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

Question

我有一个无状态的豆子

@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;
}
}

我已经将其部署在带有@Remote注释的 glassfish 上

@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： 它抛出一个空指针异常

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 at com.sun.enterprise.naming.impl.SerialContext.getORB(SerialContext.java：347) at com.sun.enterprise.naming.impl.SerialContext.getProviderCacheKey(SerialContext.java：354) at com.sun.enterprise.naming.impl.SerialContext.getRemoteProvider(SerialContext.java：384) at com.sun.enterprise.naming.impl.SerialContext.getProvider(SerialContext.java：329) at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java：477) at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java：438)at javax.naming.InitialContext.lookup(InitialContext.java：417) at com.java.client.MyClient.main(MyClient.java：30)线程 "main" 中的异常 javax.naming.NamingException： Lookup for 'java：global/EJBDemo2EAR/EJBDemo2/CalculatorImpl！com.java.stateless.Calculator' in 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} [Root exception is javax.naming.NamingException： T無法獲得 SerialContextProvider for 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} [Root exception is java.lang.NullPointerException]]at 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");