1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License
15  */
16 
17 package android.app.job;
18 
19 import android.app.Service;
20 import android.content.Intent;
21 import android.os.Handler;
22 import android.os.IBinder;
23 import android.os.Looper;
24 import android.os.Message;
25 import android.os.RemoteException;
26 import android.util.Log;
27 
28 import com.android.internal.annotations.GuardedBy;
29 
30 import java.lang.ref.WeakReference;
31 
32 /**
33  * <p>Entry point for the callback from the {@link android.app.job.JobScheduler}.</p>
34  * <p>This is the base class that handles asynchronous requests that were previously scheduled. You
35  * are responsible for overriding {@link JobService#onStartJob(JobParameters)}, which is where
36  * you will implement your job logic.</p>
37  * <p>This service executes each incoming job on a {@link android.os.Handler} running on your
38  * application's main thread. This means that you <b>must</b> offload your execution logic to
39  * another thread/handler/{@link android.os.AsyncTask} of your choosing. Not doing so will result
40  * in blocking any future callbacks from the JobManager - specifically
41  * {@link #onStopJob(android.app.job.JobParameters)}, which is meant to inform you that the
42  * scheduling requirements are no longer being met.</p>
43  */
44 public abstract class JobService extends Service {
45     private static final String TAG = "JobService";
46 
47     /**
48      * Job services must be protected with this permission:
49      *
50      * <pre class="prettyprint">
51      *     &#60;service android:name="MyJobService"
52      *              android:permission="android.permission.BIND_JOB_SERVICE" &#62;
53      *         ...
54      *     &#60;/service&#62;
55      * </pre>
56      *
57      * <p>If a job service is declared in the manifest but not protected with this
58      * permission, that service will be ignored by the OS.
59      */
60     public static final String PERMISSION_BIND =
61             "android.permission.BIND_JOB_SERVICE";
62 
63     private JobServiceEngine mEngine;
64 
65     /** @hide */
onBind(Intent intent)66     public final IBinder onBind(Intent intent) {
67         if (mEngine == null) {
68             mEngine = new JobServiceEngine(this) {
69                 @Override
70                 public boolean onStartJob(JobParameters params) {
71                     return JobService.this.onStartJob(params);
72                 }
73 
74                 @Override
75                 public boolean onStopJob(JobParameters params) {
76                     return JobService.this.onStopJob(params);
77                 }
78             };
79         }
80         return mEngine.getBinder();
81     }
82 
83     /**
84      * Override this method with the callback logic for your job. Any such logic needs to be
85      * performed on a separate thread, as this function is executed on your application's main
86      * thread.
87      *
88      * @param params Parameters specifying info about this job, including the extras bundle you
89      *               optionally provided at job-creation time.
90      * @return True if your service needs to process the work (on a separate thread). False if
91      * there's no more work to be done for this job.
92      */
onStartJob(JobParameters params)93     public abstract boolean onStartJob(JobParameters params);
94 
95     /**
96      * This method is called if the system has determined that you must stop execution of your job
97      * even before you've had a chance to call {@link #jobFinished(JobParameters, boolean)}.
98      *
99      * <p>This will happen if the requirements specified at schedule time are no longer met. For
100      * example you may have requested WiFi with
101      * {@link android.app.job.JobInfo.Builder#setRequiredNetworkType(int)}, yet while your
102      * job was executing the user toggled WiFi. Another example is if you had specified
103      * {@link android.app.job.JobInfo.Builder#setRequiresDeviceIdle(boolean)}, and the phone left its
104      * idle maintenance window. You are solely responsible for the behaviour of your application
105      * upon receipt of this message; your app will likely start to misbehave if you ignore it. One
106      * immediate repercussion is that the system will cease holding a wakelock for you.</p>
107      *
108      * @param params Parameters specifying info about this job.
109      * @return True to indicate to the JobManager whether you'd like to reschedule this job based
110      * on the retry criteria provided at job creation-time. False to drop the job. Regardless of
111      * the value returned, your job must stop executing.
112      */
onStopJob(JobParameters params)113     public abstract boolean onStopJob(JobParameters params);
114 
115     /**
116      * Call this to inform the JobManager you've finished executing. This can be called from any
117      * thread, as it will ultimately be run on your application's main thread. When the system
118      * receives this message it will release the wakelock being held.
119      * <p>
120      *     You can specify post-execution behaviour to the scheduler here with
121      *     <code>needsReschedule </code>. This will apply a back-off timer to your job based on
122      *     the default, or what was set with
123      *     {@link android.app.job.JobInfo.Builder#setBackoffCriteria(long, int)}. The original
124      *     requirements are always honoured even for a backed-off job. Note that a job running in
125      *     idle mode will not be backed-off. Instead what will happen is the job will be re-added
126      *     to the queue and re-executed within a future idle maintenance window.
127      * </p>
128      *
129      * @param params Parameters specifying system-provided info about this job, this was given to
130      *               your application in {@link #onStartJob(JobParameters)}.
131      * @param needsReschedule True if this job should be rescheduled according to the back-off
132      *                        criteria specified at schedule-time. False otherwise.
133      */
jobFinished(JobParameters params, boolean needsReschedule)134     public final void jobFinished(JobParameters params, boolean needsReschedule) {
135         mEngine.jobFinished(params, needsReschedule);
136     }
137 }