/*
* 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.servicemix.bean.support;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.servicemix.bean.Content;
import org.apache.servicemix.bean.Operation;
import org.apache.servicemix.bean.Property;
import org.apache.servicemix.bean.XPath;
import org.apache.servicemix.components.util.MessageHelper;
import org.apache.servicemix.expression.Expression;
import org.apache.servicemix.expression.JAXPStringXPathExpression;
import org.apache.servicemix.expression.PropertyExpression;
import org.apache.servicemix.jbi.messaging.PojoMarshaler;
import javax.jbi.messaging.MessageExchange;
import javax.jbi.messaging.MessagingException;
import javax.jbi.messaging.NormalizedMessage;
import javax.xml.namespace.QName;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* Represents the metadata about a bean type created via a combination of introspection and annotations together with some
* useful sensible defaults
*
* @version $Revision: $
*/
public class BeanInfo {
private static final Log log = LogFactory.getLog(BeanInfo.class);
private Class type;
private MethodInvocationStrategy strategy;
private Map<String, MethodInfo> operations = new ConcurrentHashMap<String, MethodInfo>();
private MethodInfo defaultExpression;
public BeanInfo(Class type, MethodInvocationStrategy strategy) {
this.type = type;
this.strategy = strategy;
introspect(type);
if (operations.size() == 1) {
Collection<MethodInfo> methodInfos = operations.values();
for (MethodInfo methodInfo : methodInfos) {
defaultExpression = methodInfo;
}
}
}
public MethodInvocation createInvocation(Object pojo, MessageExchange messageExchange) throws MessagingException {
QName operation = messageExchange.getOperation();
MethodInfo methodInfo = null;
if (operation == null) {
methodInfo = defaultExpression;
}
else {
methodInfo = operations.get(operation.getLocalPart());
}
if (methodInfo != null) {
return methodInfo.createMethodInvocation(pojo, messageExchange);
}
return null;
}
protected void introspect(Class type) {
Method[] methods = type.getDeclaredMethods();
for (Method method : methods) {
introspect(type, method);
}
Class superclass = type.getSuperclass();
if (superclass != null && !superclass.equals(Object.class)) {
introspect(superclass);
}
}
protected void introspect(Class type, Method method) {
Class[] parameterTypes = method.getParameterTypes();
Annotation[][] parameterAnnotations = method.getParameterAnnotations();
final Expression[] parameterExpressions = new Expression[parameterTypes.length];
for (int i = 0; i < parameterTypes.length; i++) {
Class parameterType = parameterTypes[i];
Expression expression = createParameterUnmarshalExpression(type, method, parameterType, parameterAnnotations[i]);
if (expression == null) {
if (log.isDebugEnabled()) {
log.debug("No expression available for method: " + method.toString() + " parameter: " + i + " so ignoring method");
}
return;
}
parameterExpressions[i] = expression;
}
// now lets add the method to the repository
String opName = method.getName();
if (method.getAnnotation(Operation.class) != null) {
String name = method.getAnnotation(Operation.class).name();
if (name != null && name.length() > 0) {
opName = name;
}
}
Expression parametersExpression = createMethodParametersExpression(parameterExpressions);
operations.put(opName, new MethodInfo(type, method, parametersExpression));
}
protected Expression createMethodParametersExpression(final Expression[] parameterExpressions) {
return new Expression() {
public Object evaluate(MessageExchange messageExchange, NormalizedMessage normalizedMessage) throws MessagingException {
Object[] answer = new Object[parameterExpressions.length];
for (int i = 0; i < parameterExpressions.length; i++) {
Expression parameterExpression = parameterExpressions[i];
answer[i] = parameterExpression.evaluate(messageExchange, normalizedMessage);
}
return answer;
}
};
}
/**
* Creates an expression for the given parameter type if the parameter can be mapped automatically or null
* if the parameter cannot be mapped due to unsufficient annotations or not fitting with the default type conventions.
*/
protected Expression createParameterUnmarshalExpression(Class type, Method method, Class parameterType, Annotation[] parameterAnnotation) {
// TODO look for a parameter annotation that converts into an expression
for (Annotation annotation : parameterAnnotation) {
Expression answer = createParameterUnmarshalExpressionForAnnotation(type, method, parameterType, annotation);
if (answer != null) {
return answer;
}
}
return strategy.getDefaultParameterTypeExpression(parameterType);
}
protected Expression createParameterUnmarshalExpressionForAnnotation(Class type, Method method, Class parameterType, Annotation annotation) {
if (annotation instanceof Property) {
Property propertyAnnotation = (Property) annotation;
return new PropertyExpression(propertyAnnotation.name());
}
else if (annotation instanceof Content) {
Content content = (Content) annotation;
final PojoMarshaler marshaller = newInstance(content);
return createContentExpression(marshaller);
}
else if (annotation instanceof XPath) {
XPath xpathAnnotation = (XPath) annotation;
return new JAXPStringXPathExpression(xpathAnnotation.xpath());
}
return null;
}
protected Expression createContentExpression(final PojoMarshaler marshaller) {
return new Expression() {
public Object evaluate(MessageExchange exchange, NormalizedMessage message) throws MessagingException {
return MessageHelper.getBody(message, marshaller);
}
};
}
protected PojoMarshaler newInstance(Content content) {
try {
return content.marshalType().newInstance();
}
catch (InstantiationException e) {
throw new RuntimeException(e);
}
catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
}