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/*
* Copyright 2002-2005 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 org.springframework.util;
import java.lang.reflect.Array;
/**
* Miscellaneous object utility methods. Mainly for internal use within the
* framework; consider Jakarta's Commons Lang for a more comprehensive suite
* of object utilities.
*
* @author Juergen Hoeller
* @author Keith Donald
* @author Rod Johnson
* @since 19.03.2004
* @see org.apache.commons.lang.ObjectUtils
*/
public abstract class ObjectUtils {
/**
* Determine if the given objects are equal, returning true if both are null
* or false if only one is null.
* @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) {
return (o1 == o2 || (o1 != null && o1.equals(o2)));
}
/**
* Return a hex string form of an object's identity hash code.
* @param o the object
* @return the object's identity code in hex
*/
public static String getIdentityHexString(Object o) {
return Integer.toHexString(System.identityHashCode(o));
}
/**
* Return whether the given throwable is a checked exception,
* i.e. an Exception but not a RuntimeException.
* @param ex the throwable to check
* @return whether the throwable is a checked exception
* @see java.lang.Exception
* @see java.lang.RuntimeException
*/
public static boolean isCheckedException(Throwable ex) {
return (ex instanceof Exception) && (!(ex instanceof RuntimeException));
}
/**
* Check whether the given exception is compatible with the exceptions
* declared in a throws clause.
* @param ex the exception to checked
* @param declaredExceptions the exceptions declared in the throws clause
* @return whether the given exception is compatible
*/
public static boolean isCompatibleWithThrowsClause(Throwable ex, Class[] declaredExceptions) {
if (ex instanceof RuntimeException) {
return true;
}
if (declaredExceptions != null) {
for (int i = 0; i < declaredExceptions.length; i++) {
if (declaredExceptions[i].isAssignableFrom(ex.getClass())) {
return true;
}
}
}
return false;
}
/**
* Return whether the given array is empty: that is, null or of zero length.
* @param array the array to check
*/
public static boolean isEmpty(Object[] array) {
return (array == null || array.length == 0);
}
/**
* Convert a primitive array to an object array of primitive wrapper objects.
* @param primitiveArray the primitive array
* @return the object array
* @throws IllegalArgumentException if the parameter is not a primitive array
*/
public static Object[] toObjectArray(Object primitiveArray) {
if (primitiveArray == null) {
return new Object[0];
}
Class clazz = primitiveArray.getClass();
Assert.isTrue(clazz.isArray(),
"The specified parameter is not an array - it must be a primitive array.");
Assert.isTrue(clazz.getComponentType().isPrimitive(),
"The specified parameter is not a primitive array.");
int length = Array.getLength(primitiveArray);
if (length == 0) {
return new Object[0];
}
Class wrapperType = Array.get(primitiveArray, 0).getClass();
Object[] newArray = (Object[]) Array.newInstance(wrapperType, length);
for (int i = 0; i < length; i++) {
newArray[i] = Array.get(primitiveArray, i);
}
return newArray;
}
}