/*
* Copyright (C) 2012 Stormpath, Inc.
*
* 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 org.jersey2.simple.lang;
import java.util.Arrays;
/**
* Various object utility methods.
*/
public class ObjectUtils {
public static final int INITIAL_HASH = 7;
public static final int MULTIPLIER = 31;
/**
* Return the same value as <code>{@link Boolean#hashCode()}</code>.
*
* @param b the boolean to hash.
* @return the same value as <code>{@link Boolean#hashCode()}</code>.
* @see Boolean#hashCode()
*/
public static int hashCode(boolean b) {
return b ? 1231 : 1237;
}
/**
* Return the same value as <code>{@link Double#hashCode()}</code>.
*
* @param dbl the double to hash
* @return the same value as <code>{@link Double#hashCode()}</code>
* @see Double#hashCode()
*/
public static int hashCode(double dbl) {
long bits = Double.doubleToLongBits(dbl);
return hashCode(bits);
}
/**
* Return the same value as <code>{@link Float#hashCode()}</code>.
*
* @param flt the float to hash
* @return the save value as <code>{@link Float#hashCode()}</code>.
* @see Float#hashCode()
*/
public static int hashCode(float flt) {
return Float.floatToIntBits(flt);
}
/**
* Return the same value as <code>{@link Long#hashCode()}</code>.
*
* @param l the long to hash
* @return the same value as <code>{@link Long#hashCode()}</code>.
* @see Long#hashCode()
*/
public static int hashCode(long l) {
return (int) (l ^ (l >>> 32));
}
/**
* Determine if the given objects are equal, returning <code>true</code>
* if both are <code>null</code> or <code>false</code> if only one is
* <code>null</code>.
* <p>Compares arrays with <code>Arrays.equals</code>, performing an equality
* check based on the array elements rather than the array reference.
*
* @param o1 first Object to compare
* @param o2 second Object to compare
* @return whether the given objects are equal
* @see java.util.Arrays#equals
*/
public static boolean nullSafeEquals(Object o1, Object o2) {
if (o1 == o2) {
return true;
}
if (o1 == null || o2 == null) {
return false;
}
if (o1.equals(o2)) {
return true;
}
if (o1.getClass().isArray() && o2.getClass().isArray()) {
if (o1 instanceof Object[] && o2 instanceof Object[]) {
return Arrays.equals((Object[]) o1, (Object[]) o2);
}
if (o1 instanceof boolean[] && o2 instanceof boolean[]) {
return Arrays.equals((boolean[]) o1, (boolean[]) o2);
}
if (o1 instanceof byte[] && o2 instanceof byte[]) {
return Arrays.equals((byte[]) o1, (byte[]) o2);
}
if (o1 instanceof char[] && o2 instanceof char[]) {
return Arrays.equals((char[]) o1, (char[]) o2);
}
if (o1 instanceof double[] && o2 instanceof double[]) {
return Arrays.equals((double[]) o1, (double[]) o2);
}
if (o1 instanceof float[] && o2 instanceof float[]) {
return Arrays.equals((float[]) o1, (float[]) o2);
}
if (o1 instanceof int[] && o2 instanceof int[]) {
return Arrays.equals((int[]) o1, (int[]) o2);
}
if (o1 instanceof long[] && o2 instanceof long[]) {
return Arrays.equals((long[]) o1, (long[]) o2);
}
if (o1 instanceof short[] && o2 instanceof short[]) {
return Arrays.equals((short[]) o1, (short[]) o2);
}
}
return false;
}
/**
* Return as hash code for the given object; typically the value of
* <code>{@link Object#hashCode()}</code>. If the object is an array,
* this method will delegate to any of the <code>nullSafeHashCode</code>
* methods for arrays in this class. If the object is <code>null</code>,
* this method returns 0.
*
* @param obj the object for which to generate a hash code.
* @return the hash code, or {@code 0} if the object is null.
* @see #nullSafeHashCode(Object...)
* @see #nullSafeHashCode(boolean[])
* @see #nullSafeHashCode(byte[])
* @see #nullSafeHashCode(char[])
* @see #nullSafeHashCode(double[])
* @see #nullSafeHashCode(float[])
* @see #nullSafeHashCode(int[])
* @see #nullSafeHashCode(long[])
* @see #nullSafeHashCode(short[])
*/
public static int nullSafeHashCode(Object obj) {
if (obj == null) {
return 0;
}
if (obj.getClass().isArray()) {
if (obj instanceof Object[]) {
return nullSafeHashCode((Object[]) obj);
}
if (obj instanceof boolean[]) {
return nullSafeHashCode((boolean[]) obj);
}
if (obj instanceof byte[]) {
return nullSafeHashCode((byte[]) obj);
}
if (obj instanceof char[]) {
return nullSafeHashCode((char[]) obj);
}
if (obj instanceof double[]) {
return nullSafeHashCode((double[]) obj);
}
if (obj instanceof float[]) {
return nullSafeHashCode((float[]) obj);
}
if (obj instanceof int[]) {
return nullSafeHashCode((int[]) obj);
}
if (obj instanceof long[]) {
return nullSafeHashCode((long[]) obj);
}
if (obj instanceof short[]) {
return nullSafeHashCode((short[]) obj);
}
}
return obj.hashCode();
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the array for which to generate a hash code.
* @return the array's hash code
*/
public static int nullSafeHashCode(Object... array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + nullSafeHashCode(array[i]);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the boolean array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(boolean[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + hashCode(array[i]);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the byte array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(byte[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + array[i];
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the char array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(char[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + array[i];
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the double array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(double[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + hashCode(array[i]);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the float array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(float[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + hashCode(array[i]);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the int array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(int[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + array[i];
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the long array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(long[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + hashCode(array[i]);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array.
* If <code>array</code> is <code>null</code>, this method returns 0.
*
* @param array the short array to hash
* @return the generated hash code
*/
public static int nullSafeHashCode(short[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
int arraySize = array.length;
for (int i = 0; i < arraySize; i++) {
hash = MULTIPLIER * hash + array[i];
}
return hash;
}
}