One problem about EJB 3 persistence!

[cnsunyong]

Entironment:Jboss4+Eclipse+MS SQLServer2000+EJB3

servlet:
...
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("start.");
Nationality na = nation.getNa("cn","china");
System.out.println("cd is " + na.getCode());

}

/**
* Initialization of the servlet.
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
try {
Context ctx = new InitialContext();
nation = (Nation)ctx.lookup(Nation.class.getName());
} catch (NamingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
...

SessionBean Remote:

@Remote
public interface Nation {
public void addNation(String cd,String name);
public Nationality getNa(String cd,String name);
}

SessionBean:
public @Stateless class NationBean implements Nation {


public void addNation(String cd, String name) {

System.out.println();


}
public Nationality getNa(String cd,String name) {
Nationality nation = new Nationality();
nation.setCode(cd);
nation.setName(name);
return nation;
}



}

EntityBean:

@Table(name="Nationalities")
@Entity(access=AccessType.FIELD)
public class Nationality {
@Id(generate=GeneratorType.TABLE)
@Column(name="code")
private String code;
@Basic(fetch=FetchType.LAZY)
@Column(nullable=false)
private String name;
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}

}

Exception:

Source not found for $Proxy81.getNa(String, String) line: not available

java.lang.reflect.UndeclaredThrowableException
at $Proxy81.getNa(Unknown Source)
at web.TestSevlet.doPost(TestSevlet.java:63)
at web.TestSevlet.doGet(TestSevlet.java:47)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.jboss.web.tomcat.security.CustomPrincipalValve.invoke(CustomPrincipalValve.java:39)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:159)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:59)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.io.NotSerializableException: test.Nationality
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1075)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at org.jboss.aop.joinpoint.InvocationResponse.writeExternal(InvocationResponse.java:86)
at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1304)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1282)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at java.rmi.MarshalledObject.(MarshalledObject.java:92)
at org.jboss.ejb3.stateless.StatelessContainer.dynamicInvoke(StatelessContainer.java:214)
at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:107)
at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:37)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:98)
at org.jboss.ejb3.stateless.StatelessRemoteProxy.invoke(StatelessRemoteProxy.java:88)
... 24 more

[rexorient]

You're using the Remote interface, which means that the getNa() method result needs to be serialized.

Changing the bean to:

public class Nationality implements Serializable {
...
}

would fix this.