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.language.bean;
018    
019    import org.apache.camel.Exchange;
020    import org.apache.camel.Expression;
021    import org.apache.camel.Predicate;
022    import org.apache.camel.builder.PredicateBuilder;
023    import org.apache.camel.spi.Language;
024    import org.apache.camel.util.ObjectHelper;
025    
026    /**
027     * A <a href="http://activemq.apache.org/camel/bean-language.html>bean language</a>
028     * which uses a simple text notation to invoke methods on beans to evaluate predicates or expressions<p/>
029     * <p/>
030     * The notation is essentially <code>beanName.methodName</code> which is then invoked using the
031     * beanName to lookup in the <a href="http://activemq.apache.org/camel/registry.html>registry</a>
032     * then the method is invoked to evaluate the expression using the
033     * <a href="http://activemq.apache.org/camel/bean-integration.html>bean integration</a> to bind the
034     * {@link Exchange} to the method arguments.
035     *
036     * @version $Revision: 35332 $
037     */
038    public class BeanLanguage implements Language {
039        public Predicate<Exchange> createPredicate(String expression) {
040            return PredicateBuilder.toPredicate(createExpression(expression));
041        }
042    
043        public Expression<Exchange> createExpression(String expression) {
044            ObjectHelper.notNull(expression, "expression");
045    
046            int idx = expression.lastIndexOf('.');
047            String beanName = expression;
048            String method = null;
049            if (idx > 0) {
050                beanName = expression.substring(0, idx);
051                method = expression.substring(idx + 1);
052            }
053            return new BeanExpression(beanName, method);
054        }
055    }