Hi Edward,
            to understand the error you need to know more about the EJB specification. It states that the return types of all remote
methods as well as the parameters to them should be serializable. Therefore create a class which stores a ResultSet object and which
implements the Serializable interface. The return type of your method should be this class rather the ResultSet object. 

Mamata.

-----Original Message-----
From: "Edward"<zhangsc@n...>
To: "Enterprise Java Beans"<enterprise_java_beans@p...>
Date: Sat Jun 01 01:05:35 PDT 2002
Subject: [enterprise_java_beans] where is error in my ejb?

>Hello,
>  I want to get ResultSet by search data from Oracle DB,my steps are follows:first I visit Servlet with IE,then call EJB from
Servlet,at last search data from Oracle through EJB.But I got many errors,
>//Servlet file which named "GetUserIdentity.java"
>
>public class GetUserIdentity extends HttpServlet
>{
>   public void doPost(HttpServletRequest request,HttpServletResponse response) 
>     throws ServletException,IOException
> {
>   try
>  {
>   Properties prop=new Properties();  
>   prop.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");
>   prop.put(Context.PROVIDER_URL,"t3://192.168.39.152:7001");
>   Context ctx=new InitialContext(prop);
>   Object objref=ctx.lookup("CheckPassword");
>   CheckPasswordHome home=(CheckPasswordHome)javax.rmi.PortableRemoteObject.narrow(
>      objref,CheckPasswordHome.class);
>   CheckPassword ss=home.create();
>   ResultSet message;
>   message=ss.TableInfo();
>   ...
>   }
>   catch(Exception e)
>  {
>   e.printStackTrace();
>  }
>  }
>}
>
>//EJB file which named "CheckPassword.java"
>package loginEJB;
>import java.rmi.RemoteException;
>import java.sql.ResultSet;
>import java.util.Enumeration;
>import java.util.Properties;
>
>public interface CheckPassword extends javax.ejb.EJBObject
>{
> ResultSet TableInfo() throws java.rmi.RemoteException;
>}
>
>//The file "CheckPasswordEJB.java"
>
>import java.sql.Statement;
>import java.sql.ResultSet;
>import java.util.Enumeration;
>import java.util.Properties;
>public class CheckPasswordEJB implements javax.ejb.SessionBean
>{
> public void ejbCreate()
> {
>  System.out.println("ejbCreate() called");
> }
> ...
>  public ResultSet TableInfo() throws java.rmi.RemoteException
> {
>  String driverClass="oracle.jdbc.driver.OracleDriver";
>  String url="jdbc:oracle:thin:@as_server:1526:db817";
>  Connection connection;
>  try
>  {
>   // Oracle Client - Server Thin Driver
>   Class.forName(driverClass);
>  }
>  catch(ClassNotFoundException e)
>  {
>   e.printStackTrace();
>  }
>  try
>  {
>   connection=DriverManager.getConnection(url,"eino","eino");
>   Statement stmt=connection.createStatement();
>   stmt.executeQuery("select * from table_info_tbl");
>   ResultSet rs=stmt.getResultSet();
>   return rs;
>  }
>  catch(SQLException e)
>  {
>   e.printStackTrace();
>   return null;
>  }
> }
>}
>
>When I visit EJB,I got errors:
>Starting service Tomcat-Standalone
>Apache Tomcat/4.0.1
>Starting service Tomcat-Apache
>Apache Tomcat/4.0.1
>java.rmi.MarshalException: error marshalling return; nested exception is:
>        java.io.NotSerializableException: oracle.jdbc.driver.OracleResultSetImpl
>
>
>Start server side stack trace:
>java.rmi.MarshalException: error marshalling return; nested exception is:
>        java.io.NotSerializableException: oracle.jdbc.driver.OracleResultSetImpl
>
>java.io.NotSerializableException: oracle.jdbc.driver.OracleResultSetImpl
>        at java.io.ObjectOutputStream.outputObject(ObjectOutputStream.java:1148)
>
>        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:366)
>        at weblogic.common.internal.ChunkedObjectOutputStream.writeObject(Chunke
>dObjectOutputStream.java:102)
>        at weblogic.common.internal.ChunkedObjectOutputStream.writeObject(Chunke
>dObjectOutputStream.java:108)
>        at loginEJB.CheckPasswordEJB_28r6w3_EOImpl_WLSkel.invoke(Unknown Source)
>
>        at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:296)
>        at weblogic.rmi.cluster.ReplicaAwareServerRef.invoke(ReplicaAwareServerR
>ef.java:93)
>        at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.jav
>a:265)
>        at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest
>.java:22)
>        at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
>        at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
>End  server side stack trace
>; nested exception is:
>        java.io.NotSerializableException: oracle.jdbc.driver.OracleResultSetImpl
>
>
>Start server side stack trace:
>java.io.NotSerializableException: oracle.jdbc.driver.OracleResultSetImpl
>        at java.io.ObjectOutputStream.outputObject(ObjectOutputStream.java:1148)
>
>        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:366)
>        at weblogic.common.internal.ChunkedObjectOutputStream.writeObject(Chunke
>dObjectOutputStream.java:102)
>        at weblogic.common.internal.ChunkedObjectOutputStream.writeObject(Chunke
>dObjectOutputStream.java:108)
>        at loginEJB.CheckPasswordEJB_28r6w3_EOImpl_WLSkel.invoke(Unknown Source)
>
>        at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:296)
>        at weblogic.rmi.cluster.ReplicaAwareServerRef.invoke(ReplicaAwareServerR
>ef.java:93)
>        at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.jav
>a:265)
>        at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest
>.java:22)
>        at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
>        at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
>End  server side stack trace
>
>java.io.NotSerializableException: oracle.jdbc.driver.OracleResultSetImpl
>
>Start server side stack trace:
>java.io.NotSerializableException: oracle.jdbc.driver.OracleResultSetImpl
>        at java.io.ObjectOutputStream.outputObject(ObjectOutputStream.java:1148)
>
>        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:366)
>        at weblogic.common.internal.ChunkedObjectOutputStream.writeObject(Chunke
>dObjectOutputStream.java:102)
>        at weblogic.common.internal.ChunkedObjectOutputStream.writeObject(Chunke
>dObjectOutputStream.java:108)
>        at loginEJB.CheckPasswordEJB_28r6w3_EOImpl_WLSkel.invoke(Unknown Source)
>
>        at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:296)
>        at weblogic.rmi.cluster.ReplicaAwareServerRef.invoke(ReplicaAwareServerR
>ef.java:93)
>        at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.jav
>a:265)
>        at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest
>.java:22)
>        at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
>        at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
>End  server side stack trace
>
>        <<no stack trace available>>
>
>I don't know why my program is error.
>Any idea will be appreciated! How to correct ?
>Edward
>


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