void execut(View view) {
        wakelock_text.setText("正在下载....");
//        for (int i = 0; i < 500; i++) {
//            mWakelock.acquire();//唤醒CPU
//            wakelock_text.append(i+"连接中……");
////            wakelock_text.append("");
//            //下载
//            if (isNetWorkConnected()) {
//                new SimpleDownloadTask().execute();
//            } else {
//                wakelock_text.append("没有网络连接。");
//            }
//        }

        //优化
        JobScheduler jobScheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
        for (int i = 0; i < 500; i++) {
            JobInfo jobInfo = new JobInfo.Builder(i,serviceComponent)
                    .setMinimumLatency(5000)//5秒 最小延时、
                    .setOverrideDeadline(60000)//maximum最多执行时间
//                    .setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED)//免费的网络---wifi 蓝牙 USB
                    .setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY)//任意网络---wifi
                    .build();
            jobScheduler.schedule(jobInfo);
        }

    }

    private boolean isNetWorkConnected() {
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return (activeNetworkInfo != null && activeNetworkInfo.isConnected());
    }

    /**
     * Uses AsyncTask to create a task away from the main UI thread. This task creates a
     * HTTPUrlConnection, and then downloads the contents of the webpage as an InputStream.
     * The InputStream is then converted to a String, which is displayed in the UI by the
     * onPostExecute() method.
     */
    private static final String LOG_TAG = "ricky";
    private int index=0;

    private class SimpleDownloadTask extends AsyncTask {

        @Override
        protected String doInBackground(Void... params) {
            try {
                // Only display the first 50 characters of the retrieved web page content.
                int len = 50;
                try {
                    Thread.sleep(200);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
//                URL url = new URL("https://www.google.com");
                URL url = new URL("https://www.baidu.com");
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setReadTimeout(10000); // 10 seconds
                conn.setConnectTimeout(15000); // 15 seconds
                conn.setRequestMethod("GET");
                //Starts the query
                conn.connect();
                int response = conn.getResponseCode();
                index++;
                Log.d(LOG_TAG,  index+"The response is: " + response);
                InputStream is = conn.getInputStream();

                // Convert the input stream to a string
                Reader reader = new InputStreamReader(is, "UTF-8");
                char[] buffer = new char[len];
                reader.read(buffer);
                return new String(buffer);

            } catch (IOException e) {
                return "Unable to retrieve web page.";
            }
        }

        @Override
        protected void onPostExecute(String result) {
            wakelock_text.append("\n" + result + "\n");
            releaseWakeLock();
        }
    }

    private void releaseWakeLock() {
        if (mWakelock.isHeld()) {
            mWakelock.release();//记得释放CPU锁
            wakelock_text.append("释放锁！");
        }
    }

}

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.dn.ricky.performance.wake_lock;

import android.app.job.JobParameters;
import android.app.job.JobService;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.util.Log;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;

public class MyJobService extends JobService {
    private static final String LOG_TAG = "MyJobService";

    @Override
    public void onCreate() {
        super.onCreate();
        Log.i(LOG_TAG, "MyJobService created");
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i(LOG_TAG, "MyJobService destroyed");
    }

    @Override
    public boolean onStartJob(JobParameters params) {
        // This is where you would implement all of the logic for your job. Note that this runs
        // on the main thread, so you will want to use a separate thread for asynchronous work
        // (as we demonstrate below to establish a network connection).
        // If you use a separate thread, return true to indicate that you need a "reschedule" to
        // return to the job at some point in the future to finish processing the work. Otherwise,
        // return false when finished.
        Log.i(LOG_TAG, "Totally and completely working on job " + params.getJobId());
        // First, check the network, and then attempt to connect.
        if (isNetworkConnected()) {
            new SimpleDownloadTask() .execute(params);
            return true;
        } else {
            Log.i(LOG_TAG, "No connection on job " + params.getJobId() + "; sad face");
        }
        return false;
    }

    @Override
    public boolean onStopJob(JobParameters params) {
        // Called if the job must be stopped before jobFinished() has been called. This may
        // happen if the requirements are no longer being met, such as the user no longer
        // connecting to WiFi, or the device no longer being idle. Use this callback to resolve
        // anything that may cause your application to misbehave from the job being halted.
        // Return true if the job should be rescheduled based on the retry criteria specified
        // when the job was created or return false to drop the job. Regardless of the value
        // returned, your job must stop executing.
        Log.i(LOG_TAG, "Whelp, something changed, so I'm calling it on job " + params.getJobId());
        return false;
    }

    /**
     * Determines if the device is currently online.
     */
    private boolean isNetworkConnected() {
        ConnectivityManager connectivityManager =
                (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
        return (networkInfo != null && networkInfo.isConnected());
    }

    /**
     *  Uses AsyncTask to create a task away from the main UI thread. This task creates a
     *  HTTPUrlConnection, and then downloads the contents of the webpage as an InputStream.
     *  The InputStream is then converted to a String, which is logged by the
     *  onPostExecute() method.
     */
    private class SimpleDownloadTask extends AsyncTask {

        protected JobParameters mJobParam;

        @Override
        protected String doInBackground(JobParameters... params) {
            // cache system provided job requirements
            mJobParam = params[0];
            try {
                InputStream is = null;
                // Only display the first 50 characters of the retrieved web page content.
                int len = 50;

                URL url = new URL("https://www.google.com");
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setReadTimeout(10000); //10sec
                conn.setConnectTimeout(15000); //15sec
                conn.setRequestMethod("GET");
                //Starts the query
                conn.connect();
                int response = conn.getResponseCode();
                Log.d(LOG_TAG, "The response is: " + response);
                is = conn.getInputStream();

                // Convert the input stream to a string
                Reader reader = null;
                reader = new InputStreamReader(is, "UTF-8");
                char[] buffer = new char[len];
                reader.read(buffer);
                return new String(buffer);

            } catch (IOException e) {
                return "Unable to retrieve web page.";
            }
        }

        @Override
        protected void onPostExecute(String result) {
            jobFinished(mJobParam, false);
            Log.i(LOG_TAG, result);
        }
    }
}