ObjectUtils.java
/*
* Copyright 2002-2023 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 org.springframework.util;
import java.lang.reflect.Array;
import java.net.URI;
import java.net.URL;
import java.time.temporal.Temporal;
import java.util.Arrays;
import java.util.Collection;
import java.util.Date;
import java.util.Locale;
import java.util.Map;
import java.util.Optional;
import java.util.StringJoiner;
import org.springframework.lang.Nullable;
/**
* Miscellaneous object utility methods.
*
* <p>Mainly for internal use within the framework.
*
* <p>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
* @since 19.03.2004
* @see ClassUtils
* @see CollectionUtils
* @see StringUtils
*/
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];
/**
* Return whether the given throwable is a checked exception:
* that is, neither a RuntimeException nor an Error.
* @param ex the throwable to check
* @return whether the throwable is a checked exception
* @see java.lang.Exception
* @see java.lang.RuntimeException
* @see java.lang.Error
*/
public static boolean isCheckedException(Throwable ex) {
return !(ex instanceof RuntimeException || ex instanceof Error);
}
/**
* Check whether the given exception is compatible with the specified
* exception types, as declared in a throws clause.
* @param ex the exception to check
* @param declaredExceptions the exception types declared in the throws clause
* @return whether the given exception is compatible
*/
public static boolean isCompatibleWithThrowsClause(Throwable ex, @Nullable Class<?>... declaredExceptions) {
if (!isCheckedException(ex)) {
return true;
}
if (declaredExceptions != null) {
for (Class<?> declaredException : declaredExceptions) {
if (declaredException.isInstance(ex)) {
return true;
}
}
}
return false;
}
/**
* 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.
* <p>This method supports the following object types.
* <ul>
* <li>{@code Optional}: considered empty if not {@link Optional#isPresent()}</li>
* <li>{@code Array}: considered empty if its length is zero</li>
* <li>{@link CharSequence}: considered empty if its length is zero</li>
* <li>{@link Collection}: delegates to {@link Collection#isEmpty()}</li>
* <li>{@link Map}: delegates to {@link Map#isEmpty()}</li>
* </ul>
* <p>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 <em>empty</em>
* @since 4.2
* @see Optional#isPresent()
* @see ObjectUtils#isEmpty(Object[])
* @see StringUtils#hasLength(CharSequence)
* @see CollectionUtils#isEmpty(java.util.Collection)
* @see CollectionUtils#isEmpty(java.util.Map)
*/
public static boolean isEmpty(@Nullable Object obj) {
if (obj == null) {
return true;
}
if (obj instanceof Optional<?> optional) {
return !optional.isPresent();
}
if (obj instanceof CharSequence charSequence) {
return charSequence.length() == 0;
}
if (obj.getClass().isArray()) {
return Array.getLength(obj) == 0;
}
if (obj instanceof Collection<?> collection) {
return collection.isEmpty();
}
if (obj instanceof Map<?, ?> map) {
return map.isEmpty();
}
// else
return false;
}
/**
* Unwrap the given object which is potentially a {@link java.util.Optional}.
* @param obj the candidate object
* @return either the value held within the {@code Optional}, {@code null}
* if the {@code Optional} is empty, or simply the given object as-is
* @since 5.0
*/
@Nullable
public static Object unwrapOptional(@Nullable Object obj) {
if (obj instanceof Optional<?> optional) {
if (!optional.isPresent()) {
return null;
}
Object result = optional.get();
Assert.isTrue(!(result instanceof Optional), "Multi-level Optional usage not supported");
return result;
}
return obj;
}
/**
* 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(@Nullable Object[] array, Object element) {
if (array == null) {
return false;
}
for (Object arrayEle : array) {
if (nullSafeEquals(arrayEle, element)) {
return true;
}
}
return false;
}
/**
* Check whether the given array of enum constants contains a constant with the given name,
* ignoring case when determining a match.
* @param enumValues the enum values to check, typically obtained via {@code MyEnum.values()}
* @param constant the constant name to find (must not be null or empty string)
* @return whether the constant has been found in the given array
*/
public static boolean containsConstant(Enum<?>[] enumValues, String constant) {
return containsConstant(enumValues, constant, false);
}
/**
* Check whether the given array of enum constants contains a constant with the given name.
* @param enumValues the enum values to check, typically obtained via {@code MyEnum.values()}
* @param constant the constant name to find (must not be null or empty string)
* @param caseSensitive whether case is significant in determining a match
* @return whether the constant has been found in the given array
*/
public static boolean containsConstant(Enum<?>[] enumValues, String constant, boolean caseSensitive) {
for (Enum<?> candidate : enumValues) {
if (caseSensitive ? candidate.toString().equals(constant) :
candidate.toString().equalsIgnoreCase(constant)) {
return true;
}
}
return false;
}
/**
* Case insensitive alternative to {@link Enum#valueOf(Class, String)}.
