Display data via EJB 3

[weiming]

Hi there

I can create, insert and delete date via EJB 3, but I got a problem with displaying data.

I created an entitybean "UserCredentialsEntity.java", which defined all setter/getter.

In interface "UserCredentialsHandler.java", I set a method
"public Collection getUser(String firstName);"

In Javabean "UserCredentialsBean.java", I implemented this method
"public Collection getUser(String firstName){
String oql = "select u from UserCredentialsEntity u where u.firstName=:firstName";

return em.createQuery(oql).setParameter("firstName", firstName).getResultList();
}"

Then I create a test.jsp to test this method: (code about displaying data)

<%@page import="javax.naming.*,
java.text.*,
java.util.*,
com.SurveyMaker.ejb.entity.*,
com.SurveyMaker.ejb.session.*"%>

<%!
private UserCredentialsHandler aUser = null;

public void jspInit () {
try {
InitialContext ctx = new InitialContext();
aUser = (UserCredentialsHandler) ctx.lookup("surveymaker/UserCredentialsBean/local");
} catch (Exception e) {
e.printStackTrace ();
}
}%>

<%
Collection somePeople= aUser.getUser("Allen");
for(Iterator iter = somePeople.iterator(); iter.hasNext();){
UserCredentialsEntity user = (UserCredentialsEntity)iter.next();
%>
Username: <%=user.getFirstName() %>
<%
}
%>

It brings me an error:

org.apache.jasper.JasperException: Exception in JSP: /test.jsp:29

26: <%
27: Collection somePeople= aUser.getUser("Allen");
28: for(Iterator iter = somePeople.iterator(); iter.hasNext();){
29: UserCredentialsEntity user = (UserCredentialsEntity)iter.next();
30: %>
31: Username: <%=user.getFirstName() %>
32: <%


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:504)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

root cause

java.lang.ClassCastException: com.SurveyMaker.ejb.entity.UserCredentialsEntity
org.apache.jsp.test_jsp._jspService(test_jsp.java:71)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

Can anyone help me, please?

Cheers
Ming