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The Core Camel Java DSL based router
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.camel.language.bean;
import org.apache.camel.Expression;
import org.apache.camel.IsSingleton;
import org.apache.camel.Predicate;
import org.apache.camel.spi.Language;
import org.apache.camel.util.ExpressionToPredicateAdapter;
import org.apache.camel.util.ObjectHelper;
/**
* A bean language
* which uses a simple text notation to invoke methods on beans to evaluate predicates or expressions
*
* The notation is essentially beanName.methodName
which is then invoked using the
* beanName to lookup in the bean integration to bind the
* {@link org.apache.camel.Exchange} to the method arguments.
*
* As of Camel 1.5 the bean language also supports invoking a provided bean by
* its classname or the bean itself.
*
* @version
*/
public class BeanLanguage implements Language, IsSingleton {
/**
* Creates the expression based on the string syntax.
*
* @param expression the string syntax beanRef.methodName where methodName can be omitted
* @return the expression
*/
public static Expression bean(String expression) {
BeanLanguage language = new BeanLanguage();
return language.createExpression(expression);
}
/**
* Creates the expression for invoking the bean type.
*
* @param beanType the bean type to invoke
* @param method optional name of method to invoke for instance to avoid ambiguity
* @return the expression
*/
public static Expression bean(Class beanType, String method) {
Object bean = ObjectHelper.newInstance(beanType);
return bean(bean, method);
}
/**
* Creates the expression for invoking the bean type.
*
* @param bean the bean to invoke
* @param method optional name of method to invoke for instance to avoid ambiguity
* @return the expression
*/
public static Expression bean(Object bean, String method) {
BeanLanguage language = new BeanLanguage();
return language.createExpression(bean, method);
}
public Predicate createPredicate(String expression) {
return ExpressionToPredicateAdapter.toPredicate(createExpression(expression));
}
public Expression createExpression(String expression) {
ObjectHelper.notNull(expression, "expression");
String beanName = expression;
String method = null;
// we support both the .method name and the ?method= syntax
// as the ?method= syntax is very common for the bean component
if (expression.contains("?method=")) {
beanName = ObjectHelper.before(expression, "?");
method = ObjectHelper.after(expression, "?method=");
} else {
//first check case :: because of my.own.Bean::method
int doubleColonIndex = expression.indexOf("::");
//need to check that not inside params
int beginOfParameterDeclaration = expression.indexOf("(");
if (doubleColonIndex > 0 && (expression.indexOf("(") < 0 || doubleColonIndex < beginOfParameterDeclaration)) {
beanName = expression.substring(0, doubleColonIndex);
method = expression.substring(doubleColonIndex + 2);
} else {
int idx = expression.indexOf('.');
if (idx > 0) {
beanName = expression.substring(0, idx);
method = expression.substring(idx + 1);
}
}
}
return new BeanExpression(beanName, method);
}
public Expression createExpression(Object bean, String method) {
ObjectHelper.notNull(bean, "bean");
return new BeanExpression(bean, method);
}
public boolean isSingleton() {
return true;
}
}