* @param <E> the concrete Enum type
* @param enumValues the array of all Enum constants in question, usually per {@code Enum.values()}
* @param constant the constant to get the enum value of
* @throws IllegalArgumentException if the given constant is not found in the given array
* of enum values. Use {@link #containsConstant(Enum[], String)} as a guard to avoid this exception.
*/
public static <E extends Enum<?>> E caseInsensitiveValueOf(E[] enumValues, String constant) {
for (E candidate : enumValues) {
if (candidate.toString().equalsIgnoreCase(constant)) {
return candidate;
}
}
throw new IllegalArgumentException("Constant [" + constant + "] does not exist in enum type " +
enumValues.getClass().getComponentType().getName());
}
/**
* Append the given object to the given array, returning a new array
* consisting of the input array contents plus the given object.
* @param array the array to append to (can be {@code null})
* @param obj the object to append
* @return the new array (of the same component type; never {@code null})
*/
public static <A, O extends A> A[] addObjectToArray(@Nullable A[] array, @Nullable O obj) {
return addObjectToArray(array, obj, (array != null ? array.length : 0));
}
/**
* Add the given object to the given array at the specified position, returning
* a new array consisting of the input array contents plus the given object.
* @param array the array to add to (can be {@code null})
* @param obj the object to append
* @param position the position at which to add the object
* @return the new array (of the same component type; never {@code null})
* @since 6.0
*/
public static <A, O extends A> A[] addObjectToArray(@Nullable A[] array, @Nullable O obj, int position) {
Class<?> componentType = Object.class;
if (array != null) {
componentType = array.getClass().getComponentType();
}
else if (obj != null) {
componentType = obj.getClass();
}
int newArrayLength = (array != null ? array.length + 1 : 1);
@SuppressWarnings("unchecked")
A[] newArray = (A[]) Array.newInstance(componentType, newArrayLength);
if (array != null) {
System.arraycopy(array, 0, newArray, 0, position);
System.arraycopy(array, position, newArray, position + 1, array.length - position);
}
newArray[position] = obj;
return newArray;
}
/**
* Convert the given array (which may be a primitive array) to an
* object array (if necessary of primitive wrapper objects).
* <p>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[] objects) {
return objects;
}
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;
}
//---------------------------------------------------------------------
// 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}.
* <p>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(@Nullable Object o1, @Nullable 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[] objects1 && o2 instanceof Object[] objects2) {
return Arrays.equals(objects1, objects2);
}
if (o1 instanceof boolean[] booleans1 && o2 instanceof boolean[] booleans2) {
return Arrays.equals(booleans1, booleans2);
}
if (o1 instanceof byte[] bytes1 && o2 instanceof byte[] bytes2) {
return Arrays.equals(bytes1, bytes2);
}
if (o1 instanceof char[] chars1 && o2 instanceof char[] chars2) {
return Arrays.equals(chars1, chars2);
}
if (o1 instanceof double[] doubles1 && o2 instanceof double[] doubles2) {
return Arrays.equals(doubles1, doubles2);
}
if (o1 instanceof float[] floats1 && o2 instanceof float[] floats2) {
return Arrays.equals(floats1, floats2);
}
if (o1 instanceof int[] ints1 && o2 instanceof int[] ints2) {
return Arrays.equals(ints1, ints2);
}
if (o1 instanceof long[] longs1 && o2 instanceof long[] longs2) {
return Arrays.equals(longs1, longs2);
}
if (o1 instanceof short[] shorts1 && o2 instanceof short[] shorts2) {
return Arrays.equals(shorts1, shorts2);
}
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(@Nullable Object obj) {
if (obj == null) {
return 0;
}
if (obj.getClass().isArray()) {
if (obj instanceof Object[] objects) {
return nullSafeHashCode(objects);
}
if (obj instanceof boolean[] booleans) {
return nullSafeHashCode(booleans);
}
if (obj instanceof byte[] bytes) {
return nullSafeHashCode(bytes);
}
if (obj instanceof char[] chars) {
return nullSafeHashCode(chars);
}
if (obj instanceof double[] doubles) {
return nullSafeHashCode(doubles);
}
if (obj instanceof float[] floats) {
return nullSafeHashCode(floats);
}
if (obj instanceof int[] ints) {
return nullSafeHashCode(ints);
}
if (obj instanceof long[] longs) {
return nullSafeHashCode(longs);
}
if (obj instanceof short[] shorts) {
return nullSafeHashCode(shorts);
}
}
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(@Nullable 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(@Nullable 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(@Nullable 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(@Nullable 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(@Nullable 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(@Nullable 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(@Nullable 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(@Nullable 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(@Nullable 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 an object's overall identity.
