DataContentProvider.java

package com.example.nikhil.simpledatabase.database;

import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;


public class DataContentProvider extends ContentProvider{

    private static final String TAG = "DataContentProvider";

    public static final int ITEM_CODE = 1001;
    public static final int ITEM_ID_CODE = 1002;

    public static final UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);
    private DataHelper mDbHelper;

    static {
        matcher.addURI(DataContract.DataProvider.AUTHORITY, DataContract.DataProvider.PATH_TABLE,ITEM_CODE);
        matcher.addURI(DataContract.DataProvider.AUTHORITY, DataContract.DataProvider.PATH_ID_TABLE, ITEM_ID_CODE);
    }

    @Override
    public boolean onCreate() {
        mDbHelper = new DataHelper(getContext());
        return true;
    }

    @Nullable
    @Override
    public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String s1) {
        SQLiteDatabase database = mDbHelper.getReadableDatabase();
        int code = matcher.match(uri);
        Cursor cursor = null;
        switch (code) {
            case ITEM_CODE :
                cursor = database.query(DataContract.DataProvider.TABLE_NAME,
                        projection,
                        selection,
                        selectionArgs,
                        null,
                        null,
                        null);
                break;
            case ITEM_ID_CODE :
                selection = DataContract.DataProvider.COLUMN_ID + "=?";
                selectionArgs = new String[]{String.valueOf(ContentUris.parseId(uri))};
                cursor = database.query(DataContract.DataProvider.TABLE_NAME,
                        projection,
                        selection,
                        selectionArgs,
                        null,null,null);
                break;
            default:
                throw new IllegalArgumentException("Failed to query data for uri : " + uri);
        }
        cursor.setNotificationUri(getContext().getContentResolver(),uri);
        return cursor;
    }

    @Nullable
    @Override
    public String getType(@NonNull Uri uri) {
        int code = matcher.match(uri);
        if(code == ITEM_CODE)
            return DataContract.DataProvider.CONTENT_LIST_TYPE;
        else
            return DataContract.DataProvider.CONTENT_ITEM_TYPE;
    }

    @Nullable
    @Override
    public Uri insert(@NonNull Uri uri, @Nullable ContentValues contentValues) {
        SQLiteDatabase database = mDbHelper.getWritableDatabase();
        String item_name = contentValues.getAsString(DataContract.DataProvider.COLUMN_DATA_ITEM);
        if(item_name.isEmpty())
            throw new IllegalArgumentException("Incomplete Data! Insert failed.");
        long id;
        id = database.insert(DataContract.DataProvider.TABLE_NAME, null, contentValues);
        if(id != -1)
        {
            Uri uriReturn = ContentUris.withAppendedId(uri,id);
            getContext().getContentResolver().notifyChange(uri,null);
            return uriReturn;
        }
        else
            throw new IllegalArgumentException("Insert failed!");
    }

    @Override
    public int delete(@NonNull Uri uri, @Nullable String selection, @Nullable String[] selectionArgs) {
        SQLiteDatabase database = mDbHelper.getWritableDatabase();
        int code = matcher.match(uri);
        int row;
        switch (code){
            case ITEM_CODE :
                row = database.delete(DataContract.DataProvider.TABLE_NAME,null,null);
                getContext().getContentResolver().notifyChange(uri,null);
                return row;
            case ITEM_ID_CODE :
                selection = DataContract.DataProvider.COLUMN_ID + "=?";
                selectionArgs = new String[]{String.valueOf(ContentUris.parseId(uri))};
                row = database.delete(DataContract.DataProvider.TABLE_NAME,selection,selectionArgs);
                getContext().getContentResolver().notifyChange(uri,null);
                return row;
        }
        return 0;
    }

    @Override
    public int update(@NonNull Uri uri, @Nullable ContentValues contentValues, @Nullable String selection, @Nullable String[] selectionArgs) {
        SQLiteDatabase database = mDbHelper.getWritableDatabase();
        int id;
        selection = DataContract.DataProvider.COLUMN_ID + "=?";
        selectionArgs = new String[]{String.valueOf(ContentUris.parseId(uri))};
        id = database.update(DataContract.DataProvider.TABLE_NAME,contentValues,selection,selectionArgs);
        getContext().getContentResolver().notifyChange(uri,null);
        return id;
    }
}