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 */
017package org.apache.camel.util;
018
019import org.apache.camel.Exchange;
020import org.apache.camel.Expression;
021import org.apache.camel.Predicate;
022
023/**
024 * To adapt {@link org.apache.camel.Expression} as a {@link Predicate}
025 */
026public final class ExpressionToPredicateAdapter implements Predicate {
027    private final Expression expression;
028
029    public ExpressionToPredicateAdapter(Expression expression) {
030        this.expression = expression;
031    }
032
033    public boolean matches(Exchange exchange) {
034        if (expression instanceof Predicate) {
035            return ((Predicate) expression).matches(exchange);
036        } else {
037            Object value = expression.evaluate(exchange, Object.class);
038            return ObjectHelper.evaluateValuePredicate(value);
039        }
040    }
041
042    @Override
043    public String toString() {
044        return expression.toString();
045    }
046
047    /**
048     * Converts the given expression into an {@link Predicate}
049     */
050    public static Predicate toPredicate(final Expression expression) {
051        return new ExpressionToPredicateAdapter(expression);
052    }
053    
054}