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.util;
018    
019    import org.apache.camel.Exchange;
020    import org.apache.camel.Expression;
021    import org.apache.camel.Predicate;
022    
023    public final class ExpressionToPredicateAdapter implements Predicate {
024        private final Expression expression;
025    
026        public ExpressionToPredicateAdapter(Expression expression) {
027            this.expression = expression;
028        }
029    
030        public boolean matches(Exchange exchange) {
031            if (expression instanceof Predicate) {
032                return ((Predicate) expression).matches(exchange);
033            } else {
034                Object value = expression.evaluate(exchange, Object.class);
035                return ObjectHelper.evaluateValuePredicate(value);
036            }
037        }
038    
039        @Override
040        public String toString() {
041            return expression.toString();
042        }
043    
044        /**
045         * Converts the given expression into an {@link Predicate}
046         */
047        public static Predicate toPredicate(final Expression expression) {
048            return new ExpressionToPredicateAdapter(expression);
049        }
050        
051    }