EJB 远程客户端抛出空指针异常：无法获取 SerialContextProvider

Question

我有一个无状态的 bean

 @Stateless
 public class CalculatorImpl implements Calculator {
 private static final long serialVersionUID = 1L;
 @Override
  public int add(int a, int b) {
return a+b;
  }
    @Override
   public int sub(int a, int b) {
return a-b;
   }
   @Override
   public int mul(int a, int b) {
return a*b;
  }
   @Override
    public float div(int a, int b) {
return a/b;
   }
    }

我已经在 glassfish 上部署了这个，界面用@Remote 注释

  @Remote
  public interface Calculator extends Serializable{
  public int add(int a, int b)throws RemoteException;
  public int sub(int a, int b)throws RemoteException;
   public int mul(int a, int b)throws RemoteException;
   public float div(int a, int b)throws RemoteException;
  }

当我尝试通过客户端（即 java 桌面应用程序）访问它时： 它正在抛出 NullpointerException

客户端代码：

      MyClient client= new MyClient();
  Properties props = new Properties();
  props.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.enterprise.naming.SerialInitContextFactory");
  props.setProperty("org.omg.CORBA.ORBInitialHost", "localhost");

  // glassfish default port value will be 3700, 
  // but im using tcpviewer to redirect my 50005 port to 3700
  props.setProperty("org.omg.CORBA.ORBInitialPort", "3700");

  InitialContext context = new InitialContext(props);

 client.cart = (ShoppingCart) context
        .lookup("java:global/EJBDemo2EAR/EJBDemo2/CalculatorImpl!com.java.stateless.Calculator");
System.out.println("In doget");
client.cart.buy("soap", 12);
client.cart.getCartContents();

错误是： java.lang.NullPointerException 在 com.sun.enterprise.naming.impl.SerialContext.getORB(SerialContext.java:347) 在 com.sun.enterprise.naming.impl.SerialContext.getProviderCacheKey(SerialContext.java:354) 在 com.sun.enterprise.naming.impl.SerialContext.getRemoteProvider(SerialContext.java:384) 在 com.sun.enterprise.naming.impl.SerialContext.getProvider(SerialContext.java:329) 在 com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:477) 在 com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:438) 在 javax.naming.InitialContext.lookup(InitialContext.java:417) 在 com.java.client.MyClient.main(MyClient.java:30) 线程“主”javax.naming.NamingException 中的异常：在 SerialContext [myEnv={org.omg.CORBA.ORBInitialPort=3700, java.naming.factory.initial=com.sun.enterprise.naming.SerialInitContextFactory，org.omg.CORBA.ORBInitialHost=localhost，java.naming.factory.url.pkgs=com.sun.enterprise.naming，java.naming。 factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl} [根异常是 javax.naming.NamingException：无法为 SerialContext 获取 SerialContextProvider[myEnv={org.omg.CORBA.ORBInitialPort=3700， java.naming.factory.initial=com.sun.enterprise.naming.SerialInitContextFactory，org.omg.CORBA.ORBInitialHost=localhost，java.naming.factory.url.pkgs=com.sun.enterprise.naming，java.naming。 factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl} [根异常是 java.lang.NullPointerException]] 在 com.sun.enterprise.naming.impl.SerialContext.lookup

Answer 1

在 context.lookup 中只需传递完全限定的接口名称：

client.cart=(ShoppingCart)context.lookup("com.java.stateless.Calculator");