001/* 002 * Copyright 2002-2018 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.support; 018 019import java.lang.reflect.UndeclaredThrowableException; 020 021import org.apache.commons.logging.Log; 022import org.apache.commons.logging.LogFactory; 023 024import org.springframework.beans.factory.InitializingBean; 025import org.springframework.transaction.PlatformTransactionManager; 026import org.springframework.transaction.TransactionDefinition; 027import org.springframework.transaction.TransactionException; 028import org.springframework.transaction.TransactionStatus; 029import org.springframework.transaction.TransactionSystemException; 030 031/** 032 * Template class that simplifies programmatic transaction demarcation and 033 * transaction exception handling. 034 * 035 * <p>The central method is {@link #execute}, supporting transactional code that 036 * implements the {@link TransactionCallback} interface. This template handles 037 * the transaction lifecycle and possible exceptions such that neither the 038 * TransactionCallback implementation nor the calling code needs to explicitly 039 * handle transactions. 040 * 041 * <p>Typical usage: Allows for writing low-level data access objects that use 042 * resources such as JDBC DataSources but are not transaction-aware themselves. 043 * Instead, they can implicitly participate in transactions handled by higher-level 044 * application services utilizing this class, making calls to the low-level 045 * services via an inner-class callback object. 046 * 047 * <p>Can be used within a service implementation via direct instantiation with 048 * a transaction manager reference, or get prepared in an application context 049 * and passed to services as bean reference. Note: The transaction manager should 050 * always be configured as bean in the application context: in the first case given 051 * to the service directly, in the second case given to the prepared template. 052 * 053 * <p>Supports setting the propagation behavior and the isolation level by name, 054 * for convenient configuration in context definitions. 055 * 056 * @author Juergen Hoeller 057 * @since 17.03.2003 058 * @see #execute 059 * @see #setTransactionManager 060 * @see org.springframework.transaction.PlatformTransactionManager 061 */ 062@SuppressWarnings("serial") 063public class TransactionTemplate extends DefaultTransactionDefinition 064 implements TransactionOperations, InitializingBean { 065 066 /** Logger available to subclasses */ 067 protected final Log logger = LogFactory.getLog(getClass()); 068 069 private PlatformTransactionManager transactionManager; 070 071 072 /** 073 * Construct a new TransactionTemplate for bean usage. 074 * <p>Note: The PlatformTransactionManager needs to be set before 075 * any {@code execute} calls. 076 * @see #setTransactionManager 077 */ 078 public TransactionTemplate() { 079 } 080 081 /** 082 * Construct a new TransactionTemplate using the given transaction manager. 083 * @param transactionManager the transaction management strategy to be used 084 */ 085 public TransactionTemplate(PlatformTransactionManager transactionManager) { 086 this.transactionManager = transactionManager; 087 } 088 089 /** 090 * Construct a new TransactionTemplate using the given transaction manager, 091 * taking its default settings from the given transaction definition. 092 * @param transactionManager the transaction management strategy to be used 093 * @param transactionDefinition the transaction definition to copy the 094 * default settings from. Local properties can still be set to change values. 095 */ 096 public TransactionTemplate(PlatformTransactionManager transactionManager, TransactionDefinition transactionDefinition) { 097 super(transactionDefinition); 098 this.transactionManager = transactionManager; 099 } 100 101 102 /** 103 * Set the transaction management strategy to be used. 104 */ 105 public void setTransactionManager(PlatformTransactionManager transactionManager) { 106 this.transactionManager = transactionManager; 107 } 108 109 /** 110 * Return the transaction management strategy to be used. 111 */ 112 public PlatformTransactionManager getTransactionManager() { 113 return this.transactionManager; 114 } 115 116 @Override 117 public void afterPropertiesSet() { 118 if (this.transactionManager == null) { 119 throw new IllegalArgumentException("Property 'transactionManager' is required"); 120 } 121 } 122 123 124 @Override 125 public <T> T execute(TransactionCallback<T> action) throws TransactionException { 126 if (this.transactionManager instanceof CallbackPreferringPlatformTransactionManager) { 127 return ((CallbackPreferringPlatformTransactionManager) this.transactionManager).execute(this, action); 128 } 129 else { 130 TransactionStatus status = this.transactionManager.getTransaction(this); 131 T result; 132 try { 133 result = action.doInTransaction(status); 134 } 135 catch (RuntimeException ex) { 136 // Transactional code threw application exception -> rollback 137 rollbackOnException(status, ex); 138 throw ex; 139 } 140 catch (Error err) { 141 // Transactional code threw error -> rollback 142 rollbackOnException(status, err); 143 throw err; 144 } 145 catch (Throwable ex) { 146 // Transactional code threw unexpected exception -> rollback 147 rollbackOnException(status, ex); 148 throw new UndeclaredThrowableException(ex, "TransactionCallback threw undeclared checked exception"); 149 } 150 this.transactionManager.commit(status); 151 return result; 152 } 153 } 154 155 /** 156 * Perform a rollback, handling rollback exceptions properly. 157 * @param status object representing the transaction 158 * @param ex the thrown application exception or error 159 * @throws TransactionException in case of a rollback error 160 */ 161 private void rollbackOnException(TransactionStatus status, Throwable ex) throws TransactionException { 162 logger.debug("Initiating transaction rollback on application exception", ex); 163 try { 164 this.transactionManager.rollback(status); 165 } 166 catch (TransactionSystemException ex2) { 167 logger.error("Application exception overridden by rollback exception", ex); 168 ex2.initApplicationException(ex); 169 throw ex2; 170 } 171 catch (RuntimeException ex2) { 172 logger.error("Application exception overridden by rollback exception", ex); 173 throw ex2; 174 } 175 catch (Error err) { 176 logger.error("Application exception overridden by rollback error", ex); 177 throw err; 178 } 179 } 180 181 182 @Override 183 public boolean equals(Object other) { 184 return (this == other || (super.equals(other) && (!(other instanceof TransactionTemplate) || 185 getTransactionManager() == ((TransactionTemplate) other).getTransactionManager()))); 186 } 187 188}