1/*
2 * Copyright (C) 2007 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect;
18
19import com.google.common.annotations.GwtCompatible;
20
21import java.io.Serializable;
22
23/**
24 * An ordering that uses the natural order of the string representation of the
25 * values.
26 */
27@GwtCompatible(serializable = true)
28final class UsingToStringOrdering
29    extends Ordering<Object> implements Serializable {
30  static final UsingToStringOrdering INSTANCE = new UsingToStringOrdering();
31
32  @Override public int compare(Object left, Object right) {
33    return left.toString().compareTo(right.toString());
34  }
35
36  // preserve singleton-ness, so equals() and hashCode() work correctly
37  private Object readResolve() {
38    return INSTANCE;
39  }
40
41  @Override public String toString() {
42    return "Ordering.usingToString()";
43  }
44
45  private UsingToStringOrdering() {}
46
47  private static final long serialVersionUID = 0;
48}
49