001/* 002 * Copyright 2002-2019 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.transaction.interceptor; 018 019import java.lang.reflect.Method; 020 021import org.springframework.lang.Nullable; 022 023/** 024 * Strategy interface used by {@link TransactionInterceptor} for metadata retrieval. 025 * 026 * <p>Implementations know how to source transaction attributes, whether from configuration, 027 * metadata attributes at source level (such as Java 5 annotations), or anywhere else. 028 * 029 * @author Rod Johnson 030 * @author Juergen Hoeller 031 * @since 15.04.2003 032 * @see TransactionInterceptor#setTransactionAttributeSource 033 * @see TransactionProxyFactoryBean#setTransactionAttributeSource 034 * @see org.springframework.transaction.annotation.AnnotationTransactionAttributeSource 035 */ 036public interface TransactionAttributeSource { 037 038 /** 039 * Determine whether the given class is a candidate for transaction attributes 040 * in the metadata format of this {@code TransactionAttributeSource}. 041 * <p>If this method returns {@code false}, the methods on the given class 042 * will not get traversed for {@link #getTransactionAttribute} introspection. 043 * Returning {@code false} is therefore an optimization for non-affected 044 * classes, whereas {@code true} simply means that the class needs to get 045 * fully introspected for each method on the given class individually. 046 * @param targetClass the class to introspect 047 * @return {@code false} if the class is known to have no transaction 048 * attributes at class or method level; {@code true} otherwise. The default 049 * implementation returns {@code true}, leading to regular introspection. 050 * @since 5.2 051 */ 052 default boolean isCandidateClass(Class<?> targetClass) { 053 return true; 054 } 055 056 /** 057 * Return the transaction attribute for the given method, 058 * or {@code null} if the method is non-transactional. 059 * @param method the method to introspect 060 * @param targetClass the target class (may be {@code null}, 061 * in which case the declaring class of the method must be used) 062 * @return the matching transaction attribute, or {@code null} if none found 063 */ 064 @Nullable 065 TransactionAttribute getTransactionAttribute(Method method, @Nullable Class<?> targetClass); 066 067}