EJB遠程客戶端拋出NullPointerException異常：無法獲取SerialContextProvider

Question

我有一個無狀態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; 
    } 
    } 

我已經當我試圖訪問與@Remote

@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; 
    } 

註釋界面來部署這個在GlassFish它由客戶端即一個Java桌面應用程序： 它是拋出一個NullpointerException

客戶端代碼：

 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(); 

錯誤是： 顯示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） 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） 線程「main」中的異常javax.naming.NamingException：查找失敗在SerialContext中的'java：global/EJBDemo2EAR/EJBDemo2/CalculatorImpl！com.java.stateless.Calculator'[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} [根異常是javax.naming.NamingException：無法獲取SerialContext的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.f actory.state = com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl} [根異常是顯示java.lang.NullPointerException]] 在com.sun.enterprise.naming.impl.SerialContext.lookup

Answer 1

在context.lookup只是通過完全限定接口名稱：

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