/*
* Copyright 2002-2009 the original author or authors.
*
* Licensed 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.springframework.transaction.annotation;
import java.io.Serializable;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;
import org.springframework.transaction.interceptor.AbstractFallbackTransactionAttributeSource;
import org.springframework.transaction.interceptor.TransactionAttribute;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* Implementation of the
* {@link org.springframework.transaction.interceptor.TransactionAttributeSource}
* interface for working with transaction metadata in JDK 1.5+ annotation format.
*
* <p>This class reads Spring's JDK 1.5+ {@link Transactional} annotation and
* exposes corresponding transaction attributes to Spring's transaction infrastructure.
* Also supports EJB3's {@link javax.ejb.TransactionAttribute} annotation (if present).
* This class may also serve as base class for a custom TransactionAttributeSource,
* or get customized through {@link TransactionAnnotationParser} strategies.
*
* @author Colin Sampaleanu
* @author Juergen Hoeller
* @since 1.2
* @see Transactional
* @see TransactionAnnotationParser
* @see SpringTransactionAnnotationParser
* @see Ejb3TransactionAnnotationParser
* @see org.springframework.transaction.interceptor.TransactionInterceptor#setTransactionAttributeSource
* @see org.springframework.transaction.interceptor.TransactionProxyFactoryBean#setTransactionAttributeSource
*/
public class AnnotationTransactionAttributeSource extends AbstractFallbackTransactionAttributeSource
implements Serializable {
private static final boolean ejb3Present = ClassUtils.isPresent(
"javax.ejb.TransactionAttribute", AnnotationTransactionAttributeSource.class.getClassLoader());
private final boolean publicMethodsOnly;
private final Set<TransactionAnnotationParser> annotationParsers;
/**
* Create a default AnnotationTransactionAttributeSource, supporting
* public methods that carry the <code>Transactional</code> annotation
* or the EJB3 {@link javax.ejb.TransactionAttribute} annotation.
*/
public AnnotationTransactionAttributeSource() {
this(true);
}
/**
* Create a custom AnnotationTransactionAttributeSource, supporting
* public methods that carry the <code>Transactional</code> annotation
* or the EJB3 {@link javax.ejb.TransactionAttribute} annotation.
* @param publicMethodsOnly whether to support public methods that carry
* the <code>Transactional</code> annotation only (typically for use
* with proxy-based AOP), or protected/private methods as well
* (typically used with AspectJ class weaving)
*/
public AnnotationTransactionAttributeSource(boolean publicMethodsOnly) {
this.publicMethodsOnly = publicMethodsOnly;
this.annotationParsers = new LinkedHashSet<TransactionAnnotationParser>(2);
this.annotationParsers.add(new SpringTransactionAnnotationParser());
if (ejb3Present) {
this.annotationParsers.add(new Ejb3TransactionAnnotationParser());
}
}
/**
* Create a custom AnnotationTransactionAttributeSource.
* @param annotationParser the TransactionAnnotationParser to use
*/
public AnnotationTransactionAttributeSource(TransactionAnnotationParser annotationParser) {
this.publicMethodsOnly = true;
Assert.notNull(annotationParser, "TransactionAnnotationParser must not be null");
this.annotationParsers = Collections.singleton(annotationParser);
}
/**
* Create a custom AnnotationTransactionAttributeSource.
* @param annotationParsers the TransactionAnnotationParsers to use
*/
public AnnotationTransactionAttributeSource(Set<TransactionAnnotationParser> annotationParsers) {
this.publicMethodsOnly = true;
Assert.notEmpty(annotationParsers, "At least one TransactionAnnotationParser needs to be specified");
this.annotationParsers = annotationParsers;
}
@Override
protected TransactionAttribute findTransactionAttribute(Method method) {
return determineTransactionAttribute(method);
}
@Override
protected TransactionAttribute findTransactionAttribute(Class clazz) {
return determineTransactionAttribute(clazz);
}
/**
* Determine the transaction attribute for the given method or class.
* <p>This implementation delegates to configured
* {@link TransactionAnnotationParser TransactionAnnotationParsers}
* for parsing known annotations into Spring's metadata attribute class.
* Returns <code>null</code> if it's not transactional.
* <p>Can be overridden to support custom annotations that carry transaction metadata.
* @param ae the annotated method or class
* @return TransactionAttribute the configured transaction attribute,
* or <code>null</code> if none was found
*/
protected TransactionAttribute determineTransactionAttribute(AnnotatedElement ae) {
for (TransactionAnnotationParser annotationParser : this.annotationParsers) {
TransactionAttribute attr = annotationParser.parseTransactionAnnotation(ae);
if (attr != null) {
return attr;
}
}
return null;
}
/**
* By default, only public methods can be made transactional.
*/
@Override
protected boolean allowPublicMethodsOnly() {
return this.publicMethodsOnly;
}
}