Hello i am learning android for some time, i want to make an app with more activities and one is a reminder, i have managed to clean the code of errors but when i run the app on phone and select that activity , it crashes, here is the log:
10-12 16:54:12.485 5364-5364/com.mihai_bucur.happycar E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.mihai_bucur.happycar, PID: 5364
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mihai_bucur.happycar/com.mihai_bucur.happycar.Documente}: java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.String android.content.SharedPreferences.getString(java.lang.String, java.lang.String)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2702)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2767)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1449)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5951)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.String android.content.SharedPreferences.getString(java.lang.String, java.lang.String)' on a null object reference
at com.mihai_bucur.happycar.RemindMe.getDateRange(RemindMe.java:51)
at com.mihai_bucur.happycar.Documente.onCreate(Documente.java:69)
at android.app.Activity.performCreate(Activity.java:6289)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2655)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2767)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1449)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5951)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
Also here is the activity that is related to crash:
RemindMe.java
package com.mihai_bucur.happycar;
import android.app.Application;
import android.content.SharedPreferences;
import android.database.sqlite.SQLiteDatabase;
import android.preference.PreferenceManager;
import com.mihai_bucur.happycar.model.DbHelper;
/**
* Created by Mihai on 03.10.2016.
*/
public class RemindMe extends Application {
// private static final String TAG = "RemindMe";
public static DbHelper dbHelper;
public static SQLiteDatabase db;
public static SharedPreferences sp;
public static final String TIME_OPTION = "time_option";
public static final String DATE_RANGE = "date_range";
public static final String DATE_FORMAT = "date_format";
public static final String TIME_FORMAT = "time_format";
public static final String VIBRATE_PREF = "vibrate_pref";
public static final String RINGTONE_PREF = "ringtone_pref";
public static final String DEFAULT_DATE_FORMAT = "yyyy-M-d";
@Override
public void onCreate() {
super.onCreate();
PreferenceManager.setDefaultValues(this, R.xml.setari, false);
sp = PreferenceManager.getDefaultSharedPreferences(this);
dbHelper = new DbHelper(this);
db = dbHelper.getWritableDatabase();
}
public static boolean showRemainingTime() {
return "1".equals(sp.getString(TIME_OPTION, "0"));
}
public static int getDateRange() {
return Integer.parseInt(sp.getString(DATE_RANGE, "0"));
}
public static String getDateFormat() {
return sp.getString(DATE_FORMAT, DEFAULT_DATE_FORMAT);
}
public static boolean is24Hours() {
return sp.getBoolean(TIME_FORMAT, true);
}
public static boolean isVibrate() {
return sp.getBoolean(VIBRATE_PREF, true);
}
public static String getRingtone() {
return sp.getString(RINGTONE_PREF, android.provider.Settings.System.DEFAULT_NOTIFICATION_URI.toString());
}
}
at the getDateRage line the error appears
and also appears on my main activity at on create method at "int r = RemindMe.getDateRange();"
Documente.java
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_documente);
findViews();
db = RemindMe.db;
/*font = Typeface.createFromAsset(getAssets(), "fonts/OpenSans-Semibold.ttf");*/
headingText.setTypeface(font);
monthArr = getResources().getStringArray(R.array.spinner3_arr);
int r = RemindMe.getDateRange();
can you help me to solve this ? :D, i have searched on the internet but i was not able to find a solution and make it work Thanks!
