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.jca.cci.connection; 018 019import java.lang.reflect.InvocationHandler; 020import java.lang.reflect.InvocationTargetException; 021import java.lang.reflect.Method; 022import java.lang.reflect.Proxy; 023 024import javax.resource.ResourceException; 025import javax.resource.cci.Connection; 026import javax.resource.cci.ConnectionFactory; 027 028import org.springframework.lang.Nullable; 029 030/** 031 * Proxy for a target CCI {@link javax.resource.cci.ConnectionFactory}, adding 032 * awareness of Spring-managed transactions. Similar to a transactional JNDI 033 * ConnectionFactory as provided by a Java EE server. 034 * 035 * <p>Data access code that should remain unaware of Spring's data access support 036 * can work with this proxy to seamlessly participate in Spring-managed transactions. 037 * Note that the transaction manager, for example the {@link CciLocalTransactionManager}, 038 * still needs to work with underlying ConnectionFactory, <i>not</i> with this proxy. 039 * 040 * <p><b>Make sure that TransactionAwareConnectionFactoryProxy is the outermost 041 * ConnectionFactory of a chain of ConnectionFactory proxies/adapters.</b> 042 * TransactionAwareConnectionFactoryProxy can delegate either directly to the 043 * target connection pool or to some intermediate proxy/adapter like 044 * {@link ConnectionSpecConnectionFactoryAdapter}. 045 * 046 * <p>Delegates to {@link ConnectionFactoryUtils} for automatically participating in 047 * thread-bound transactions, for example managed by {@link CciLocalTransactionManager}. 048 * {@code getConnection} calls and {@code close} calls on returned Connections 049 * will behave properly within a transaction, i.e. always operate on the transactional 050 * Connection. If not within a transaction, normal ConnectionFactory behavior applies. 051 * 052 * <p>This proxy allows data access code to work with the plain JCA CCI API and still 053 * participate in Spring-managed transactions, similar to CCI code in a Java EE/JTA 054 * environment. However, if possible, use Spring's ConnectionFactoryUtils, CciTemplate or 055 * CCI operation objects to get transaction participation even without a proxy for 056 * the target ConnectionFactory, avoiding the need to define such a proxy in the first place. 057 * 058 * <p><b>NOTE:</b> This ConnectionFactory proxy needs to return wrapped Connections 059 * in order to handle close calls properly. Therefore, the returned Connections cannot 060 * be cast to a native CCI Connection type or to a connection pool implementation type. 061 * 062 * @author Juergen Hoeller 063 * @since 1.2 064 * @see javax.resource.cci.ConnectionFactory#getConnection 065 * @see javax.resource.cci.Connection#close 066 * @see ConnectionFactoryUtils#doGetConnection 067 * @see ConnectionFactoryUtils#doReleaseConnection 068 */ 069@SuppressWarnings("serial") 070public class TransactionAwareConnectionFactoryProxy extends DelegatingConnectionFactory { 071 072 /** 073 * Create a new TransactionAwareConnectionFactoryProxy. 074 * @see #setTargetConnectionFactory 075 */ 076 public TransactionAwareConnectionFactoryProxy() { 077 } 078 079 /** 080 * Create a new TransactionAwareConnectionFactoryProxy. 081 * @param targetConnectionFactory the target ConnectionFactory 082 */ 083 public TransactionAwareConnectionFactoryProxy(ConnectionFactory targetConnectionFactory) { 084 setTargetConnectionFactory(targetConnectionFactory); 085 afterPropertiesSet(); 086 } 087 088 089 /** 090 * Delegate to ConnectionFactoryUtils for automatically participating in Spring-managed 091 * transactions. Throws the original ResourceException, if any. 092 * @return a transactional Connection if any, a new one else 093 * @see org.springframework.jca.cci.connection.ConnectionFactoryUtils#doGetConnection 094 */ 095 @Override 096 public Connection getConnection() throws ResourceException { 097 ConnectionFactory targetConnectionFactory = obtainTargetConnectionFactory(); 098 Connection con = ConnectionFactoryUtils.doGetConnection(targetConnectionFactory); 099 return getTransactionAwareConnectionProxy(con, targetConnectionFactory); 100 } 101 102 /** 103 * Wrap the given Connection with a proxy that delegates every method call to it 104 * but delegates {@code close} calls to ConnectionFactoryUtils. 105 * @param target the original Connection to wrap 106 * @param cf the ConnectionFactory that the Connection came from 107 * @return the wrapped Connection 108 * @see javax.resource.cci.Connection#close() 109 * @see ConnectionFactoryUtils#doReleaseConnection 110 */ 111 protected Connection getTransactionAwareConnectionProxy(Connection target, ConnectionFactory cf) { 112 return (Connection) Proxy.newProxyInstance( 113 Connection.class.getClassLoader(), 114 new Class<?>[] {Connection.class}, 115 new TransactionAwareInvocationHandler(target, cf)); 116 } 117 118 119 /** 120 * Invocation handler that delegates close calls on CCI Connections 121 * to ConnectionFactoryUtils for being aware of thread-bound transactions. 122 */ 123 private static class TransactionAwareInvocationHandler implements InvocationHandler { 124 125 private final Connection target; 126 127 private final ConnectionFactory connectionFactory; 128 129 public TransactionAwareInvocationHandler(Connection target, ConnectionFactory cf) { 130 this.target = target; 131 this.connectionFactory = cf; 132 } 133 134 @Override 135 @Nullable 136 public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { 137 // Invocation on Connection interface coming in... 138 139 if (method.getName().equals("equals")) { 140 // Only consider equal when proxies are identical. 141 return (proxy == args[0]); 142 } 143 else if (method.getName().equals("hashCode")) { 144 // Use hashCode of Connection proxy. 145 return System.identityHashCode(proxy); 146 } 147 else if (method.getName().equals("getLocalTransaction")) { 148 if (ConnectionFactoryUtils.isConnectionTransactional(this.target, this.connectionFactory)) { 149 throw new javax.resource.spi.IllegalStateException( 150 "Local transaction handling not allowed within a managed transaction"); 151 } 152 } 153 else if (method.getName().equals("close")) { 154 // Handle close method: only close if not within a transaction. 155 ConnectionFactoryUtils.doReleaseConnection(this.target, this.connectionFactory); 156 return null; 157 } 158 159 // Invoke method on target Connection. 160 try { 161 return method.invoke(this.target, args); 162 } 163 catch (InvocationTargetException ex) { 164 throw ex.getTargetException(); 165 } 166 } 167 } 168 169}