Showing a null pointer exception in Android activity

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I have two java class where in the first activity i have created a database and stored some data in the sqlite DB. And in the second java class the data will be retrieved checking current date and time. but the second class is not starting. its showing a null pointer exception in the logcat. The first class is :

package com.example.eventmanager;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;

import com.example.eventmanager.R;

import android.app.Activity;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.TimePicker;
import android.widget.Toast;

public class MainActivity extends Activity {
    MediaPlayer mp;
    EditText name;
    EditText venue;
    public SQLiteDatabase eventsDB;

    private ScheduleClient scheduleClient;

    private DatePicker picker;

    private TimePicker timePic;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        scheduleClient = new ScheduleClient(this);
        scheduleClient.doBindService();

         picker = (DatePicker) findViewById(R.id.scheduleTimePicker);
         timePic = (TimePicker) findViewById(R.id.timePicer);
         name = (EditText) findViewById(R.id.ename);
         venue = (EditText) findViewById(R.id.venue);

    }

    public void onDateSelectedButtonClick(View v){

         eventsDB = this.openOrCreateDatabase("eventsDB", 0, null);
         eventsDB.setVersion(2);
         eventsDB.setLocale(Locale.getDefault());

         eventsDB.execSQL("CREATE TABLE IF NOT EXISTS " +
                 " events " +
                 " (name VARCHAR, date VARCHAR,time VARCHAR, venue VARCHAR);");

        int day = picker.getDayOfMonth();
        int month = picker.getMonth();
        int year = picker.getYear();
        Calendar c = Calendar.getInstance();
        c.set(year, month, day);
        c.set(Calendar.HOUR_OF_DAY, timePic.getCurrentHour());
        c.set(Calendar.MINUTE, timePic.getCurrentMinute());
        c.set(Calendar.SECOND, 0);

        String eday = String.valueOf(day);
        SimpleDateFormat month_date = new SimpleDateFormat("MMM"); // or "MMM" for short month name
        String emonth = month_date.format(c.getTime());

    //  String emonth = String.valueOf(month);
        String eyear = String.valueOf(year);
        String edate = eday+","+emonth+" "+eyear;

        String ehour = String.valueOf(timePic.getCurrentHour());
        String eminute = String.valueOf(timePic.getCurrentMinute());
        String etime = ehour+" : "+eminute;

        eventsDB.execSQL("INSERT INTO " +
                "events" +
                " Values ('"+name+"','"+edate+"','"+etime+"','"+venue+"');");

        scheduleClient.setAlarmForNotification(c);
        Toast.makeText(this, "The event for: "+ day +"/"+ (month+1) +"/"+ year+" Has been set", Toast.LENGTH_SHORT).show();

    }

    @Override
    protected void onStop() {
        if(scheduleClient != null)
            scheduleClient.doUnbindService();
        super.onStop();
    }

}

and the second class is:

package com.example.eventmanager;

import java.text.SimpleDateFormat;
import java.util.Calendar;

import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.TimePicker;

public class AlertActivity extends Activity {
    TextView test;
    public SQLiteDatabase eventsDB;
    private DatePicker picker;
    private TimePicker timePic;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.alert);

        test = (TextView) findViewById(R.id.textView1);

        Calendar c = Calendar.getInstance();
        int day = c.get(Calendar.DAY_OF_MONTH);

        //int month = c.get(Calendar.MONTH);
        SimpleDateFormat month_date = new SimpleDateFormat("MMM"); // or "MMM" for short month name
        String month = month_date.format(c.getTime());

        int year = c.get(Calendar.YEAR);

        String eday = String.valueOf(day);
        String emonth = String.valueOf(month);
        String eyear = String.valueOf(year);
        String edate = eday+","+emonth+" "+eyear;

        String ehour = String.valueOf(timePic.getCurrentHour());
        String eminute = String.valueOf(timePic.getCurrentMinute());
        String etime = ehour+" : "+eminute;

        String q="Select * from events where date='" + edate + "' and time='" + etime+ "'";

        Cursor m = eventsDB.rawQuery(q, null);

        if(edate.matches("") || etime.matches("") ){
            //Toast.makeText(getApplicationContext(), "Please insert a student ID", Toast.LENGTH_LONG).show();

        }
        else {
            if(m.moveToFirst() )
            {
            String curevent = m.getString(m.getColumnIndex("name"));
            String curdate = m.getString(m.getColumnIndex("edate"));

            test.setText(curevent);

            }
            else {
                test.setText("Not found");

            }
            }

    }

}

The logcat is here :

09-14 19:55:29.954: D/GalleryCacheReady(2754): Receive action.ACTION_MEDIA_SCANNER_FINISHED
09-14 19:55:29.959: E/AndroidRuntime(1266): FATAL EXCEPTION: main
09-14 19:55:29.959: E/AndroidRuntime(1266): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.eventmanager/com.example.eventmanager.AlertActivity}: java.lang.NullPointerException
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2125)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.ActivityThread.access$600(ActivityThread.java:140)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1227)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.os.Looper.loop(Looper.java:137)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.ActivityThread.main(ActivityThread.java:4898)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at java.lang.reflect.Method.invokeNative(Native Method)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at java.lang.reflect.Method.invoke(Method.java:511)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at dalvik.system.NativeStart.main(Native Method)
09-14 19:55:29.959: E/AndroidRuntime(1266): Caused by: java.lang.NullPointerException
09-14 19:55:29.959: E/AndroidRuntime(1266):     at com.example.eventmanager.AlertActivity.onCreate(AlertActivity.java:47)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.Activity.performCreate(Activity.java:5206)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1083)
09-14 19:55:29.959: E/AndroidRuntime(1266):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2064)
09-14 19:55:29.959: E/AndroidRuntime(1266):     ... 11 more
09-14 19:55:30.009: D/dalvikvm(1266): GC_CONCURRENT freed 204K, 6% free 13512K/14343K, paused 17ms+5ms, total 37ms

Please help me to find out the error as i am novice in android application development.

The problem is with String ehour = String.valueOf(timePic.getCurrentHour());, you never initialize timePic! Also, note that eventsDB is null too.

As per comments, you can get the hour with String ehour = String.valueOf(c.get(Calendar.HOUR); And minute with: String eminute = String.valueOf(c.get(Calendar.MINUTE);

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