org.apache.bval.util.ObjectUtils Maven / Gradle / Ivy
/*
* 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.
*/
package org.apache.bval.util;
import java.lang.annotation.Annotation;
import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Objects;
import java.util.function.Predicate;
import java.util.stream.Stream;
public final class ObjectUtils {
public static final Class[] EMPTY_CLASS_ARRAY = new Class[0];
public static final String[] EMPTY_STRING_ARRAY = new String[0];
public static final Annotation[] EMPTY_ANNOTATION_ARRAY = new Annotation[0];
private ObjectUtils() {
}
/**
* Returns a default value if the object passed is {@code null}.
*
*
* ObjectUtils.defaultIfNull(null, null) = null
* ObjectUtils.defaultIfNull(null, "") = ""
* ObjectUtils.defaultIfNull(null, "zz") = "zz"
* ObjectUtils.defaultIfNull("abc", *) = "abc"
* ObjectUtils.defaultIfNull(Boolean.TRUE, *) = Boolean.TRUE
*
*
* @param the type of the object
* @param object the {@code Object} to test, may be {@code null}
* @param defaultValue the default value to return, may be {@code null}
* @return {@code object} if it is not {@code null}, defaultValue otherwise
*/
public static T defaultIfNull(final T object, final T defaultValue) {
return object == null ? defaultValue : object;
}
public static boolean isEmptyArray(final Object array) {
return array == null || array.getClass().isArray() && Array.getLength(array) == 0;
}
/**
* Checks if the object is in the given array.
*
*
The method returns {@code false} if a {@code null} array is passed in.
*
* @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 arrayContains(final Object[] array, final Object objectToFind) {
if (array == null) {
return false;
}
return Stream.of(array).anyMatch(Predicate.isEqual(objectToFind));
}
public static int indexOf(final Object[] array, final Object objectToFind) {
for (int i = 0; i < array.length; i++) {
if (Objects.equals(array[i], objectToFind)) {
return i;
}
}
return -1;
}
public static T[] arrayAdd(T[] array, T objectToAdd) {
if (array == null && objectToAdd == null) {
throw new IllegalArgumentException("Arguments cannot both be null");
}
final int arrayLength = Array.getLength(array);
@SuppressWarnings("unchecked")
T[] newArray = (T[]) Array.newInstance(array.getClass().getComponentType(), arrayLength + 1);
System.arraycopy(array, 0, newArray, 0, arrayLength);
newArray[newArray.length - 1] = objectToAdd;
return newArray;
}
/**
* Get hashcode of {@code o}, taking into account array values.
* @param o
* @return {@code int}
* @see Arrays
* @see Objects#hashCode(Object)
*/
public static int hashCode(Object o) {
if (o instanceof Object[]) {
return Arrays.hashCode((Object[]) o);
}
if (o instanceof byte[]) {
return Arrays.hashCode((byte[]) o);
}
if (o instanceof short[]) {
return Arrays.hashCode((short[]) o);
}
if (o instanceof int[]) {
return Arrays.hashCode((int[]) o);
}
if (o instanceof char[]) {
return Arrays.hashCode((char[]) o);
}
if (o instanceof long[]) {
return Arrays.hashCode((long[]) o);
}
if (o instanceof float[]) {
return Arrays.hashCode((float[]) o);
}
if (o instanceof double[]) {
return Arrays.hashCode((double[]) o);
}
if (o instanceof boolean[]) {
return Arrays.hashCode((boolean[]) o);
}
return Objects.hashCode(o);
}
}