001 /*
002 * Created on Oct 26, 2010
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
005 * the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
010 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
011 * specific language governing permissions and limitations under the License.
012 *
013 * Copyright @2010-2011 the original author or authors.
014 */
015 package org.fest.assertions.data;
016
017 import static org.fest.util.Objects.HASH_CODE_PRIME;
018
019 /**
020 * An index.
021 *
022 * @author Alex Ruiz
023 */
024 public class Index {
025
026 /** The value of this index. */
027 public final int value;
028
029 /**
030 * Creates a new <code>{@link Index}</code>.
031 * @param index the value of the index.
032 * @return the created <code>Index</code>.
033 * @throws IllegalArgumentException if the given value is negative.
034 */
035 public static Index atIndex(int index) {
036 if (index < 0) throw new IllegalArgumentException("The value of the index should not be negative");
037 return new Index(index);
038 }
039
040 private Index(int value) {
041 this.value = value;
042 }
043
044 @Override public boolean equals(Object obj) {
045 if (this == obj) return true;
046 if (obj == null) return false;
047 if (getClass() != obj.getClass()) return false;
048 Index other = (Index) obj;
049 return value == other.value;
050 }
051
052 @Override public int hashCode() {
053 int result = 1;
054 result = HASH_CODE_PRIME * result + value;
055 return result;
056 }
057
058 @Override public String toString() {
059 return String.format("%s[value=%d]", getClass().getSimpleName(), value);
060 }
061 }