【发布时间】：2011-10-12 14:51:27
【问题描述】：
我正在尝试编写一个简单的无状态会话 bean，但我在查找时给出的狭窄参考存在问题。 我得到了
类转换异常
我用
Eclipse IDE
我的豆类
package codes;
import java.rmi.RemoteException;
import javax.ejb.EJBException;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
public class SinaBean implements SessionBean {
/**
*
*/
private static final long serialVersionUID = 1L;
public String getHello()
{
return "hello";
}
public void ejbCreate(){
}
@Override
public void ejbActivate() throws EJBException, RemoteException {
// TODO Auto-generated method stub
}
@Override
public void ejbPassivate() throws EJBException, RemoteException {
// TODO Auto-generated method stub
}
@Override
public void ejbRemove() throws EJBException, RemoteException {
// TODO Auto-generated method stub
}
@Override
public void setSessionContext(SessionContext arg0) throws EJBException,
RemoteException {
// TODO Auto-generated method stub
}
}
我的主界面
package codes;
import java.rmi.RemoteException;
import javax.ejb.CreateException;
import javax.ejb.EJBHome;
public interface SinaHome extends EJBHome {
public SinaObject create() throws RemoteException,CreateException;
}
我的组件
package codes;
import java.rmi.RemoteException;
import javax.ejb.EJBObject;
public interface SinaObject extends EJBObject {
String getHello() throws RemoteException;
}
我的客户
package codes;
import java.util.Properties;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.rmi.PortableRemoteObject;
public class Client {
/**
* @param args
*/
public static void main(String[] args) {
Context con=null;
try {
Properties p=new Properties();
p.setProperty(Context.INITIAL_CONTEXT_FACTORY,
"org.jnp.interfaces.NamingContextFactory");
p.setProperty(Context.PROVIDER_URL, "localhost:1099");
p.setProperty(Context.URL_PKG_PREFIXES,
"org.jboss.namingrg.jnp.interfaces");
con = new InitialContext(p);
Object o=con.lookup("SinaBean");
System.out.println(o);/***/untill know it works.it sysout :
//org.jnp.interfaces.NamingContext@e83912***
@SuppressWarnings("unused")
SinaHome sh=(SinaHome)PortableRemoteObject.narrow(o, SinaHome.class);//***exeption is here!!***
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
我的 xml 文件
<?xml version="1.0" encoding="UTF-8"?>
<ejb-jar version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/ejb-jar_3_0.xsd">
<display-name>Ejb </display-name>
<enterprise-beans>
<session>
<display-name>SinaBean</display-name>
<ejb-name>SinaBean</ejb-name>
<home>codes.SinaHome</home>
<remote>codes.SinaObject</remote>
<ejb-class>codes.SinaBean</ejb-class>
<session-type>Stateless</session-type>
<transaction-type>Bean</transaction-type>
<security-identity>
<description></description>
<use-caller-identity></use-caller-identity>
</security-identity>
</session>
</enterprise-beans>
</ejb-jar>
我收到的异常
java.lang.ClassCastException
at com.sun.corba.se.impl.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:229)
at javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:137)
at codes.Client.main(Client.java:27)
Caused by: java.lang.ClassCastException: org.jnp.interfaces.NamingContext cannot be cast to org.omg.CORBA.Object
at com.sun.corba.se.impl.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:212)
... 2 more
我将非常感谢您的建议。
【问题讨论】：
标签： java eclipse ejb jndi narrowing