failed to lazily initialize a collection of role: mall.entit
hi
I have two entity Beans
@Entity
@Table(name = "items")
public class Item implements Serializable {
...
@ManyToOne
@JoinColumn(name = "CATEGORY_ID")
public Category getCategory() {
return category;
}
public void setCategory(Category category) {
this.category = category;
}
}
-------------------------
@Entity
@Table(name = "categories")
public class Category implements Serializable {
private Collection items;
...
@OneToMany(mappedBy="category",cascade=CascadeType.ALL)
public Collection getItems() {
return items;
}
public void setItems(Collection items) {
this.items = items;
}
}
-----------------------------------------
in ItemAdminBean.java
@Stateless
public class ItemAdminBean implements ItemAdminInterface {
@PersistenceContext
protected EntityManager em;
...
public Collection getItemsbyCategory(String catName) {
Category category = (Category) em.createQuery("from Category c WHERE c.name LIKE :catName").setParameter("catName",
catName).getSingleResult();
return category.getItems();
}
}
when i call getItemsbyCategory in jsp page i have a problem
<% Collection items = itemAdmin.getItemsbyCategory(request.getParameter("categoryChoice"));
%>
<%for (Iterator iter = items.iterator(); iter.hasNext();) {
Item item = (Item) iter.next();
%>
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: mall.entityDto.Category.items, no session or session was closed
org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:358)
org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:350)
org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:343)
org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:86)
org.hibernate.collection.PersistentBag.iterator(PersistentBag.java:246)
org.apache.jsp.online_005fmall.Products_jsp._jspService(Products_jsp.java:111)
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)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.
can you help me?
