Android Open Source - android-memento Content Provider Util

From Project

License

The source code is released under:

Apache License

If you think the Android project android-memento listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.

Java Source Code

/*
 * android-memento-lib https://github.com/twofortyfouram/android-memento
 * Copyright 2014 two forty four a.m. LLC
 *//from   w w w .  j a va  2 s .c o m
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.twofortyfouram.memento.provider;

import com.twofortyfouram.annotation.Slow;
import com.twofortyfouram.annotation.Slow.Speed;
import com.twofortyfouram.assertion.Assertions;
import com.twofortyfouram.log.Lumberjack;

import net.jcip.annotations.ThreadSafe;

import android.content.ContentProvider;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.provider.BaseColumns;
import android.support.annotation.NonNull;

/**
 * Utility class for working with {@link ContentProvider}.
 */
@ThreadSafe
public final class ContentProviderUtil {

    /**
     * Projection for {@link BaseColumns#_COUNT}.
     */
    @NonNull
    private static final String[] PROJECTION_COUNT = {
            BaseColumns._COUNT
    };

    /**
     * @param context Application context.
     * @param uri     URI to count.
     * @return The number of rows for {@code uri}.
     */
    @Slow(Speed.MILLISECONDS)
    public static int getCountForUri(@NonNull final Context context, @NonNull final Uri uri) {
        Assertions.assertNotNull(context, "context"); //$NON-NLS-1$
        Assertions.assertNotNull(uri, "uri"); //$NON-NLS-1$

        int result = 0;

        Cursor cursor = null;
        try {
            cursor = context.getContentResolver().query(uri, PROJECTION_COUNT, null, null, null);

            if (null != cursor) {
                final int cursorCount = cursor.getCount();
                if (1 != cursorCount) {
                    final String message = Lumberjack.formatMessage(
                            "Row count should be 1 but was actually %d", cursorCount); //$NON-NLS-1$
                    throw new AssertionError(message);
                }
                cursor.moveToPosition(0);
                result = cursor.getInt(cursor.getColumnIndexOrThrow(BaseColumns._COUNT));
            }

        } finally {
            if (null != cursor) {
                cursor.close();
                cursor = null;
            }
        }

        return result;
    }

    /**
     * Private constructor prevents instantiation.
     *
     * @throws UnsupportedOperationException because this class cannot be instantiated.
     */
    private ContentProviderUtil() {
        throw new UnsupportedOperationException("This class is non-instantiable"); //$NON-NLS-1$
    }
}

Java Source Code List