Java tutorial
/* * Copyright (C) 2011 The Android Open Source Project * * 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 android.support.v4.database; import android.text.TextUtils; /** * Helper for accessing features in {@link android.database.DatabaseUtils} * introduced after API level 4 in a backwards compatible fashion. */ public class DatabaseUtilsCompat { private DatabaseUtilsCompat() { /* Hide constructor */ } /** * Concatenates two SQL WHERE clauses, handling empty or null values. */ public static String concatenateWhere(String a, String b) { if (TextUtils.isEmpty(a)) { return b; } if (TextUtils.isEmpty(b)) { return a; } return "(" + a + ") AND (" + b + ")"; } /** * Appends one set of selection args to another. This is useful when adding a selection * argument to a user provided set. */ public static String[] appendSelectionArgs(String[] originalValues, String[] newValues) { if (originalValues == null || originalValues.length == 0) { return newValues; } String[] result = new String[originalValues.length + newValues.length]; System.arraycopy(originalValues, 0, result, 0, originalValues.length); System.arraycopy(newValues, 0, result, originalValues.length, newValues.length); return result; } }