i second saurav.. do this:
public class myact extends Activity {
public static final String KEY_ROWID = "_id";
public static final String KEY_VEHICLE = "vehicle";
public static final String KEY_ROUTE = "route";
public static final String KEY_COUNTRY = "country";
public static final String KEY_CITY = "city";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "publicTransport";
private static final String DATABASE_TABLE = "vehicleTable";
private static final int DATABASE_VERSION = 1;
long id;
Cursor c;
private static final String DATABASE_CREATE = "create table vehicleTable
(_id integer primary key autoincrement, "
+ "vehicle text not null, route text not null, "
+ "country text not null,city text not null);";
private final Context context = this;
private DatabaseHelper DBHelper;
private SQLiteDatabase sqlitedatabase;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
DBHelper = new DatabaseHelper(context);
try {
sqlitedatabase = DBHelper.getWritableDatabase();
} catch (Exception e) {
Toast.makeText(this, "misfunctioning open" + e.toString(),
Toast.LENGTH_LONG).show();
}
}
class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int
newVersion) {
db.execSQL("DROP TABLE IF EXISTS titles");
onCreate(db);
}
}
}
On Wed, Aug 5, 2009 at 5:34 PM, Saurav Mukherjee <
[email protected]> wrote:
> i dont know how far i am right, but doesn't the context change when u
> instantiate a new activity object?
> >myact maobj=new myact();
> hence the exception.
> jus move the code in open() to the line after dbhelper instatiation. it
> should work fine. there is no need to create a new activity object.
>
>
> On Wed, Aug 5, 2009 at 5:02 PM, saptarshi chatterjee <
> [email protected]> wrote:
>
>>
>> Friends,
>>
>> In the following code the method "public void open() throws
>> SQLException " is throwing NullPointeeException. Please help me.
>>
>> Thanks & Regards
>> Saptarshi
>>
>>
>>
>> package com.outp.inp;
>>
>>
>> import android.app.Activity;
>> import android.content.Context;
>> import android.database.Cursor;
>> import android.database.SQLException;
>> import android.database.sqlite.SQLiteDatabase;
>> import android.database.sqlite.SQLiteOpenHelper;
>> import android.os.Bundle;
>> import android.util.Log;
>> import android.widget.Toast;
>>
>>
>> public class myact extends Activity {
>>
>>
>> public static final String KEY_ROWID = "_id";
>> public static final String KEY_VEHICLE = "vehicle";
>> public static final String KEY_ROUTE = "route";
>> public static final String KEY_COUNTRY = "country";
>> public static final String KEY_CITY = "city";
>> private static final String TAG = "DBAdapter";
>>
>> private static final String DATABASE_NAME = "publicTransport";
>> private static final String DATABASE_TABLE = "vehicleTable";
>> private static final int DATABASE_VERSION = 1;
>>
>> long id;
>> Cursor c;
>>
>> private static final String DATABASE_CREATE =
>> "create table vehicleTable (_id integer primary key
>> autoincrement, "
>> + "vehicle text not null, route text not null, "
>> + "country text not null,city text not null);";
>>
>>
>> private final Context context=this;
>> private DatabaseHelper DBHelper;
>> private SQLiteDatabase sqlitedatabase;
>>
>>
>>
>>
>>
>>
>>
>>
>> /** Called when the activity is first created. */
>> @Override
>> public void onCreate(Bundle savedInstanceState) {
>> super.onCreate(savedInstanceState);
>> setContentView(R.layout.main);
>>
>> DBHelper = new DatabaseHelper(context);
>> myact maobj=new myact();
>> try{
>> maobj.open();}
>> catch(Exception e){Toast.makeText(this, "misfunctioning
>> open"+e.toString(),Toast.LENGTH_LONG).show();}
>>
>>
>> }
>>
>>
>>
>> private static class DatabaseHelper extends SQLiteOpenHelper
>> {
>> DatabaseHelper(Context context)
>> {
>> super(context, DATABASE_NAME, null, DATABASE_VERSION);
>>
>> }
>>
>>
>> public void onCreate(SQLiteDatabase db)
>> {
>>
>> db.execSQL(DATABASE_CREATE);
>>
>>
>> }
>>
>> @Override
>> public void onUpgrade(SQLiteDatabase db, int oldVersion,
>> int newVersion)
>> {
>> Log.w(TAG, "Upgrading database from version " +
>> oldVersion
>> + " to "
>> + newVersion + ", which will destroy all old data");
>> db.execSQL("DROP TABLE IF EXISTS titles");
>> onCreate(db);
>> }
>> }
>>
>>
>>
>>
>> public void open() throws SQLException
>> {
>>
>> sqlitedatabase = DBHelper.getWritableDatabase();
>> }
>>
>>
>> }
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
> >
>
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