android galaxy s real device database file to null point exception

Question

I am loading a database file in assets called mydb. I then use the code below to load the database file onto the emulator. This works sometimes but not always. I reset eclipse and the database file loads up correctly. I cannot get it to work at all on the real device. I have tried this with other experiemental files project. I think there is a setting I have not configured correctly but I am not not sure. Any help would be greatly appreciated.

methods tried

1. I tried to use the android_meta table as this was suggest to fix issues of databases not being loaded.

2. I can also had records using this sort of syntax. This will even work on the lives device long id = db.insertContact("Wei-Meng Lee", "[email protected]"); This code snipet is taken from the book android development

3. I am making the code alterations that where specified in the example

entire fault log

06-21 15:17:56.792: E/AndroidRuntime(556): FATAL EXCEPTION: main 06-21 15:17:56.792: E/AndroidRuntime(556): java.lang.RuntimeException: Unable to start activity ComponentInfo{alex.android.test.db/alex.android.test.db.AndroidtestdbActivity}: android.database.sqlite.SQLiteException: no such table: contacts: , while compiling: SELECT DISTINCT _id, name, email FROM contacts WHERE _id=2 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.ActivityThread.access$600(ActivityThread.java:123) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.os.Handler.dispatchMessage(Handler.java:99) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.os.Looper.loop(Looper.java:137) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.ActivityThread.main(ActivityThread.java:4424) 06-21 15:17:56.792: E/AndroidRuntime(556): at java.lang.reflect.Method.invokeNative(Native Method) 06-21 15:17:56.792: E/AndroidRuntime(556): at java.lang.reflect.Method.invoke(Method.java:511) 06-21 15:17:56.792: E/AndroidRuntime(556): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 06-21 15:17:56.792: E/AndroidRuntime(556): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 06-21 15:17:56.792: E/AndroidRuntime(556): at dalvik.system.NativeStart.main(Native Method) 06-21 15:17:56.792: E/AndroidRuntime(556): Caused by: android.database.sqlite.SQLiteException: no such table: contacts: , while compiling: SELECT DISTINCT _id, name, email FROM contacts WHERE _id=2 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteCompiledSql.(SQLiteCompiledSql.java:68) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteProgram.compileSql(SQLiteProgram.java:143) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteProgram.compileAndbindAllArgs(SQLiteProgram.java:361) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteProgram.(SQLiteProgram.java:127) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteProgram.(SQLiteProgram.java:94) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteQuery.(SQLiteQuery.java:53) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:47) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1564) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1449) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1405) 06-21 15:17:56.792: E/AndroidRuntime(556): at alex.android.test.db.DBAdapter.getContact(DBAdapter.java:163) 06-21 15:17:56.792: E/AndroidRuntime(556): at alex.android.test.db.AndroidtestdbActivity.onCreate(AndroidtestdbActivity.java:32) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.Activity.performCreate(Activity.java:4465) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 06-21 15:17:56.792: E/AndroidRuntime(556): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)

public class DBAdapter {

 private static final String DB_NAME = "MyDB";
private static final int DB_VERSION = 1;
 public static final String KEY_ROWID = "_id";
    public static final String KEY_NAME = "name";
    public static final String KEY_EMAIL = "email";
    private static final String TAG = "DBAdapter";
    private static final String DATABASE_TABLE = "contacts";

private static Context c;
private SQLiteDatabase db;
private SQLiteOpenHelper sqlDBHelp;

/**
 * Constructor for the SQL DB Adapter, copy DB from assets if not exists in /data/data/<package-name>/databases
 * 
 * @param c
 */
public DBAdapter(Context c) {
    super();
    DBAdapter.c = c;
    sqlDBHelp = new SqlDBHelper();
}

/**
 * Open the SQL DB as Writable
 */
public void openDB() {
    try {
        db = sqlDBHelp.getWritableDatabase();
    } catch (SQLiteException ex) {
        Toast.makeText(c, "DB with filename " + DB_NAME + "coudn't be opend!", Toast.LENGTH_SHORT);
    }
}

/**
 * Close the SQL DB
 */
public void closeDB() {
    db.close();
}

/**
 * Helper class for the SQL DB Adapter
 */
static class SqlDBHelper extends SQLiteOpenHelper {

    private static final String DB_PATH = "/data/data/" + c.getPackageName() + "/databases/" + DB_NAME;

    public SqlDBHelper() {
        super(c, DB_NAME, null, DB_VERSION);
        createDB();     
    }

    private void createDB() {

        SharedPreferences prefs = c.getSharedPreferences("sharedPrefs", 0);
        boolean dbExists = prefs.getBoolean("dbExists", false);
        Log.d("PM.ADA.SDA", "DB Exists : " + dbExists);
        if (!dbExists) {
            this.getReadableDatabase();
            copyDB();
            prefs.edit().putBoolean("dbExists", true).commit();
        }
    }


    public void onCreate(SQLiteDatabase db) {
        /*
        try {
            db.execSQL(DATABASE_TABLE); 
        } catch (SQLException e) {
            e.printStackTrace();
        }   
        */

