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 local Stateless Session Bean (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 LocalSlsbInvokerInterceptor 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 * @author Rod Johnson 047 * @author Colin Sampaleanu 048 * @since 09.05.2003 049 * @see AbstractSlsbInvokerInterceptor#setLookupHomeOnStartup 050 * @see AbstractSlsbInvokerInterceptor#setCacheHome 051 */ 052public class LocalStatelessSessionProxyFactoryBean extends LocalSlsbInvokerInterceptor 053 implements FactoryBean<Object>, BeanClassLoaderAware { 054 055 /** The business interface of the EJB we're proxying. */ 056 @Nullable 057 private Class<?> businessInterface; 058 059 @Nullable 060 private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader(); 061 062 /** EJBLocalObject. */ 063 @Nullable 064 private Object proxy; 065 066 067 /** 068 * Set the business interface of the EJB we're proxying. 069 * This will normally be a super-interface of the EJB local component interface. 070 * Using a business methods interface is a best practice when implementing EJBs. 071 * @param businessInterface set the business interface of the EJB 072 */ 073 public void setBusinessInterface(@Nullable Class<?> businessInterface) { 074 this.businessInterface = businessInterface; 075 } 076 077 /** 078 * Return the business interface of the EJB we're proxying. 079 */ 080 @Nullable 081 public Class<?> getBusinessInterface() { 082 return this.businessInterface; 083 } 084 085 @Override 086 public void setBeanClassLoader(ClassLoader classLoader) { 087 this.beanClassLoader = classLoader; 088 } 089 090 @Override 091 public void afterPropertiesSet() throws NamingException { 092 super.afterPropertiesSet(); 093 if (this.businessInterface == null) { 094 throw new IllegalArgumentException("businessInterface is required"); 095 } 096 this.proxy = new ProxyFactory(this.businessInterface, this).getProxy(this.beanClassLoader); 097 } 098 099 100 @Override 101 @Nullable 102 public Object getObject() { 103 return this.proxy; 104 } 105 106 @Override 107 public Class<?> getObjectType() { 108 return this.businessInterface; 109 } 110 111 @Override 112 public boolean isSingleton() { 113 return true; 114 } 115 116}