Question

=== about me ===

I’m new to android development and barely able to “speak” Java. Nevertheless I’m experienced in PHP5 and C++ C++/CLI (.net >2.0) so I hope I’ll be able to create this little app, that is in my mind.

But after a few days of experimenting I’m in a kind of pitfall now, and hope you can help me.

=== about the project ===

I’ve got an listview (nested within other layout) and try to populate it with data from a sqlite. I managed to get the thing up and running with a simple “arrayAdapter”, but researching how I could update it if I insert new elemnts in the database with a popup I figured out that I need to implement my own content provider.

=== about the problem ===

I browsed a few tutorials and did so, but now I have problems calling it because of the URI. I don’t understand how it should be created and so I can’t create a valid one.

Here is the problem in code:

TBTTManageBudgetsActivity.java

package com.TBTT;

// ...
// some imports
// ...

public class TBTTManageBudgetsActivity extends Activity {
    // ...
    // some declarations
    // ...

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

        // ...
        // some stuff concerning other elements
        // ...

    // Fill List View
        // Get the list view
            ListView listView = (ListView) findViewById(R.id.list_box);     
            // Get content provider and cursor
                String[] projection = { TBTCPHBudget.KEY_ROWID, TBTCPHBudget.KEY_NAME };
                String[] uiBindFrom = { TBTCPHBudget.KEY_ROWID};
                int[] uiBindTo = { R.id.name };             
                TBTCPBdugets ContentProvider = new TBTCPBdugets();        
                Cursor cursor = ContentProvider.query(TBTCPBdugets.CONTENT_URI, projection,null, null, null);               
            // Let activity manage the cursor
                startManagingCursor(cursor);
            // Get value from content provider
                cursor.moveToFirst();
                ArrayList list = new ArrayList<String>();
                do {
                    list.add(cursor.getString(1));
                } while (cursor.moveToNext());
            // Set Values with Adapter
                CursorAdapter adapter = new SimpleCursorAdapter(this.getApplicationContext(), R.layout.list_budgets_item, cursor, uiBindFrom, uiBindTo);
                listView.setAdapter(adapter);               
    }

    // ...
    // some other functions
    // ...
}

TBTCPBdugets.java

package com.TBTT;
// ...
// some imports
// ...

public class TBTCPBdugets extends ContentProvider {
    // ...
    // some declarations
    // ...
    public static final String AUTHORITY = "com.TBTT";
    public static final String DATAPATH = "TBTCPHBudget";
    public static final Uri CONTENT_URI = Uri.parse("content://"+ AUTHORITY+"/" + DATAPATH);
    private static final UriMatcher sUriMatcher;

    private static class DatabaseHelper extends SQLiteOpenHelper {
        // ...
        // some other functions
        // ...
    }

    private DatabaseHelper dbHelper;

    // ...
    // some other functions
    // ...

    @Override
    public boolean onCreate() {
        dbHelper = new DatabaseHelper(getContext());
        return true;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
        switch (sUriMatcher.match(uri)) {        
            case BUDGETS:               
                qb.setTables(BUDGETS_TABLE_NAME);            
                qb.setProjectionMap(notesProjectionMap);
                break;
        default:            
            Log.d(TAG, "Unknown URI " + uri+" with URIMatcher Result "+sUriMatcher.match(uri));             
            throw new IllegalArgumentException("Unknown URI " + uri);
        }

        SQLiteDatabase db = dbHelper.getReadableDatabase();
        Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, sortOrder);

        c.setNotificationUri(getContext().getContentResolver(), uri);
        return c;
    }

    static {
        sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
        sUriMatcher.addURI(AUTHORITY, BUDGETS_TABLE_NAME, BUDGETS);

        // ...
        // some declarations
        // ...
    }
}

When I run this and open the TBTTManageBudgetsActivity the program will crash. The debug output from the TBTCPBdugets.java says: “Unknown URI content://com.TBTT/TBTCPBdugets with URIMatcher Result -1”.

Can anybody tell me please how to create a VALID URI for this?

Answer 1

Your UriMatcher don’t know about your CONTENT_URI. There are DATAPATH in CONTENT_URI, but BUDGETS_TABLE_NAME in matcher.