Error populating ListView from Database

Error populating ListView from Database

So, meet a brick wall. Finally confirmed that my database is coping to the
data/data folder (it is a static database I have created), and it seems
like the app is able to find it, but when trying to pull data from the
database to inflate the ListView, I am running into an error that I can't
resolve. (at least that is what I assume is happening)
08-15 00:11:36.771: E/AndroidRuntime(7000): FATAL EXCEPTION: main
08-15 00:11:36.771: E/AndroidRuntime(7000): java.lang.RuntimeException:
Unable to start activity
ComponentInfo{table.periodic/table.periodic.elementList}:
java.lang.NullPointerException
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.ActivityThread.access$600(ActivityThread.java:141)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.os.Handler.dispatchMessage(Handler.java:99)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.os.Looper.loop(Looper.java:137)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.ActivityThread.main(ActivityThread.java:5041)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
java.lang.reflect.Method.invokeNative(Native Method)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
java.lang.reflect.Method.invoke(Method.java:511)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
dalvik.system.NativeStart.main(Native Method)
08-15 00:11:36.771: E/AndroidRuntime(7000): Caused by:
java.lang.NullPointerException
08-15 00:11:36.771: E/AndroidRuntime(7000): at
table.periodic.elementList.populateListViewFromDatabase(elementList.java:24)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
table.periodic.elementList.onCreate(elementList.java:19)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.Activity.performCreate(Activity.java:5104)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
08-15 00:11:36.771: E/AndroidRuntime(7000): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
08-15 00:11:36.771: E/AndroidRuntime(7000): ... 11 more
So, I can see where it is saying that my error is, however, when I look at
the code, nothing seems to be wrong.
My DataBaseHelper.class
public class DataBaseHelper extends SQLiteOpenHelper{
private SQLiteDatabase myDataBase;
public static final int DATABASE_VERSION = 1;
private final Context myContext;
private static String DB_PATH = "data/data/table.periodic/databases/";
private static String DB_NAME = "elements";
public static final String DB_TABLE = "elements";
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "name";
public static final String KEY_ATOMIC_NUMBER = "atomic number";
public static final String KEY_ATOMIC_WEIGHT = "atomic weight";
public static final String KEY_OXIDATION = "oxidation";
public static final String KEY_SYMBOL = "symbol";
public static final String KEY_BOILING_POINT = "boiling point";
public static final String KEY_MELTING_POINT = "melting point";
public static final String KEY_DENSITY = "density";
public static final String KEY_ELECTRON_CONFIGURATION = "electron
configuration";
public static final String KEY_STRUCTURE = "structure";
public static final String KEY_COVALENT_RADIUS = "covalent radius";
public static final String KEY_ATOMIC_RADIUS = "atomic radius";
public static final String KEY_VOLUME = "volume";
public static final String KEY_ION_POTENTIAL = "ion potential";
public static final String KEY_HEAT_CAPACITY = "heat capacity";
public static final String KEY_ELECTRONEGATIVITY = "electronegativity";
public static final String KEY_VAPORATION = "vaporation";
public static final String KEY_FUSION = "fusion";
public static final String KEY_ELECTRO_CONDUCTIVITY = "electro
conductivity";
public static final String KEY_THERMAL_CONDUCTIVITY = "thermal
conductivity";
public static final int COL_ROWID = 0;
public static final int COL_NAME = 1;
public static final int COL_ATOMIC_NUMBER = 2;
public static final int COL_ATOMIC_WEIGHT = 3;
public static final int COL_OXIDATION = 4;
public static final int COL_SYMBOL = 5;
public static final int COL_BOILING_POINT = 6;
public static final int COL_MELTING_POINT = 7;
public static final int COL_DENSITY = 8;
public static final int COL_ELECTRON_CONFIGURATION = 9;
public static final int COL_STRUCTURE = 10;
public static final int COL_COVALENT_RADIUS = 11;
public static final int COL_ATOMIC_RADIUS = 12;
public static final int COL_VOLUME = 13;
public static final int COL_ION_POTENTIAL = 14;
public static final int COL_HEAT_CAPACITY = 15;
public static final int COL_ELECTRONEGATIVITY = 16;
public static final int COL_VAPORATION = 17;
public static final int COL_FUSION = 18;
public static final int COL_ELECTRO_CONDUCTIVITY = 19;
public static final int COL_THERMAL_CONDUCTIVITY = 20;
public static final String[] ALL_KEYS = new String[] {KEY_ROWID,
KEY_NAME, KEY_ATOMIC_NUMBER, KEY_ATOMIC_WEIGHT,
KEY_OXIDATION, KEY_SYMBOL, KEY_BOILING_POINT, KEY_MELTING_POINT,
KEY_DENSITY, KEY_ELECTRON_CONFIGURATION,
KEY_STRUCTURE, KEY_COVALENT_RADIUS, KEY_ATOMIC_RADIUS, KEY_VOLUME,
KEY_ION_POTENTIAL, KEY_HEAT_CAPACITY,
KEY_ELECTRONEGATIVITY, KEY_VAPORATION, KEY_FUSION,
KEY_ELECTRO_CONDUCTIVITY, KEY_THERMAL_CONDUCTIVITY};
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
public void createDataBase() throws IOException {
boolean dbExists = checkDataBase();
if (dbExists) {
} else {
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
}
if (checkDB !=null){
checkDB.close();
}
return checkDB !=null ? true : false;
}
private void copyDataBase() throws IOException{
InputStream myInput = myContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
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();
}
public void openDataBase() throws SQLException{
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
public Cursor getAllRows() {
String where = null;
Cursor c = myDataBase.query(true, DB_TABLE, ALL_KEYS,
where, null, null, null, null, null, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
public Cursor getRow(long rowId) {
String where = KEY_ROWID + "=" + rowId;
Cursor c = myDataBase.query(true, DB_TABLE, ALL_KEYS,
where, null, null, null, null, null, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
@Override
public synchronized void close() {
if(myDataBase !=null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int
newVersion){
}
}
My elementList.class
public class elementList extends Activity {
private String[] sElements;
DataBaseHelper myDB;
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.list_view);
**line 19-->** populateListViewFromDatabase();
}
private void populateListViewFromDatabase() {
**line 24-->** Cursor cursor = myDB.getAllRows();
startManagingCursor(cursor);
String[] fromFieldNames = new String[]
{DataBaseHelper.KEY_NAME};
int[] toViewIDs = new int[]
{R.id.elListText};
SimpleCursorAdapter myCursorAdapter =
new SimpleCursorAdapter(
this,
R.layout.el_list_item,
cursor,
fromFieldNames,
toViewIDs
);
ListView myList = (ListView) findViewById(R.id.list);
myList.setAdapter(myCursorAdapter);
}
private void openDB() {
myDB = new DataBaseHelper(this);
myDB.openDataBase();
}
@Override
public void onDestroy() {
super.onDestroy();
closeDB();
}
private void closeDB() {
myDB.close();
}
}
I previously was also receiving an error with relation to the getAllRows
in my DataBaseHelper class, but that seems to be resolved now.