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.ejb.access; 018 019import javax.naming.NamingException; 020 021import org.springframework.aop.framework.ProxyFactory; 022import org.springframework.beans.factory.BeanClassLoaderAware; 023import org.springframework.beans.factory.FactoryBean; 024import org.springframework.lang.Nullable; 025import org.springframework.util.ClassUtils; 026 027/** 028 * Convenient {@link FactoryBean} for remote SLSB proxies. 029 * Designed for EJB 2.x, but works for EJB 3 Session Beans as well. 030 * 031 * <p>See {@link org.springframework.jndi.JndiObjectLocator} for info on 032 * how to specify the JNDI location of the target EJB. 033 * 034 * <p>If you want control over interceptor chaining, use an AOP ProxyFactoryBean 035 * with SimpleRemoteSlsbInvokerInterceptor rather than rely on this class. 036 * 037 * <p>In a bean container, this class is normally best used as a singleton. However, 038 * if that bean container pre-instantiates singletons (as do the XML ApplicationContext 039 * variants) you may have a problem if the bean container is loaded before the EJB 040 * container loads the target EJB. That is because by default the JNDI lookup will be 041 * performed in the init method of this class and cached, but the EJB will not have been 042 * bound at the target location yet. The best solution is to set the lookupHomeOnStartup 043 * property to false, in which case the home will be fetched on first access to the EJB. 044 * (This flag is only true by default for backwards compatibility reasons). 045 * 046 * <p>This proxy factory is typically used with an RMI business interface, which serves 047 * as super-interface of the EJB component interface. Alternatively, this factory 048 * can also proxy a remote SLSB with a matching non-RMI business interface, i.e. an 049 * interface that mirrors the EJB business methods but does not declare RemoteExceptions. 050 * In the latter case, RemoteExceptions thrown by the EJB stub will automatically get 051 * converted to Spring's unchecked RemoteAccessException. 052 * 053 * @author Rod Johnson 054 * @author Colin Sampaleanu 055 * @author Juergen Hoeller 056 * @since 09.05.2003 057 * @see org.springframework.remoting.RemoteAccessException 058 * @see AbstractSlsbInvokerInterceptor#setLookupHomeOnStartup 059 * @see AbstractSlsbInvokerInterceptor#setCacheHome 060 * @see AbstractRemoteSlsbInvokerInterceptor#setRefreshHomeOnConnectFailure 061 */ 062public class SimpleRemoteStatelessSessionProxyFactoryBean extends SimpleRemoteSlsbInvokerInterceptor 063 implements FactoryBean<Object>, BeanClassLoaderAware { 064 065 /** The business interface of the EJB we're proxying. */ 066 @Nullable 067 private Class<?> businessInterface; 068 069 @Nullable 070 private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader(); 071 072 /** EJBObject. */ 073 @Nullable 074 private Object proxy; 075 076 077 /** 078 * Set the business interface of the EJB we're proxying. 079 * This will normally be a super-interface of the EJB remote component interface. 080 * Using a business methods interface is a best practice when implementing EJBs. 081 * <p>You can also specify a matching non-RMI business interface, i.e. an interface 082 * that mirrors the EJB business methods but does not declare RemoteExceptions. 083 * In this case, RemoteExceptions thrown by the EJB stub will automatically get 084 * converted to Spring's generic RemoteAccessException. 085 * @param businessInterface the business interface of the EJB 086 */ 087 public void setBusinessInterface(@Nullable Class<?> businessInterface) { 088 this.businessInterface = businessInterface; 089 } 090 091 /** 092 * Return the business interface of the EJB we're proxying. 093 */ 094 @Nullable 095 public Class<?> getBusinessInterface() { 096 return this.businessInterface; 097 } 098 099 @Override 100 public void setBeanClassLoader(ClassLoader classLoader) { 101 this.beanClassLoader = classLoader; 102 } 103 104 @Override 105 public void afterPropertiesSet() throws NamingException { 106 super.afterPropertiesSet(); 107 if (this.businessInterface == null) { 108 throw new IllegalArgumentException("businessInterface is required"); 109 } 110 this.proxy = new ProxyFactory(this.businessInterface, this).getProxy(this.beanClassLoader); 111 } 112 113 114 @Override 115 @Nullable 116 public Object getObject() { 117 return this.proxy; 118 } 119 120 @Override 121 public Class<?> getObjectType() { 122 return this.businessInterface; 123 } 124 125 @Override 126 public boolean isSingleton() { 127 return true; 128 } 129 130}