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/*
* Copyright 2002-2016 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.ibankapp.base.util;
import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Map;
/**
* 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
* @see CollectionUtils
* @see StringUtils
* @since 19.03.2004
*/
public abstract class ObjectUtils {
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
* @return whether the given array is empty
* @see #isEmpty(Object)
*/
public static boolean isEmpty(Object[] array) {
return (array == null || array.length == 0);
}
/**
* Determine whether the given object is empty.
*
This method supports the following object types.
*
* - {@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 ObjectUtils#isEmpty(Object[])
* @see StringUtils#hasLength(CharSequence)
* @see StringUtils#isEmpty(Object)
* @see CollectionUtils#isEmpty(java.util.Collection)
* @see CollectionUtils#isEmpty(java.util.Map)
* @since 4.2
*/
@SuppressWarnings("rawtypes")
public static boolean isEmpty(Object obj) {
if (obj == null) {
return true;
}
if (obj.getClass().isArray()) {
return Array.getLength(obj) == 0;
}
if (obj instanceof CharSequence) {
return ((CharSequence) obj).length() == 0;
}
if (obj instanceof Collection) {
return ((Collection) obj).isEmpty();
}
if (obj instanceof Map) {
return ((Map) obj).isEmpty();
}
// else
return false;
}
/**
* 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 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);
}
String str = obj.toString();
return (str != null ? str : EMPTY_STRING);
}
}