/**
* 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.component.bean;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import org.apache.camel.CamelContext;
import org.apache.camel.Expression;
import org.apache.camel.Predicate;
import org.apache.camel.language.LanguageAnnotation;
import org.apache.camel.spi.Language;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.util.PredicateToExpressionAdapter;
/**
* Default implementation of the {@link AnnotationExpressionFactory}.
*
* @version
*/
public class DefaultAnnotationExpressionFactory implements AnnotationExpressionFactory {
public Expression createExpression(CamelContext camelContext, Annotation annotation, LanguageAnnotation languageAnnotation, Class<?> expressionReturnType) {
String languageName = languageAnnotation.language();
if (languageName == null) {
throw new IllegalArgumentException("Cannot determine the language from the annotation: " + annotation);
}
Language language = camelContext.resolveLanguage(languageName);
if (language == null) {
throw new IllegalArgumentException("Cannot find the language: " + languageName + " on the classpath");
}
String expression = getExpressionFromAnnotation(annotation);
if (expressionReturnType == Boolean.class || expressionReturnType == boolean.class) {
Predicate predicate = language.createPredicate(expression);
return PredicateToExpressionAdapter.toExpression(predicate);
} else {
return language.createExpression(expression);
}
}
protected String getExpressionFromAnnotation(Annotation annotation) {
Object value = getAnnotationObjectValue(annotation, "value");
if (value == null) {
throw new IllegalArgumentException("Cannot determine the expression from the annotation: " + annotation);
}
return value.toString();
}
/**
* @param annotation The annotation to get the value of
* @param methodName The annotation name
* @return The value of the annotation
*/
protected Object getAnnotationObjectValue(Annotation annotation, String methodName) {
try {
Method method = annotation.getClass().getMethod(methodName);
Object value = ObjectHelper.invokeMethod(method, annotation);
return value;
} catch (NoSuchMethodException e) {
throw new IllegalArgumentException("Cannot determine the Object value of the annotation: " + annotation
+ " as it does not have the method: " + methodName + "() method", e);
}
}
}