public class RmiServiceExporter extends RmiBasedExporter  implements InitializingBean, DisposableBean 

public void afterPropertiesSet() throws RemoteException{  prepare();
}
public void prepare() throws RemoteException{  //检查验证service
        checkService();  if(serviceName == null)  throw new IllegalArgumentException("Property 'serviceName' is required");  //如果用户在配置文件中配置了clientSocketFactory或者serverSocketFactory的处理  //如果配置中的clientSocketFactory同时又实现了RMIServerSocketFactory接口那么会忽略配置 //中的serverSocketFactory而使用clientSocketFactory代替 if(clientSocketFactory instanceof RMIServerSocketFactory)  serverSocketFactory = (RMIServerSocketFactory)clientSocketFactory;  //clientSocketFactory和serverSocketFactory要么同时出现，要么都不出现  if(clientSocketFactory != null && serverSocketFactory == null || clientSocketFactory == null && serverSocketFactory != null)  throw new IllegalArgumentException("Both RMIClientSocketFactory and RMIServerSocketFactory or none required");  //如果配置中的registryClientSocketFactory同时实现了RMIServerSocketFactory接口那么会忽略配置张的  //registryServerSocketFactory而使用registryClientSocketFactory代替  if(registryClientSocketFactory instanceof RMIServerSocketFactory)  registryServerSocketFactory = (RMIServerSocketFactory)registryClientSocketFactory;  //不允许出现只配置registryServerSocketFactory而不配置registryClientSocketFactory的情况  if(registryClientSocketFactory == null && registryServerSocketFactory != null)  throw new IllegalArgumentException("RMIServerSocketFactory without RMIClientSocketFactory for registry not supported");  createdRegistry = false;  //确定RMI registry  if(registry == null)  {  registry = getRegistry(registryHost, registryPort, registryClientSocketFactory, registryServerSocketFactory);  createdRegistry = true;  }  //初始化以及缓存导出的Object  //此时通常情况下是使用RMIInvocationWrapper封装的JDK代理类，切面为RemoteInvocationTraceInterceptor  exportedObject = getObjectToExport();  if(logger.isInfoEnabled())  logger.info((new StringBuilder()).append("Binding service '").append(serviceName).append("' to RMI registry: ").append(registry).toString());  //Export RMI object  if(clientSocketFactory != null)  //使用给定的套接字工厂指定的传送方式导出远程对象，以便能够接收传入的调用  //clientSocketFactory：进行远程对象调用的客户端套接字工厂  //serverSocketFactory：接收远程调用的服务端套接字工厂
            UnicastRemoteObject.exportObject(exportedObject, servicePort, clientSocketFactory, serverSocketFactory);  else  //导出remote object，以使它能够接收特定端口的调用
            UnicastRemoteObject.exportObject(exportedObject, servicePort);  try  {  //绑定服务名称到remote object,外界调用serviceName的时候会被erportObject接收  if(replaceExistingBinding)  registry.rebind(serviceName, exportedObject);  else  registry.bind(serviceName, exportedObject);  }  catch(AlreadyBoundException ex)  {  unexportObjectSilently();  throw new IllegalStateException((new StringBuilder()).append("Already an RMI object bound for name '").append(serviceName).append("': ").append(ex.toString()).toString());  }  catch(RemoteException ex)  {  unexportObjectSilently();  throw ex;  }  }