我已经编写了一个用于创建和提醒任务的应用程序，该应用程序使用本地SqliteDatabase。 我编写了一个jobScheduler服务，用于检查数据库上任务的设备时间和日期，以及匹配是否显示推送通知。 我想要的也是服务在后台运行并每5秒检查一次数据。 但是当我写作
builder.setPeriodic（5000）; builder.setPersisted（真）;
服务停止检查数据。
这是我的代码
MainActivity
public class MainActivity extends AppCompatActivity {
ImageButton plusImageBtn;
DatabaseHelper databaseHelper;
BottomNavigationView navigation;
Toolbar toolbar;
private ComponentName mServiceComponent;
private int jobId=0;
private static final String TAG = MainActivity.class.getSimpleName();
public static final String WORK_DURATION_KEY =
BuildConfig.APPLICATION_ID + ".WORK_DURATION_KEY";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
navigation = (BottomNavigationView) findViewById(R.id.navigation);
plusImageBtn = (ImageButton) findViewById(R.id.plusImagBtn);
toolbar= (Toolbar) findViewById(R.id.toolbar_main);
setSupportActionBar(toolbar);
mServiceComponent = new ComponentName(this, JobSchedulerService.class);
databaseHelper= new DatabaseHelper(this);
navigation.setOnNavigationItemSelectedListener
(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
Fragment selectedFragment = null;
switch (item.getItemId()) {
case R.id.navigation_calendar:
selectedFragment = new CalendarFragment();
break;
case R.id.navigation_home:
selectedFragment = new ViewListContents();
break;
}
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_layout, selectedFragment);
transaction.commit();
return true;
}
});
FragmentTransaction transaction =
getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_layout,new ViewListContents());
transaction.commit();
scheduleJob();
}
@Override
protected void onStart() {
super.onStart();
// Start service and provide it a way to communicate with this class.
Intent startServiceIntent = new Intent(this, JobSchedulerService.class);
startService(startServiceIntent);
}
@Override
protected void onStop() {
stopService(new Intent(this,JobSchedulerService.class));
super.onStop();
}
public void scheduleJob() {
JobInfo.Builder builder = new JobInfo.Builder(jobId++, mServiceComponent);
// builder.setPeriodic(5000);
// builder.setPersisted(true);
builder.setMinimumLatency(1000);
builder.setOverrideDeadline(1000);
// Extras, work duration.
PersistableBundle extras = new PersistableBundle();
extras.putLong("",5000);
builder.setExtras(extras);
// Schedule job
Log.d(TAG, "Scheduling job");
JobScheduler tm = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
tm.schedule(builder.build());
Toast.makeText(this, "Scheduling job ", Toast.LENGTH_SHORT).show();
}}
JobSchedulerService
public class JobSchedulerService extends JobService {
int id;
String stringId;
String date;
String taskDate,taskTitle,taskTime,sepYear,sepMonth,
sepDay,convert,DeviceDate;
Cursor taskDateCursor;
DatabaseHelper databaseHelper;
Roozh roozh;
String[] seperatedString;
int iYear,iMonth, iDay;
SimpleDateFormat dateFormat, timeFormat;
private static final String TAG = JobSchedulerService.class.getSimpleName();
@Override
public void onCreate() {
super.onCreate();
Log.i(TAG, "Service created");
}
@Override
public void onDestroy() {
super.onDestroy();
Log.i(TAG, "Service destroyed"); }
@Override
public boolean onStartJob(final JobParameters params) {
stringId = String.valueOf(params.getJobId());
id = params.getJobId();
final long duration = params.getExtras().getLong(WORK_DURATION_KEY);
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
databaseHelper= new DatabaseHelper(getApplicationContext());
taskDateCursor=databaseHelper.getDateForNotification();
if (taskDateCursor.moveToFirst()){
do {
taskTitle=taskDateCursor.getString(taskDateCursor.getColumnIndex(DatabaseHelper.COL2));
taskDate=taskDateCursor.getString(taskDateCursor.getColumnIndex(DatabaseHelper.COL3));
taskTime=taskDateCursor.getString(taskDateCursor.getColumnIndex(DatabaseHelper.COL4));
roozh= new Roozh();
seperatedString=taskDate.split("/");
sepYear= seperatedString[0];
sepMonth= seperatedString[1];
sepDay= seperatedString[2].trim();
iYear= Integer.parseInt(sepYear);
iMonth= Integer.parseInt(sepMonth);
iDay= Integer.parseInt(sepDay);
roozh.PersianToGregorian(iYear,iMonth,iDay);
convert= roozh.toString();
dateFormat= new SimpleDateFormat(
"yyyy-MM-dd", Locale.getDefault());
DeviceDate= dateFormat.format(new Date());
timeFormat=new SimpleDateFormat("HH:m",Locale.getDefault());
String deviceTime=timeFormat.format(new Date());
RemoteViews remoteViews= new RemoteViews(getPackageName(),R.layout.notification);
remoteViews.setImageViewResource(R.id.notif_image, R.mipmap.ic_launcher);
remoteViews.setTextViewText(R.id.title,taskTitle);
remoteViews.setTextViewText(R.id.text,taskTime);
if (DeviceDate.equals(convert) && deviceTime.equals(taskTime) ){
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext())
.setSmallIcon(R.drawable.drawable_circle)
.setContent(remoteViews)
.setPriority(NotificationCompat.PRIORITY_DEFAULT)
.setColor(ContextCompat.getColor(getApplication(), R.color.primaryDarkColor))
.setShowWhen(true)
.setAutoCancel(true);
NotificationManagerCompat notificationManager = NotificationManagerCompat.from(getApplicationContext());
notificationManager.notify(0, mBuilder.build());
}
Log.i(TAG, "data " + DeviceDate+ "task" + convert+ " " + "dd" + " "+ taskTime + "dt" + "" + deviceTime);
}while (taskDateCursor.moveToNext());
} }
}, duration);
Log.i(TAG, "on start job: " + params.getJobId());
return true; }
@Override
public boolean onStopJob(JobParameters params) {
Log.i(TAG, "on stop job: " + params.getJobId());
return true; }
答案 0 :(得分：3)
setPeriodic（long intervalMillis）仅适用于低于Nougat的设备，对于具有Android版Nougat及以上版本的设备，使用此setPeriodic (long intervalMillis, long flexMillis)进行更改。
答案 1 :(得分：3)
我认为您的问题是您希望执行工作的频率。标准AOSP中的最短工作时间为15分钟。所以它可能不是适合您的API。警报管理器可能就是你想要的，但每隔5秒设置一次警报是很昂贵的。每次发布时，Google也越来越多地限制后台服务。请记住一些事情。
答案 2 :(得分：0)
ScheduledThreadPoolExecutor是一个更好的选择。 可以通过scheduleAtFixedRate或scheduleWithFixedDelay计划任务。
答案 3 :(得分：0)