| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.commons.lang3.compare; |
| |
| import java.io.Serializable; |
| import java.util.Comparator; |
| |
| /** |
| * Compares Object's {@link Object#toString()} values. |
| * |
| * This class is stateless. |
| * |
| * @since 3.10 |
| */ |
| public final class ObjectToStringComparator implements Comparator<Object>, Serializable { |
| |
| /** |
| * Singleton instance. |
| * |
| * This class is stateless. |
| */ |
| public static final ObjectToStringComparator INSTANCE = new ObjectToStringComparator(); |
| |
| /** |
| * For {@link Serializable}. |
| */ |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public int compare(final Object o1, final Object o2) { |
| if (o1 == null && o2 == null) { |
| return 0; |
| } |
| if (o1 == null) { |
| return 1; |
| } |
| if (o2 == null) { |
| return -1; |
| } |
| final String string1 = o1.toString(); |
| final String string2 = o2.toString(); |
| // No guarantee that toString() returns a non-null value, despite what Spotbugs thinks. |
| if (string1 == null && string2 == null) { |
| return 0; |
| } |
| if (string1 == null) { |
| return 1; |
| } |
| if (string2 == null) { |
| return -1; |
| } |
| return string1.compareTo(string2); |
| } |
| } |