com.aspectran.core.util.ObjectUtils Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2023 The Aspectran Project
*
* 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 com.aspectran.core.util;
import com.aspectran.core.lang.Nullable;
import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Collection;
import java.util.Map;
import java.util.Optional;
import java.util.StringJoiner;
/**
* This class is a clone of org.springframework.util.ObjectUtils
*
* Miscellaneous object utility methods.
*/
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 = ", ";
private static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
/**
* Determine whether the given object is an array:
* either an Object array or a primitive array.
* @param obj the object to check
*/
public static boolean isArray(@Nullable Object obj) {
return (obj != null && obj.getClass().isArray());
}
/**
* 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(@Nullable Object[] array) {
return (array == null || array.length == 0);
}
/**
* Determine whether the given object is empty.
* This method supports the following object types.
*
* - {@code Optional}: considered empty if {@link Optional#empty()}
* - {@code Array}: considered empty if its length is zero
* - {@link CharSequence}: considered empty if its length is zero
* - {@link Collection}: delegates to {@link Collection#isEmpty()}
* - {@link Map}: delegates to {@link Map#isEmpty()}
*
* If the given object is non-null and not one of the aforementioned
* supported types, this method returns {@code false}.
*
* @param obj the object to check
* @return {@code true} if the object is {@code null} or empty
* @see Optional#isPresent()
* @see ObjectUtils#isEmpty(Object[])
* @see StringUtils#hasLength(CharSequence)
*/
@SuppressWarnings("rawtypes")
public static boolean isEmpty(@Nullable Object obj) {
if (obj == null) {
return true;
}
if (obj instanceof Optional) {
return !((Optional) obj).isPresent();
}
if (obj instanceof CharSequence) {
return ((CharSequence) obj).length() == 0;
}
if (obj.getClass().isArray()) {
return Array.getLength(obj) == 0;
}
if (obj instanceof Collection) {
return ((Collection) obj).isEmpty();
}
if (obj instanceof Map) {
return ((Map) obj).isEmpty();
}
// else
return false;
}
/**
* 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(@Nullable Object source) {
if (source instanceof Object[]) {
return (Object[]) source;
}
if (source == null) {
return EMPTY_OBJECT_ARRAY;
}
if (!source.getClass().isArray()) {
throw new IllegalArgumentException("Source is not an array: " + source);
}
int length = Array.getLength(source);
if (length == 0) {
return EMPTY_OBJECT_ARRAY;
}
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;
}
/**
* 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
*/
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
*/
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.
*
* @param obj the given object
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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.
*
* @param array the specified array
* @return a hash code value
*/
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 a content-based String representation if {@code obj} is
* not {@code null}; otherwise returns an empty String.
* Differs from {@link #nullSafeToString(Object)} in that it returns
* an empty String rather than "null" for a {@code null} value.
* @param obj the object to build a display String for
* @return a display String representation of {@code obj}
* @see #nullSafeToString(Object)
*/
public static String getDisplayString(@Nullable Object obj) {
if (obj == null) {
return EMPTY_STRING;
}
return nullSafeToString(obj);
}
/**
* Determine the class name for the given object.
*
Returns a {@code "null"} String if {@code obj} is {@code null}.
* @param obj the object to introspect (may be {@code null})
* @return the corresponding class name
*/
public static String nullSafeClassName(@Nullable Object obj) {
return (obj != null ? obj.getClass().getName() : NULL_STRING);
}
/**
* 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(@Nullable 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(@Nullable Object[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (Object o : array) {
stringJoiner.add(String.valueOf(o));
}
return stringJoiner.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 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(@Nullable boolean[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (boolean b : array) {
stringJoiner.add(String.valueOf(b));
}
return stringJoiner.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 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(@Nullable byte[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (byte b : array) {
stringJoiner.add(String.valueOf(b));
}
return stringJoiner.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 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(@Nullable char[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (char c : array) {
stringJoiner.add('\'' + String.valueOf(c) + '\'');
}
return stringJoiner.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 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(@Nullable double[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (double d : array) {
stringJoiner.add(String.valueOf(d));
}
return stringJoiner.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 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(@Nullable float[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (float f : array) {
stringJoiner.add(String.valueOf(f));
}
return stringJoiner.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 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(@Nullable int[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (int i : array) {
stringJoiner.add(String.valueOf(i));
}
return stringJoiner.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 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(@Nullable long[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (long l : array) {
stringJoiner.add(String.valueOf(l));
}
return stringJoiner.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 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(@Nullable short[] array) {
if (array == null) {
return NULL_STRING;
}
int length = array.length;
if (length == 0) {
return EMPTY_ARRAY;
}
StringJoiner stringJoiner = new StringJoiner(ARRAY_ELEMENT_SEPARATOR, ARRAY_START, ARRAY_END);
for (short s : array) {
stringJoiner.add(String.valueOf(s));
}
return stringJoiner.toString();
}
}