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; 025import org.apache.camel.util.StringHelper; 026 027/** 028 * A <a href="http://camel.apache.org/bean-language.html">bean language</a> 029 * which uses a simple text notation to invoke methods on beans to evaluate predicates or expressions 030 * <p/> 031 * The notation is essentially <code>beanName.methodName</code> which is then invoked using the 032 * beanName to lookup in the <a href="http://camel.apache.org/registry.html>registry</a> 033 * then the method is invoked to evaluate the expression using the 034 * <a href="http://camel.apache.org/bean-integration.html">bean integration</a> to bind the 035 * {@link org.apache.camel.Exchange} to the method arguments. 036 * <p/> 037 * As of Camel 1.5 the bean language also supports invoking a provided bean by 038 * its classname or the bean itself. 039 * 040 * @version 041 */ 042public class BeanLanguage implements Language, IsSingleton { 043 044 /** 045 * Creates the expression based on the string syntax. 046 * 047 * @param expression the string syntax <tt>beanRef.methodName</tt> where methodName can be omitted 048 * @return the expression 049 */ 050 public static Expression bean(String expression) { 051 BeanLanguage language = new BeanLanguage(); 052 return language.createExpression(expression); 053 } 054 055 /** 056 * Creates the expression for invoking the bean type. 057 * 058 * @param beanType the bean type to invoke 059 * @param method optional name of method to invoke for instance to avoid ambiguity 060 * @return the expression 061 */ 062 public static Expression bean(Class<?> beanType, String method) { 063 Object bean = ObjectHelper.newInstance(beanType); 064 return bean(bean, method); 065 } 066 067 /** 068 * Creates the expression for invoking the bean type. 069 * 070 * @param bean the bean to invoke 071 * @param method optional name of method to invoke for instance to avoid ambiguity 072 * @return the expression 073 */ 074 public static Expression bean(Object bean, String method) { 075 BeanLanguage language = new BeanLanguage(); 076 return language.createExpression(bean, method); 077 } 078 079 public Predicate createPredicate(String expression) { 080 return ExpressionToPredicateAdapter.toPredicate(createExpression(expression)); 081 } 082 083 public Expression createExpression(String expression) { 084 ObjectHelper.notNull(expression, "expression"); 085 086 String beanName = expression; 087 String method = null; 088 089 // we support both the .method name and the ?method= syntax 090 // as the ?method= syntax is very common for the bean component 091 if (expression.contains("?method=")) { 092 beanName = StringHelper.before(expression, "?"); 093 method = StringHelper.after(expression, "?method="); 094 } else { 095 //first check case :: because of my.own.Bean::method 096 int doubleColonIndex = expression.indexOf("::"); 097 //need to check that not inside params 098 int beginOfParameterDeclaration = expression.indexOf("("); 099 if (doubleColonIndex > 0 && (expression.indexOf("(") < 0 || doubleColonIndex < beginOfParameterDeclaration)) { 100 beanName = expression.substring(0, doubleColonIndex); 101 method = expression.substring(doubleColonIndex + 2); 102 } else { 103 int idx = expression.indexOf('.'); 104 if (idx > 0) { 105 beanName = expression.substring(0, idx); 106 method = expression.substring(idx + 1); 107 } 108 } 109 } 110 111 return new BeanExpression(beanName, method); 112 } 113 114 public Expression createExpression(Object bean, String method) { 115 ObjectHelper.notNull(bean, "bean"); 116 return new BeanExpression(bean, method); 117 } 118 119 public boolean isSingleton() { 120 return true; 121 } 122}