    }

    @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 contacts");
            onCreate(db);


    }

    public void copyDB() {
        try {               
            InputStream is = c.getAssets().open(DB_NAME);
            BufferedInputStream bis = new BufferedInputStream(is);
            OutputStream os = new FileOutputStream(DB_PATH);
            BufferedOutputStream bos = new BufferedOutputStream(os);

            byte[] buffer = new byte[64];
            int length;

            while ((length = bis.read(buffer)) > 0) {
                bos.write(buffer, 0, length);
            }

            bos.flush();
            bos.close();
            bis.close();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

public long insertContact(String name, String email) 
{
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_NAME, name);
    initialValues.put(KEY_EMAIL, email);
    return db.insert(DATABASE_TABLE, null, initialValues);
}

//---deletes a particular contact---
public boolean deleteContact(long rowId) 
{
    return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}

//---retrieves all the contacts---
public Cursor getAllContacts() 
{
    return db.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_NAME,
            KEY_EMAIL}, null, null, null, null, null);
}

//---retrieves a particular contact---
public Cursor getContact(long rowId) throws SQLException 
{
    Cursor mCursor =
            db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
            KEY_NAME, KEY_EMAIL}, KEY_ROWID + "=" + rowId, null,
            null, null, null, null);
    if (mCursor != null) {
        mCursor.moveToFirst();
    }
    return mCursor;
}

//---updates a contact---
public boolean updateContact(long rowId, String name, String email) 
{
    ContentValues args = new ContentValues();
    args.put(KEY_NAME, name);
    args.put(KEY_EMAIL, email);
    return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}

}

other activity TextView name;

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

    DBAdapter db = new DBAdapter(this); 
    name = (TextView)findViewById(R.id.name);



    //---get a contact---
    db.openDB();
    Cursor c = db.getContact(2);
    if (c.moveToFirst())  
    {
        DisplayContact(c);
    name.setText(String.valueOf(c.getString(1)));
    }
    else
        name.setText("not found");
        Toast.makeText(this, "No contact found", Toast.LENGTH_LONG).show();
    db.closeDB();

}

public void DisplayContact(Cursor c)
{
    Toast.makeText(this, 
            "id: " + c.getString(0) + "\n" +
            "Name: " + c.getString(1) + "\n" +
            "Email:  " + c.getString(2),
            Toast.LENGTH_LONG).show();  


}  

}

Answer 1

I see a few differences from how I do it... You are missing an outputStream.flush(), and I call this.getReadableDatabase(); before I start my copy process and this.close(); after.

For your reference, here is how I do it and it works fine:

private static class DatabaseHelper extends SQLiteOpenHelper {
    DatabaseHelper(Context context, String dbname, int dbversion) {
        super(context, dbname, null, dbversion);
        if (checkDataBase(dbname)) {
            openDataBase(dbname);
        } else {
            try {
                this.getReadableDatabase();
                copyDataBase(dbname);
                this.close();
                openDataBase(dbname);
            } catch (IOException e) {
                throw new Error("Error copying database");
            }
            Toast.makeText(context,
                    "Initial " + dbname + " database has been created",
                    Toast.LENGTH_LONG).show();
        }
    }


public DBAdapter(Context ctx) {
    DBAdapter.mCtx = ctx;
}

private static boolean checkDataBase(String dbname) {
    SQLiteDatabase checkDB = null;
    boolean exist = false;
    try {
        String db = MAIN_DB_PATH + dbname;
        checkDB = SQLiteDatabase.openDatabase(db, null,
                SQLiteDatabase.OPEN_READONLY);
    } catch (SQLiteException e) {
        Log.v("db log", "database does't exist");
    }
    if (checkDB != null) {
        exist = true;
        checkDB.close();
    }
    return exist;
}

private static void copyDataBase(String dbname) throws IOException {
    InputStream myInput = mCtx.getAssets().open(dbname);
    String outFileName = MAIN_DB_PATH + dbname;
    OutputStream myOutput = new FileOutputStream(outFileName);
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer)) > 0) {
        myOutput.write(buffer, 0, length);
    }
    myOutput.flush();
    myOutput.close();
    myInput.close();
}