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.language.bean; 018 019import org.apache.camel.Expression; 020import org.apache.camel.IsSingleton; 021import org.apache.camel.Predicate; 022import org.apache.camel.spi.Language; 023import org.apache.camel.util.ExpressionToPredicateAdapter; 024import org.apache.camel.util.ObjectHelper; 025 026/** 027 * A <a href="http://camel.apache.org/bean-language.html">bean language</a> 028 * which uses a simple text notation to invoke methods on beans to evaluate predicates or expressions 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://camel.apache.org/registry.html>registry</a> 032 * then the method is invoked to evaluate the expression using the 033 * <a href="http://camel.apache.org/bean-integration.html">bean integration</a> to bind the 034 * {@link org.apache.camel.Exchange} to the method arguments. 035 * <p/> 036 * As of Camel 1.5 the bean language also supports invoking a provided bean by 037 * its classname or the bean itself. 038 * 039 * @version 040 */ 041public class BeanLanguage implements Language, IsSingleton { 042 043 /** 044 * Creates the expression based on the string syntax. 045 * 046 * @param expression the string syntax <tt>beanRef.methodName</tt> where methodName can be omitted 047 * @return the expression 048 */ 049 public static Expression bean(String expression) { 050 BeanLanguage language = new BeanLanguage(); 051 return language.createExpression(expression); 052 } 053 054 /** 055 * Creates the expression for invoking the bean type. 056 * 057 * @param beanType the bean type to invoke 058 * @param method optional name of method to invoke for instance to avoid ambiguity 059 * @return the expression 060 */ 061 public static Expression bean(Class<?> beanType, String method) { 062 Object bean = ObjectHelper.newInstance(beanType); 063 return bean(bean, method); 064 } 065 066 /** 067 * Creates the expression for invoking the bean type. 068 * 069 * @param bean the bean to invoke 070 * @param method optional name of method to invoke for instance to avoid ambiguity 071 * @return the expression 072 */ 073 public static Expression bean(Object bean, String method) { 074 BeanLanguage language = new BeanLanguage(); 075 return language.createExpression(bean, method); 076 } 077 078 public Predicate createPredicate(String expression) { 079 return ExpressionToPredicateAdapter.toPredicate(createExpression(expression)); 080 } 081 082 public Expression createExpression(String expression) { 083 ObjectHelper.notNull(expression, "expression"); 084 085 String beanName = expression; 086 String method = null; 087 088 // we support both the .method name and the ?method= syntax 089 // as the ?method= syntax is very common for the bean component 090 if (expression.contains("?method=")) { 091 beanName = ObjectHelper.before(expression, "?"); 092 method = ObjectHelper.after(expression, "?method="); 093 } else { 094 int idx = expression.indexOf('.'); 095 if (idx > 0) { 096 beanName = expression.substring(0, idx); 097 method = expression.substring(idx + 1); 098 } 099 } 100 101 return new BeanExpression(beanName, method); 102 } 103 104 public Expression createExpression(Object bean, String method) { 105 ObjectHelper.notNull(bean, "bean"); 106 return new BeanExpression(bean, method); 107 } 108 109 public boolean isSingleton() { 110 return true; 111 } 112}