Unfortunately appl has stopped

[emalu483]

Aiuto, non riesco a risolvere questo problema che mi stoppa il problema, vi posto il log cat:

04-23 19:54:53.894: E/AndroidRuntime(531): FATAL EXCEPTION: main
04-23 19:54:53.894: E/AndroidRuntime(531): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rubrica/com.example.rubrica.SqlView}: java.lang.NullPointerException
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.ActivityThread.access$600(ActivityThread.java:123)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.os.Handler.dispatchMessage(Handler.java:99)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.os.Looper.loop(Looper.java:137)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.ActivityThread.main(ActivityThread.java:4424)
04-23 19:54:53.894: E/AndroidRuntime(531): at java.lang.reflect.Method.invokeNative(Native Method)
04-23 19:54:53.894: E/AndroidRuntime(531): at java.lang.reflect.Method.invoke(Method.java:511)
04-23 19:54:53.894: E/AndroidRuntime(531): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
04-23 19:54:53.894: E/AndroidRuntime(531): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
04-23 19:54:53.894: E/AndroidRuntime(531): at dalvik.system.NativeStart.main(Native Method)
04-23 19:54:53.894: E/AndroidRuntime(531): Caused by: java.lang.NullPointerException
04-23 19:54:53.894: E/AndroidRuntime(531): at com.example.rubrica.Persona.getData(Persona.java:72)
04-23 19:54:53.894: E/AndroidRuntime(531): at com.example.rubrica.SqlView.onCreate(SqlView.java:16)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.Activity.performCreate(Activity.java:4465)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
04-23 19:54:53.894: E/AndroidRuntime(531): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
04-23 19:54:53.894: E/AndroidRuntime(531): ... 11 more
04-23 20:14:01.555: E/AndroidRuntime(582): FATAL EXCEPTION: main
04-23 20:14:01.555: E/AndroidRuntime(582): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rubrica/com.example.rubrica.SqlView}: java.lang.NullPointerException
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.ActivityThread.access$600(ActivityThread.java:123)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.os.Handler.dispatchMessage(Handler.java:99)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.os.Looper.loop(Looper.java:137)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.ActivityThread.main(ActivityThread.java:4424)
04-23 20:14:01.555: E/AndroidRuntime(582): at java.lang.reflect.Method.invokeNative(Native Method)
04-23 20:14:01.555: E/AndroidRuntime(582): at java.lang.reflect.Method.invoke(Method.java:511)
04-23 20:14:01.555: E/AndroidRuntime(582): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
04-23 20:14:01.555: E/AndroidRuntime(582): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
04-23 20:14:01.555: E/AndroidRuntime(582): at dalvik.system.NativeStart.main(Native Method)
04-23 20:14:01.555: E/AndroidRuntime(582): Caused by: java.lang.NullPointerException
04-23 20:14:01.555: E/AndroidRuntime(582): at com.example.rubrica.Persona.getData(Persona.java:72)
04-23 20:14:01.555: E/AndroidRuntime(582): at com.example.rubrica.SqlView.onCreate(SqlView.java:16)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.Activity.performCreate(Activity.java:4465)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
04-23 20:14:01.555: E/AndroidRuntime(582): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
04-23 20:14:01.555: E/AndroidRuntime(582): ... 11 more
04-23 20:17:43.895: E/AndroidRuntime(598): FATAL EXCEPTION: main
04-23 20:17:43.895: E/AndroidRuntime(598): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rubrica/com.example.rubrica.SqlView}: java.lang.NullPointerException
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.ActivityThread.access$600(ActivityThread.java:123)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.os.Handler.dispatchMessage(Handler.java:99)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.os.Looper.loop(Looper.java:137)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.ActivityThread.main(ActivityThread.java:4424)
04-23 20:17:43.895: E/AndroidRuntime(598): at java.lang.reflect.Method.invokeNative(Native Method)
04-23 20:17:43.895: E/AndroidRuntime(598): at java.lang.reflect.Method.invoke(Method.java:511)
04-23 20:17:43.895: E/AndroidRuntime(598): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
04-23 20:17:43.895: E/AndroidRuntime(598): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
04-23 20:17:43.895: E/AndroidRuntime(598): at dalvik.system.NativeStart.main(Native Method)
04-23 20:17:43.895: E/AndroidRuntime(598): Caused by: java.lang.NullPointerException
04-23 20:17:43.895: E/AndroidRuntime(598): at com.example.rubrica.Persona.getData(Persona.java:72)
04-23 20:17:43.895: E/AndroidRuntime(598): at com.example.rubrica.SqlView.onCreate(SqlView.java:16)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.Activity.performCreate(Activity.java:4465)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
04-23 20:17:43.895: E/AndroidRuntime(598): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
04-23 20:17:43.895: E/AndroidRuntime(598): ... 11 more


e di seguito Persona.java:


package com.example.rubrica;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class Persona {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "persons_name";
public static final String KEY_SURNAME = "persons_surname";

private static final String DATABASE_NAME = "Personadb";
private static final String DATABASE_TABLE = "peopleTable";
private static final int DATABASE_VERSION = 1;

private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;

private static class DbHelper extends SQLiteOpenHelper{

public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}

@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_SURNAME + " TEXT NOT NULL);"
);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
public Persona (Context c){
ourContext = c;
}

public Persona open() throws SQLException{
ourHelper = new DbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
return this;
}
public void close(){
ourHelper.close();
}

public long createEntry(String name, String surname) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, name);
cv.put(KEY_SURNAME, surname);
return ourDatabase.insert(DATABASE_TABLE, null, cv);
}

public String getData() {
// TODO Auto-generated method stub
String[] columns = new String[] {KEY_ROWID, KEY_NAME, KEY_SURNAME};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";


int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iSurname = c.getColumnIndex(KEY_SURNAME);

for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
result = result + c.getString(iRow) + " " + c.getString(iName) + " " + c.getString(iSurname) + "\n";
}
return result;
}
}


Ho seguito un tutorial online, aiutatemi sono un nuovo sviluppatore, grazie