基于Spring的RPC通讯模型的使用与比较

/**
   * 服务端：
   * <p>
   * 1、默认情况下，RmiServiceExporter 会尝试绑定到本地机器1099端口上的RMI注册表。
   * 2、如果在这个端口没有发现RMI注册表，RmiServiceExporter 将会启动一个注册表。
   * 3、可重写注册表的路径和端口，这个是个大坑，当你设置了registryHost属性的时候，源码中就不创建Registry，而是直接去获取，可是我们自己也没有创建，所以就会报连接不上。
   *
   * @param userService
   * @return
   */
  @Bean(name = "rmiServiceExporter")
  public RmiExporter rmiServiceExporter(UserService userService, Environment environment) {
    String registryHost = environment.getProperty("registryHost");
    int registryPort = environment.getProperty("registryPort", Integer.class);
    RmiExporter rmiExporter = new RmiExporter();
    rmiExporter.setService(userService); //要把该bean(即rmiServiceImpl)发布为一个RMI服务
    rmiExporter.setServiceName("RmiService"); //命名RMI 服务
    rmiExporter.setServiceInterface(UserService.class); //指定服务所实现的接口
    rmiExporter.setRegistryHost(registryHost);
    rmiExporter.setRegistryPort(registryPort);
    return rmiExporter;
  }

/**
 * Created by XiuYin.Cui on 2018/5/14.
 * 
 * 解决设置 registryHost 后，报连接拒绝的问题。
 */
public class RmiExporter extends RmiServiceExporter {

  @Override
  protected Registry getRegistry(String registryHost, int registryPort, RMIClientSocketFactory clientSocketFactory,
                  RMIServerSocketFactory serverSocketFactory) throws RemoteException {


    if (registryHost != null) {
      try {
        if (logger.isInfoEnabled()) {
          logger.info("Looking for RMI registry at port '" + registryPort + "' of host [" + registryHost + "]");
        }
        //把spring源代码中这里try起来，报异常就创建一个
        Registry reg = LocateRegistry.getRegistry(registryHost, registryPort, clientSocketFactory);
        testRegistry(reg);
        return reg;
      } catch (RemoteException ex) {
        LocateRegistry.createRegistry(registryPort);
        Registry reg = LocateRegistry.getRegistry(registryHost, registryPort, clientSocketFactory);
        testRegistry(reg);
        return reg;
      }
    } else {
      return getRegistry(registryPort, clientSocketFactory, serverSocketFactory);
    }
  }
}

@Bean(name = "rmiUserServiceClient")
  public RmiProxyFactoryBean RmiUserServiceClient(){
    RmiProxyFactoryBean rmiProxyFactoryBean = new RmiProxyFactoryBean();
    rmiProxyFactoryBean.setServiceUrl("rmi://127.0.0.1:9999/RmiService");
    rmiProxyFactoryBean.setServiceInterface(UserService.class);
    rmiProxyFactoryBean.setLookupStubOnStartup(false);//不在容器启动后创建与Server端的连接
    rmiProxyFactoryBean.setRefreshStubOnConnectFailure(true);//连接出错的时候自动重连
    rmiProxyFactoryBean.afterPropertiesSet();
    return rmiProxyFactoryBean;
  }

 @Resource(name="rmiUserServiceClient")
  private UserService userService;

/**
   * hessian没有注册表，不需要设置 serviceName
   */
  @Bean(name = "hessianServiceExporter")
  public HessianServiceExporter hessianServiceExporter(UserService userService) {
    HessianServiceExporter hessianServiceExporter = new HessianServiceExporter();
    hessianServiceExporter.setService(userService);
    hessianServiceExporter.setServiceInterface(UserService.class);
    return hessianServiceExporter;
  }
  /**
   * 需要配置一个URL映射来确保DispatcherServlet把请求转给HessianServiceExporter
   */
  @Bean(name = "handlerMapping")
  public HandlerMapping handlerMapping() {
    SimpleUrlHandlerMapping handlerMapping = new SimpleUrlHandlerMapping();
    Properties mappings = new Properties();
    mappings.setProperty("/user.service", "hessianServiceExporter");
    handlerMapping.setMappings(mappings);
    return handlerMapping;
  }

@Bean(name = "hessianUserServiceClient")
  public HessianProxyFactoryBean hessianUserServiceClient(){
    HessianProxyFactoryBean proxy = new HessianProxyFactoryBean();
    proxy.setServiceUrl("http://127.0.0.1:8080/user.service");
    proxy.setServiceInterface(UserService.class);
    return proxy;
  }

  @Resource(name="hessianUserServiceClient")
  private UserService userService; 

/*Http Invoker*/
  @Bean(name = "httpInvokerServiceExporter")
  public HttpInvokerServiceExporter httpInvokerServiceExporter(UserService userService){
    HttpInvokerServiceExporter httpInvokerServiceExporter = new HttpInvokerServiceExporter();
    httpInvokerServiceExporter.setService(userService);
    httpInvokerServiceExporter.setServiceInterface(UserService.class);
    return httpInvokerServiceExporter;
  }
  /**
   * 需要配置一个URL映射来确保DispatcherServlet把请求转给HessianServiceExporter
   */
  @Bean(name = "handlerMapping")
  public HandlerMapping handlerMapping() {
    SimpleUrlHandlerMapping handlerMapping = new SimpleUrlHandlerMapping();
    Properties mappings = new Properties();
    mappings.setProperty("/user.service", "hessianServiceExporter");
    mappings.setProperty("/userInvoker.service", "httpInvokerServiceExporter");
    handlerMapping.setMappings(mappings);
    return handlerMapping;
  }

@Bean(name = "httpInvokerUserServiceClient")
  public HttpInvokerProxyFactoryBean httpInvokerUserServiceClient(){
    HttpInvokerProxyFactoryBean proxy = new HttpInvokerProxyFactoryBean();
    proxy.setServiceUrl("http://127.0.0.1:8080//userInvoker.service");
    proxy.setServiceInterface(UserService.class);
    return proxy;
  }