goja.core.kits.ObjectKit Maven / Gradle / Ivy
/*
* Copyright 2002-2013 the original author or authors.
*
* 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 goja.core.kits;
import java.lang.reflect.Array;
import java.util.Arrays;
/**
* Miscellaneous object utility methods. Mainly for internal use within the framework.
*
* Thanks to Alex Ruiz for contributing several enhancements to this class!
*
* @author Juergen Hoeller
* @author Keith Donald
* @author Rod Johnson
* @author Rob Harrop
* @author Chris Beams
* @since 19.03.2004
*/
public abstract class ObjectKit {
private static final int INITIAL_HASH = 7;
private static final int MULTIPLIER = 31;
private static final String NULL_STRING = "null";
private static final String ARRAY_START = "{";
private static final String ARRAY_END = "}";
private static final String EMPTY_ARRAY = ARRAY_START + ARRAY_END;
private static final String ARRAY_ELEMENT_SEPARATOR = ", ";
/**
* Determine whether the given array is empty: i.e. {@code null} or of zero length.
*
* @param array the array to check
*/
public static boolean isEmpty(Object[] array) {
return (array == null || array.length == 0);
}
/**
* Convert the given array (which may be a primitive array) to an object array (if necessary of
* primitive wrapper objects).
A {@code null} source value will be converted to an empty Object
* array.
*
* @param source the (potentially primitive) array
* @return the corresponding object array (never {@code null})
* @throws IllegalArgumentException if the parameter is not an array
*/
public static Object[] toObjectArray(Object source) {
if (source instanceof Object[]) {
return (Object[]) source;
}
if (source == null) {
return new Object[0];
}
if (!source.getClass().isArray()) {
throw new IllegalArgumentException("Source is not an array: " + source);
}
int length = Array.getLength(source);
if (length == 0) {
return new Object[0];
}
Class wrapperType = Array.get(source, 0).getClass();
Object[] newArray = (Object[]) Array.newInstance(wrapperType, length);
for (int i = 0; i < length; i++) {
newArray[i] = Array.get(source, i);
}
return newArray;
}
//---------------------------------------------------------------------
// Convenience methods for content-based equality/hash-code handling
//---------------------------------------------------------------------
/**
* Determine if the given objects are equal, returning {@code true} if both are {@code null} or
* {@code false} if only one is {@code null}.
Compares arrays with {@code Arrays.equals},
* 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 Object#hashCode()}}. If
* the object is an array, this method will delegate to any of the {@code nullSafeHashCode}
* methods for arrays in this class. If the object is {@code null}, this method returns 0.
*
* @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} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(Object[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (Object element : array) {
hash = MULTIPLIER * hash + nullSafeHashCode(element);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(boolean[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (boolean element : array) {
hash = MULTIPLIER * hash + hashCode(element);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(byte[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (byte element : array) {
hash = MULTIPLIER * hash + element;
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(char[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (char element : array) {
hash = MULTIPLIER * hash + element;
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(double[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (double element : array) {
hash = MULTIPLIER * hash + hashCode(element);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(float[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (float element : array) {
hash = MULTIPLIER * hash + hashCode(element);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(int[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (int element : array) {
hash = MULTIPLIER * hash + element;
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(long[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (long element : array) {
hash = MULTIPLIER * hash + hashCode(element);
}
return hash;
}
/**
* Return a hash code based on the contents of the specified array. If {@code array} is {@code
* null}, this method returns 0.
*/
public static int nullSafeHashCode(short[] array) {
if (array == null) {
return 0;
}
int hash = INITIAL_HASH;
for (short element : array) {
hash = MULTIPLIER * hash + element;
}
return hash;
}
/**
* Return the same value as {@link Boolean#hashCode()}}.
*
* @see Boolean#hashCode()
*/
public static int hashCode(boolean bool) {
return (bool ? 1231 : 1237);
}
/**
* Return the same value as {@link Double#hashCode()}}.
*
* @see Double#hashCode()
*/
public static int hashCode(double dbl) {
return hashCode(Double.doubleToLongBits(dbl));
}
/**
* Return the same value as {@link Float#hashCode()}}.
*
* @see Float#hashCode()
*/
public static int hashCode(float flt) {
return Float.floatToIntBits(flt);
}
/**
* Return the same value as {@link Long#hashCode()}}.
*
* @see Long#hashCode()
*/
public static int hashCode(long lng) {
return (int) (lng ^ (lng >>> 32));
}
//---------------------------------------------------------------------
// Convenience methods for toString output
//---------------------------------------------------------------------
/**
* Return a String representation of the specified Object.
Builds a String representation of
* the contents in case of an array. Returns {@code "null"} if {@code obj} is {@code null}.
*
* @param obj the object to build a String representation for
* @return a String representation of {@code obj}
*/
public static String nullSafeToString(Object obj) {
if (obj == null) {
return NULL_STRING;
}
if (obj instanceof String) {
return (String) obj;
}
if (obj instanceof Object[]) {
return nullSafeToString((Object[]) obj);
}
if (obj instanceof boolean[]) {
return nullSafeToString((boolean[]) obj);
}
if (obj instanceof byte[]) {
return nullSafeToString((byte[]) obj);
}
if (obj instanceof char[]) {
return nullSafeToString((char[]) obj);
}
if (obj instanceof double[]) {
return nullSafeToString((double[]) obj);
}
if (obj instanceof float[]) {
return nullSafeToString((float[]) obj);
}
if (obj instanceof int[]) {
return nullSafeToString((int[]) obj);
}
if (obj instanceof long[]) {
return nullSafeToString((long[]) obj);
}
if (obj instanceof short[]) {
return nullSafeToString((short[]) obj);
}
return obj.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(Object[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(String.valueOf(array[i]));
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(boolean[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(array[i]);
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(byte[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(array[i]);
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(char[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append("'").append(array[i]).append("'");
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(double[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(array[i]);
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(float[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(array[i]);
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(int[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(array[i]);
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(long[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(array[i]);
}
sb.append(ARRAY_END);
return sb.toString();
}
/**
* Return a String representation of the contents of the specified array.
The String
* representation consists of a list of the array's elements, enclosed in curly braces ({@code
* "{}"}). Adjacent elements are separated by the characters {@code ", "} (a comma followed by a
* space). Returns {@code "null"} if {@code array} is {@code null}.
*
* @param array the array to build a String representation for
* @return a String representation of {@code array}
*/
public static String nullSafeToString(short[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (i == 0) {
sb.append(ARRAY_START);
} else {
sb.append(ARRAY_ELEMENT_SEPARATOR);
}
sb.append(array[i]);
}
sb.append(ARRAY_END);
return sb.toString();
}
}