* @param obj the object (may be {@code null})
* @return the object's identity as String representation,
* or an empty String if the object was {@code null}
*/
public static String identityToString(@Nullable Object obj) {
if (obj == null) {
return EMPTY_STRING;
}
return obj.getClass().getName() + "@" + getIdentityHexString(obj);
}
/**
* Return a hex String form of an object's identity hash code.
* @param obj the object
* @return the object's identity code in hex notation
*/
public static String getIdentityHexString(Object obj) {
return Integer.toHexString(System.identityHashCode(obj));
}
/**
* Return a content-based String representation if {@code obj} is
* not {@code null}; otherwise returns an empty String.
* <p>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.
* <p>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.
* <p>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}
* @see #nullSafeConciseToString(Object)
*/
public static String nullSafeToString(@Nullable Object obj) {
if (obj == null) {
return NULL_STRING;
}
if (obj instanceof String string) {
return string;
}
if (obj instanceof Object[] objects) {
return nullSafeToString(objects);
}
if (obj instanceof boolean[] booleans) {
return nullSafeToString(booleans);
}
if (obj instanceof byte[] bytes) {
return nullSafeToString(bytes);
}
if (obj instanceof char[] chars) {
return nullSafeToString(chars);
}
if (obj instanceof double[] doubles) {
return nullSafeToString(doubles);
}
if (obj instanceof float[] floats) {
return nullSafeToString(floats);
}
if (obj instanceof int[] ints) {
return nullSafeToString(ints);
}
if (obj instanceof long[] longs) {
return nullSafeToString(longs);
}
if (obj instanceof short[] shorts) {
return nullSafeToString(shorts);
}
String str = obj.toString();
return (str != null ? str : EMPTY_STRING);
}
/**
* Return a String representation of the contents of the specified array.
* <p>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.
* <p>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.
* <p>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.
* <p>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.
* <p>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.
* <p>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.
* <p>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.
* <p>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.
* <p>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();
}
/**
* Generate a null-safe, concise string representation of the supplied object
* as described below.
* <p>Favor this method over {@link #nullSafeToString(Object)} when you need
* the length of the generated string to be limited.
* <p>Returns:
* <ul>
* <li>{@code "null"} if {@code obj} is {@code null}</li>
* <li>{@linkplain Class#getName() Class name} if {@code obj} is a {@link Class}</li>
* <li>Potentially {@linkplain StringUtils#truncate(CharSequence) truncated string}
* if {@code obj} is a {@link String} or {@link CharSequence}</li>
* <li>Potentially {@linkplain StringUtils#truncate(CharSequence) truncated string}
* if {@code obj} is a <em>simple type</em> whose {@code toString()} method returns
* a non-null value.</li>
* <li>Otherwise, a string representation of the object's type name concatenated
* with {@code @} and a hex string form of the object's identity hash code</li>
* </ul>
* <p>In the context of this method, a <em>simple type</em> is any of the following:
* a primitive wrapper (excluding {@link Void}), an {@link Enum}, a {@link Number},
* a {@link Date}, a {@link Temporal}, a {@link URI}, a {@link URL}, or a {@link Locale}.
* @param obj the object to build a string representation for
* @return a concise string representation of the supplied object
* @since 5.3.27
* @see #nullSafeToString(Object)
* @see StringUtils#truncate(CharSequence)
*/
public static String nullSafeConciseToString(@Nullable Object obj) {
if (obj == null) {
return "null";
}
if (obj instanceof Class<?> clazz) {
return clazz.getName();
}
if (obj instanceof CharSequence charSequence) {
return StringUtils.truncate(charSequence);
}
Class<?> type = obj.getClass();
if (isSimpleValueType(type)) {
String str = obj.toString();
if (str != null) {
return StringUtils.truncate(str);
}
}
return type.getTypeName() + "@" + getIdentityHexString(obj);
}
/**
* Copy of {@link org.springframework.beans.BeanUtils#isSimpleValueType(Class)}.
* <p>Check if the given type represents a "simple" value type: a primitive or
* primitive wrapper, an enum, a String or other CharSequence, a Number, a
* Date, a Temporal, a URI, a URL, a Locale, or a Class.
* <p>{@code Void} and {@code void} are not considered simple value types.
* @param type the type to check
* @return whether the given type represents a "simple" value type
*/
private static boolean isSimpleValueType(Class<?> type) {
return (Void.class != type && void.class != type &&
(ClassUtils.isPrimitiveOrWrapper(type) ||
Enum.class.isAssignableFrom(type) ||
CharSequence.class.isAssignableFrom(type) ||
Number.class.isAssignableFrom(type) ||
Date.class.isAssignableFrom(type) ||
Temporal.class.isAssignableFrom(type) ||
URI.class == type ||
URL.class == type ||
Locale.class == type ||
Class.class == type));
}
}