Android examples for java.lang.reflect:Array Reflection
Checks if the object is in the given array. The method returns false if a null array is passed in.
/*//ww w.j a va 2 s.c o m * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ import java.lang.reflect.Array; import java.util.Arrays; import java.util.BitSet; import java.util.Comparator; import java.util.HashMap; import java.util.Map; public class Main{ /** * The index value when an element is not found in a list or array: {@code -1}. * This value is returned by methods in this class and can also be used in comparisons with values returned by * various method from {@link java.util.List}. */ public static final int INDEX_NOT_FOUND = -1; /** * <p>Checks if the object is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param objectToFind the object to find * @return {@code true} if the array contains the object */ public static boolean contains(final Object[] array, final Object objectToFind) { return indexOf(array, objectToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object */ public static boolean contains(final long[] array, final long valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object */ public static boolean contains(final int[] array, final int valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object */ public static boolean contains(final short[] array, final short valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object * @since 2.1 */ public static boolean contains(final char[] array, final char valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object */ public static boolean contains(final byte[] array, final byte valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object */ public static boolean contains(final double[] array, final double valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if a value falling within the given tolerance is in the * given array. If the array contains a value within the inclusive range * defined by (value - tolerance) to (value + tolerance).</p> * * <p>The method returns {@code false} if a {@code null} array * is passed in.</p> * * @param array the array to search * @param valueToFind the value to find * @param tolerance the array contains the tolerance of the search * @return true if value falling within tolerance is in array */ public static boolean contains(final double[] array, final double valueToFind, final double tolerance) { return indexOf(array, valueToFind, 0, tolerance) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object */ public static boolean contains(final float[] array, final float valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Checks if the value is in the given array.</p> * * <p>The method returns {@code false} if a {@code null} array is passed in.</p> * * @param array the array to search through * @param valueToFind the value to find * @return {@code true} if the array contains the object */ public static boolean contains(final boolean[] array, final boolean valueToFind) { return indexOf(array, valueToFind) != INDEX_NOT_FOUND; } /** * <p>Finds the index of the given object in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param objectToFind the object to find, may be {@code null} * @return the index of the object within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final Object[] array, final Object objectToFind) { return indexOf(array, objectToFind, 0); } /** * <p>Finds the index of the given object in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param objectToFind the object to find, may be {@code null} * @param startIndex the index to start searching at * @return the index of the object within the array starting at the index, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final Object[] array, final Object objectToFind, int startIndex) { if (array == null) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } if (objectToFind == null) { for (int i = startIndex; i < array.length; i++) { if (array[i] == null) { return i; } } } else if (array.getClass().getComponentType() .isInstance(objectToFind)) { for (int i = startIndex; i < array.length; i++) { if (objectToFind.equals(array[i])) { return i; } } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final long[] array, final long valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final long[] array, final long valueToFind, int startIndex) { if (array == null) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final int[] array, final int valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final int[] array, final int valueToFind, int startIndex) { if (array == null) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final short[] array, final short valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final short[] array, final short valueToFind, int startIndex) { if (array == null) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input * @since 2.1 */ public static int indexOf(final char[] array, final char valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input * @since 2.1 */ public static int indexOf(final char[] array, final char valueToFind, int startIndex) { if (array == null) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final byte[] array, final byte valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final byte[] array, final byte valueToFind, int startIndex) { if (array == null) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final double[] array, final double valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value within a given tolerance in the array. * This method will return the index of the first value which falls between the region * defined by valueToFind - tolerance and valueToFind + tolerance.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param tolerance tolerance of the search * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final double[] array, final double valueToFind, final double tolerance) { return indexOf(array, valueToFind, 0, tolerance); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final double[] array, final double valueToFind, int startIndex) { if (ArrayUtils.isEmpty(array)) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array starting at the given index. * This method will return the index of the first value which falls between the region * defined by valueToFind - tolerance and valueToFind + tolerance.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @param tolerance tolerance of the search * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) { if (ArrayUtils.isEmpty(array)) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } final double min = valueToFind - tolerance; final double max = valueToFind + tolerance; for (int i = startIndex; i < array.length; i++) { if (array[i] >= min && array[i] <= max) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final float[] array, final float valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final float[] array, final float valueToFind, int startIndex) { if (ArrayUtils.isEmpty(array)) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Finds the index of the given value in the array.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input */ public static int indexOf(final boolean[] array, final boolean valueToFind) { return indexOf(array, valueToFind, 0); } /** * <p>Finds the index of the given value in the array starting at the given index.</p> * * <p>This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array.</p> * * <p>A negative startIndex is treated as zero. A startIndex larger than the array * length will return {@link #INDEX_NOT_FOUND} ({@code -1}).</p> * * @param array the array to search through for the object, may be {@code null} * @param valueToFind the value to find * @param startIndex the index to start searching at * @return the index of the value within the array, * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} * array input */ public static int indexOf(final boolean[] array, final boolean valueToFind, int startIndex) { if (ArrayUtils.isEmpty(array)) { return INDEX_NOT_FOUND; } if (startIndex < 0) { startIndex = 0; } for (int i = startIndex; i < array.length; i++) { if (valueToFind == array[i]) { return i; } } return INDEX_NOT_FOUND; } /** * <p>Checks if an array of Objects is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final Object[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive longs is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final long[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive ints is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final int[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive shorts is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final short[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive chars is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final char[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive bytes is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final byte[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive doubles is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final double[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive floats is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final float[] array) { return array == null || array.length == 0; } /** * <p>Checks if an array of primitive booleans is empty or {@code null}.</p> * * @param array the array to test * @return {@code true} if the array is empty or {@code null} * @since 2.1 */ public static boolean isEmpty(final boolean[] array) { return array == null || array.length == 0; } }