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.IBinder; 22 23 /** 24 * <p>Entry point for the callback from the {@link android.app.job.JobScheduler}.</p> 25 * <p>This is the base class that handles asynchronous requests that were previously scheduled. You 26 * are responsible for overriding {@link JobService#onStartJob(JobParameters)}, which is where 27 * you will implement your job logic.</p> 28 * <p>This service executes each incoming job on a {@link android.os.Handler} running on your 29 * application's main thread. This means that you <b>must</b> offload your execution logic to 30 * another thread/handler/{@link android.os.AsyncTask} of your choosing. Not doing so will result 31 * in blocking any future callbacks from the JobManager - specifically 32 * {@link #onStopJob(android.app.job.JobParameters)}, which is meant to inform you that the 33 * scheduling requirements are no longer being met.</p> 34 * 35 * <p>As a subclass of {@link Service}, there will only be one active instance of any JobService 36 * subclasses, regardless of job ID. This means that if you schedule multiple jobs with different 37 * job IDs but using the same JobService class, that JobService may receive multiple calls to 38 * {@link #onStartJob(JobParameters)} and {@link #onStopJob(JobParameters)}, with each call being 39 * for the separate jobs.</p> 40 */ 41 public abstract class JobService extends Service { 42 private static final String TAG = "JobService"; 43 44 /** 45 * Job services must be protected with this permission: 46 * 47 * <pre class="prettyprint"> 48 * <service android:name="MyJobService" 49 * android:permission="android.permission.BIND_JOB_SERVICE" > 50 * ... 51 * </service> 52 * </pre> 53 * 54 * <p>If a job service is declared in the manifest but not protected with this 55 * permission, that service will be ignored by the system. 56 */ 57 public static final String PERMISSION_BIND = 58 "android.permission.BIND_JOB_SERVICE"; 59 60 private JobServiceEngine mEngine; 61 62 /** @hide */ onBind(Intent intent)63 public final IBinder onBind(Intent intent) { 64 if (mEngine == null) { 65 mEngine = new JobServiceEngine(this) { 66 @Override 67 public boolean onStartJob(JobParameters params) { 68 return JobService.this.onStartJob(params); 69 } 70 71 @Override 72 public boolean onStopJob(JobParameters params) { 73 return JobService.this.onStopJob(params); 74 } 75 }; 76 } 77 return mEngine.getBinder(); 78 } 79 80 /** 81 * Call this to inform the JobScheduler that the job has finished its work. When the 82 * system receives this message, it releases the wakelock being held for the job. 83 * This does not need to be called if {@link #onStopJob(JobParameters)} has been called. 84 * <p> 85 * You can request that the job be scheduled again by passing {@code true} as 86 * the <code>wantsReschedule</code> parameter. This will apply back-off policy 87 * for the job; this policy can be adjusted through the 88 * {@link android.app.job.JobInfo.Builder#setBackoffCriteria(long, int)} method 89 * when the job is originally scheduled. The job's initial 90 * requirements are preserved when jobs are rescheduled, regardless of backed-off 91 * policy. 92 * <p class="note"> 93 * A job running while the device is dozing will not be rescheduled with the normal back-off 94 * policy. Instead, the job will be re-added to the queue and executed again during 95 * a future idle maintenance window. 96 * </p> 97 * 98 * @param params The parameters identifying this job, as supplied to 99 * the job in the {@link #onStartJob(JobParameters)} callback. 100 * @param wantsReschedule {@code true} if this job should be rescheduled according 101 * to the back-off criteria specified when it was first scheduled; {@code false} 102 * otherwise. 103 */ jobFinished(JobParameters params, boolean wantsReschedule)104 public final void jobFinished(JobParameters params, boolean wantsReschedule) { 105 mEngine.jobFinished(params, wantsReschedule); 106 } 107 108 /** 109 * Called to indicate that the job has begun executing. Override this method with the 110 * logic for your job. Like all other component lifecycle callbacks, this method executes 111 * on your application's main thread. 112 * <p> 113 * Return {@code true} from this method if your job needs to continue running. If you 114 * do this, the job remains active until you call 115 * {@link #jobFinished(JobParameters, boolean)} to tell the system that it has completed 116 * its work, or until the job's required constraints are no longer satisfied. For 117 * example, if the job was scheduled using 118 * {@link JobInfo.Builder#setRequiresCharging(boolean) setRequiresCharging(true)}, 119 * it will be immediately halted by the system if the user unplugs the device from power, 120 * the job's {@link #onStopJob(JobParameters)} callback will be invoked, and the app 121 * will be expected to shut down all ongoing work connected with that job. 122 * <p> 123 * The system holds a wakelock on behalf of your app as long as your job is executing. 124 * This wakelock is acquired before this method is invoked, and is not released until either 125 * you call {@link #jobFinished(JobParameters, boolean)}, or after the system invokes 126 * {@link #onStopJob(JobParameters)} to notify your job that it is being shut down 127 * prematurely. 128 * <p> 129 * Returning {@code false} from this method means your job is already finished. The 130 * system's wakelock for the job will be released, and {@link #onStopJob(JobParameters)} 131 * will not be invoked. 132 * 133 * @param params Parameters specifying info about this job, including the optional 134 * extras configured with {@link JobInfo.Builder#setExtras(android.os.PersistableBundle)}. 135 * This object serves to identify this specific running job instance when calling 136 * {@link #jobFinished(JobParameters, boolean)}. 137 * @return {@code true} if your service will continue running, using a separate thread 138 * when appropriate. {@code false} means that this job has completed its work. 139 */ onStartJob(JobParameters params)140 public abstract boolean onStartJob(JobParameters params); 141 142 /** 143 * This method is called if the system has determined that you must stop execution of your job 144 * even before you've had a chance to call {@link #jobFinished(JobParameters, boolean)}. 145 * Once this method is called, you no longer need to call 146 * {@link #jobFinished(JobParameters, boolean)}. 147 * 148 * <p>This may happen if the requirements specified at schedule time are no longer met. For 149 * example you may have requested WiFi with 150 * {@link android.app.job.JobInfo.Builder#setRequiredNetworkType(int)}, yet while your 151 * job was executing the user toggled WiFi. Another example is if you had specified 152 * {@link android.app.job.JobInfo.Builder#setRequiresDeviceIdle(boolean)}, and the phone left 153 * its idle maintenance window. There are many other reasons a job can be stopped early besides 154 * constraints no longer being satisfied. {@link JobParameters#getStopReason()} will return the 155 * reason this method was called. You are solely responsible for the behavior of your 156 * application upon receipt of this message; your app will likely start to misbehave if you 157 * ignore it. 158 * <p> 159 * Once this method returns (or times out), the system releases the wakelock that it is holding 160 * on behalf of the job.</p> 161 * 162 * <p class="caution"><strong>Note:</strong> When a job is stopped and rescheduled via this 163 * method call, the deadline constraint is excluded from the rescheduled job's constraint set. 164 * The rescheduled job will run again once all remaining constraints are satisfied. 165 * 166 * @param params The parameters identifying this job, similar to what was supplied to the job in 167 * the {@link #onStartJob(JobParameters)} callback, but with the stop reason 168 * included. 169 * @return {@code true} to indicate to the JobManager whether you'd like to reschedule 170 * this job based on the retry criteria provided at job creation-time; or {@code false} 171 * to end the job entirely. Regardless of the value returned, your job must stop executing. 172 */ onStopJob(JobParameters params)173 public abstract boolean onStopJob(JobParameters params); 174 } 175