Hi, everyone. Thanks in advance for your time and help. I am new using Hibernate. I am using JDK 1.4.2 and Tomcat 4.1.27. I've got the following error :

org.apache.jasper.JasperException: No persister for: java.lang.String
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:254)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2416)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:601)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
at java.lang.Thread.run(Thread.java:534)

root cause

javax.servlet.ServletException: No persister for: java.lang.String
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:536)
at org.apache.jsp.eg_jsp._jspService(eg_jsp.java:96)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:210)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2416)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:601)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
at java.lang.Thread.run(Thread.java:534)

-------------------------------------------------------------------------------------
This is jsp file

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="eg.*" %>
<%@ page import="java.util.*" %>
<%@ page import="net.sf.hibernate.*" %>
<%@ page import="net.sf.hibernate.SessionFactory" %>
<%@ page import="net.sf.hibernate.Session" %>
<%@ page import="net.sf.hibernate.Transaction" %>
<%@ page import="net.sf.hibernate.cfg.Configuration" %>
<%@ page import="net.sf.hibernate.mapping.PersistentClass" %>
<%@ page import="net.sf.hibernate.mapping.Table" %>

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=big5">
</head>
<body>
<%

SessionFactory sessionFactory =
new Configuration().configure().buildSessionFactory();

Session s = sessionFactory.openSession();
Transaction transaction = s.beginTransaction();

Parent p = new Parent();
p.setChild(new ArrayList());
s.save(p);
s.flush();

Child c1 = new Child();
c1.setName("1");
c1.setParentId(p.getId());
p.getChild().add(c1);
s.update(p);
transaction.commit();

s.close();
%>
</body>
</html>

-------------------------------------------------------------------------------------
And this is the xml file:

<hibernate-mapping>

<class name="eg.Parent" table="parent">
<id name="id" type="string" unsaved-value="null" >
<column name="id" sql-type="char(32)" not-null="true"/>
<generator class="uuid.hex"/>
</id>
<bag name="child" inverse="true" lazy="true" cascade="all">
<key column="parent_id"/>
<one-to-many class="eg.Child"/>
</bag>
</class>

<class name="eg.Child" table="child" dynamic-update="true">
<id name="id" type="string" unsaved-value="null" >
<column name="id" sql-type="char(32)" not-null="true"/>
<generator class="uuid.hex"/>
</id>
<property name="name"/>
<many-to-one name="parentId" class="eg.Parent" column="parentId" not-null="true"/>
</class>

</hibernate-mapping>

-------------------------------------------------------------------------------------
this is the sql in case you need:

use govite;
drop table if exists parent;
create table parent (
id varchar(32) not null primary key
);
drop table if exists child;
create table child (
id varchar(32) not null primary key,
name varchar(255),
parentId varchar(32) not null
);

alter table child add constraint pcfk0 foreign key (parentId) references parent (id);

-------------------------------------------------------------------------------------


Does anyone know why I have this error?
If I do not set the parent id of child, the parent id of child would become null. And it would say org.apache.jasper.JasperException: Could not synchronize database state with session: General error, message from server: "Column 'parentId' cannot be null"

How can I solve this problem? Thank you.

Crymore

I'm not sure this is your pb, but your code seems not correct.


should be


The parentId attribute of Child must be of type Parent, not String.

So I strongly advise you to rename child.setParentId to child.setParent.

Hibernate is an O/R mapping, so in java manipulate objects instead of PK ;-)