com.gitee.l0km.common.spring.util.ObjectUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2021 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
*
* https://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 com.gitee.l0km.common.spring.util;
import java.util.Arrays;
import com.google.common.base.Joiner;
import com.google.common.collect.Iterables;
import static com.gitee.l0km.common.spring.util.StringUtils.STRING_VALUEOF_FUN;
/**
* 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
* @author Sam Brannen
*/
public abstract class ObjectUtils {
private static final int INITIAL_HASH = 7;
private static final int MULTIPLIER = 31;
private static final String EMPTY_STRING = "";
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
* @see #isEmpty(Object)
*/
public static boolean isEmpty(Object[] array) {
return (array == null || array.length == 0);
}
/**
* Check whether the given array contains the given element.
* @param array the array to check (may be {@code null},
* in which case the return value will always be {@code false})
* @param element the element to check for
* @return whether the element has been found in the given array
*/
public static boolean containsElement(Object[] array, Object element) {
if (array == null) {
return false;
}
for (Object arrayEle : array) {
if (nullSafeEquals(arrayEle, element)) {
return true;
}
}
return false;
}
//---------------------------------------------------------------------
// 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 Object#equals(Object)
* @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()) {
return arrayEquals(o1, o2);
}
return false;
}
/**
* Compare the given arrays with {@code Arrays.equals}, performing an equality
* check based on the array elements rather than the array reference.
* @param o1 first array to compare
* @param o2 second array to compare
* @return whether the given objects are equal
* @see #nullSafeEquals(Object, Object)
* @see java.util.Arrays#equals
*/
private static boolean arrayEquals(Object o1, Object o2) {
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 Object#hashCode()
* @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 + Boolean.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 + Double.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 + Float.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 + Long.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;
}
//---------------------------------------------------------------------
// 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 a {@code "null"} String 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);
}
String str = obj.toString();
return (str != null ? str : EMPTY_STRING);
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
/**
* 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 a {@code "null"} String 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;
}
return ARRAY_START + Joiner.on(ARRAY_ELEMENT_SEPARATOR).join(Iterables.transform(Arrays.asList(array), STRING_VALUEOF_FUN))+ARRAY_END;
}
}