001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel;
018
019 import org.apache.camel.util.ObjectHelper;
020 import static org.apache.camel.util.ObjectHelper.notNull;
021
022 /**
023 * A helper class for working with predicates
024 *
025 * @version $Revision: 520261 $
026 */
027 public class Predicates {
028 /**
029 * A helper method to combine multiple predicates by a logical AND
030 */
031 public static <E extends Exchange> Predicate<E> and(final Predicate<E> left, final Predicate<E> right) {
032 notNull(left, "left");
033 notNull(right, "right");
034 return new Predicate<E>() {
035 public boolean evaluate(E exchange) {
036 return left.evaluate(exchange) && right.evaluate(exchange);
037 }
038 };
039 }
040
041 /**
042 * A helper method to combine multiple predicates by a logical OR
043 */
044 public static <E extends Exchange> Predicate<E> or(final Predicate<E> left, final Predicate<E> right) {
045 notNull(left, "left");
046 notNull(right, "right");
047 return new Predicate<E>() {
048 public boolean evaluate(E exchange) {
049 return left.evaluate(exchange) || right.evaluate(exchange);
050 }
051 };
052 }
053
054
055 public static <E extends Exchange> Predicate<E> isEqualTo(final Expression<E> left, final Expression<E> right) {
056 notNull(left, "left");
057 notNull(right, "right");
058
059 return new Predicate<E>() {
060 public boolean evaluate(E exchange) {
061 Object value1 = left.evaluate(exchange);
062 Object value2 = right.evaluate(exchange);
063 return ObjectHelper.equals(value1, value2);
064 }
065 };
066 }
067
068 public static <E extends Exchange> Predicate<E> isNotEqualTo(final Expression<E> left, final Expression<E> right) {
069 notNull(left, "left");
070 notNull(right, "right");
071
072 return new Predicate<E>() {
073 public boolean evaluate(E exchange) {
074 Object value1 = left.evaluate(exchange);
075 Object value2 = right.evaluate(exchange);
076 return !ObjectHelper.equals(value1, value2);
077 }
078 };
079 }
080
081 public static <E extends Exchange> Predicate<E> isLessThan(final Expression<E> left, final Expression<E> right) {
082 notNull(left, "left");
083 notNull(right, "right");
084
085 return new Predicate<E>() {
086 public boolean evaluate(E exchange) {
087 Object value1 = left.evaluate(exchange);
088 Object value2 = right.evaluate(exchange);
089 return ObjectHelper.compare(value1, value2) < 0;
090 }
091 };
092 }
093
094 public static <E extends Exchange> Predicate<E> isLessThanOrEqualTo(final Expression<E> left, final Expression<E> right) {
095 notNull(left, "left");
096 notNull(right, "right");
097
098 return new Predicate<E>() {
099 public boolean evaluate(E exchange) {
100 Object value1 = left.evaluate(exchange);
101 Object value2 = right.evaluate(exchange);
102 return ObjectHelper.compare(value1, value2) <= 0;
103 }
104 };
105 }
106
107 public static <E extends Exchange> Predicate<E> isGreaterThan(final Expression<E> left, final Expression<E> right) {
108 notNull(left, "left");
109 notNull(right, "right");
110
111 return new Predicate<E>() {
112 public boolean evaluate(E exchange) {
113 Object value1 = left.evaluate(exchange);
114 Object value2 = right.evaluate(exchange);
115 return ObjectHelper.compare(value1, value2) > 0;
116 }
117 };
118 }
119
120 public static <E extends Exchange> Predicate<E> isGreaterThanOrEqualTo(final Expression<E> left, final Expression<E> right) {
121 notNull(left, "left");
122 notNull(right, "right");
123
124 return new Predicate<E>() {
125 public boolean evaluate(E exchange) {
126 Object value1 = left.evaluate(exchange);
127 Object value2 = right.evaluate(exchange);
128 return ObjectHelper.compare(value1, value2) >= 0;
129 }
130 };
131 }
132 }