Using SharedPreferences to save variable makes my app crash

Question

I am using the SharedPreferences to save and get my variables to my app when the app closes or starts.

I am using the same type of method/code for all my variables and it works, except for one variable.

I think maybe the problem might be that this variable also is programmed to reset to = 0 at a specific time each day. (I am using BroadcastReceiver for this).

Since this is the only variable that I reset at a specific time, and the same variable crashes when I try to save it with SharedPreferences, there might be something about those two things that make my app angry.

  SharedPreferences settings2= getSharedPreferences(PREFS_NAME,0); 

Specifically this line of code below seems to crash the app

dosesTaken = settings2.getInt("dosesTaken",dosesTaken);

This is the class for the "BroadcastReciver"

import ...

public class AlarmResetTaken extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        MainActivity.dosesTaken = 0;
        MainActivity.setDosage();
        Activity2.takenDoseText.setText (Integer.toString(MainActivity.dosesTaken));
    }
}

This is the method in MainActivity for the "BroadcastReciver"

private void setAlarmResetDose(long timeInMillis) {
    AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(this, AlarmResetTaken.class);    
    PendingIntent pendingIntent = PendingIntent.getBroadcast(this,0,intent,0);    
    alarmManager.setRepeating(AlarmManager.RTC, timeInMillis, AlarmManager.INTERVAL_DAY, pendingIntent);
}

And the method for setting the specific time to reset.

public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
    timeDoseResetHour = hourOfDay;
    timeDoseResetMin = minute;    
    timeDoseResetText.setText( String.format("%02d",hourOfDay) +" : " + String.format("%02d",minute));

        Calendar calendar = Calendar.getInstance();
        calendar.set(
                calendar.get(Calendar.YEAR),
                calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH),
                hourOfDay,
                minute,
                0
        );
        setAlarmResetDose(calendar.getTimeInMillis()); }

This is the error i get:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.dex, PID: 28325
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.dex/com.example.dex.MainActivity}: java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
     Caused by: java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer
        at android.app.SharedPreferencesImpl.getInt(SharedPreferencesImpl.java:302)
        at com.example.dex.MainActivity.onCreate(MainActivity.java:92)
        at android.app.Activity.performCreate(Activity.java:7136)
        at android.app.Activity.performCreate(Activity.java:7127)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:193) 
        at android.app.ActivityThread.main(ActivityThread.java:6669) 

 

Answer 1

Was the type of dosesTaken of type long? If it was, chances are it is saved as a long and now you're trying to retrieve it as an int, which results in the ClassCastException. Try and clear your shared preferences and rerun the app.

Answer 2

From the error that you have posted,

java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer

it seems that, the type of dosesTaken is Long and not int. Thus, when you try to get an Integer with the name dosesTaken, it will throw an error.

Thus, to solve the error, either you change

settings2.getInt("dosesTaken",dosesTaken);

to

settings2.getLong("dosesTaken",dosesTaken);

OR

change the type of dosesTaken to int.

Answer 3

Change this -:

settings2.getInt("dosesTaken",dosesTaken);

to-:

settings2.getLong("dosesTaken",dosesTaken);