[Russ]

I have a simple application using a jsp to present information. It works through Hibernate to a MySQL database. I am using Eclipse 3.1.1, MyEclipse workbench 4.1 MySQL 5.0, and Hibernate 3.0 The application is running on JBoss4.0.3SP1 This error is taking place when I take the results and try to place it in the session.

What I want to know is retreiving the information from the database looks at though I am dealing with objects and not a collection of Catalog.class. When I go look at the current version of Hibernate 3.1, I can see several overloaded methods for createSQLQuery, yet I can not find them when I try to use them in my code. The only method avaialble to me is the one method with a String as a parameter for the SQL query. I would assume this is because of MyEclipse only using Hibernate3.0 and not Hibernate 3.1.

How does one ensure Hibernate returns a collection of Catalog classes in the collection?

In the JSP I am calling: AddJournal.jsp

  List catalogList = CatalogService.getInstance().getCatalogList();
  request.setAttribute("catalog", catalogList); <<< exception is happening here.....

In the Hibernate portion: CatalogService

public List getCatalogList(){
        
        Session session = null;
        try{
             session = SessionFactory.currentSession();
             // use lower case names for attritbutes and 
             // substitute for table name
             String SQL_QUERY ="SELECT c.catalogId,c.journal,c.publisher," + 
             "c.date,c.title,c.author FROM Catalog c";

             Query query = session.createQuery(SQL_QUERY);
             for(Iterator it=query.iterate();it.hasNext();){
               Object[] row = (Object[]) it.next();   
               System.out.println("CatalogId: " + row[0]);
               System.out.println("Journal: " + row[0]);
               System.out.println("Publisher: " + row[1]);
               System.out.println("Date: " + row[2]);
               System.out.println("Title: " + row[3]);
               System.out.println("Author: " + row[4]);
             }//end for loop
             query.setMaxResults(10);
             return query.list();
        }catch (ObjectNotFoundException onfe){
            return null;
        }finally {
            if(session != null){
                try{
                    session.close();
                }catch (HibernateException e){
                    System.err.println("Hibernate Exception: "+ e.getMessage());
                    throw new RuntimeException(e);
                }
            }
        }
    }//end method 

When I run the application, I get this error:

[09:17:33,828] [ERROR] [[jsp]] Servlet.service() for servlet jsp threw exception
java.lang.ClassCastException: [Ljava.lang.Object;
    at org.apache.jsp.AddJournal_jsp._jspService(org.apache.jsp.AddJournal_jsp:150)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    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)

[Haris Peco]

russray,

Your ‘getCatalogList’ return collection of Catalog (try debug or use generics).Your error isn’t related with hibernate.I suppose that you can’t set attribute of request to list.

Best

[Russ]

Take a look at the getCatalogList method.

If I try to change the object from a Object[] to Catalog. I get the same problem–ClassCastException. This is where I make the deduction that the I was not getting a collection of Catalog objects back from Hibernate. Is this not what suppose to happen?

[Haris Peco]

russray,

I will try your problem today, but no immediately.Please, be patient.I answer you

Thanks

[Russ]

Okay, I figured it out.

public List getCatalogList(){
        
        Session session = null;
        try{
             session = SessionFactory.currentSession();
             // use lower case names for attritbutes and 
             // substitute for table name
             String SQL_QUERY ="SELECT c.catalogId,c.journal,c.publisher," + 
             "c.date,c.title,c.author FROM Catalog c";
             List catalogList =  session.createCriteria(Catalog.class, SQL_QUERY).list();
             for(Iterator it=catalogList.iterator();it.hasNext();){
                 Catalog cat = (Catalog) it.next();
                 System.out.println("CatalogId: " + cat.getCatalogId());
                 System.out.println("Journal: " + cat.getJournal());
                 System.out.println("Publisher: " + cat.getPublisher());
                 System.out.println("Date: " + cat.getDate());
                 System.out.println("Title: " + cat.getTitle());
                 System.out.println("Author: " + cat.getAuthor());
               }//end for loop
             
             return catalogList;
        }catch (ObjectNotFoundException onfe){
            return null;
        }finally {
            if(session != null){
                try{
                    session.close();
                }catch (HibernateException e){
                    System.err.println("Hibernate Exception: "+ e.getMessage());
                    throw new RuntimeException(e);
                }
            }
        }
    }//end method 

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