How I can find out the cause of the command object ...

[vw729]

I run into this error while bringing up a form:

ERROR org.springframework.web.servlet.tags.BindTag.doSta rtTag:71 - Neither Errors instance nor plain target object for bean name 'command' available as request attribute
javax.servlet.jsp.JspTagException: Neither Errors instance nor plain target object for bean name 'command' available as request attribute

I think the reason is either the command object isn't initiated properly or the object is not saved as a request attribute. For the information I have, I can't see the neither case. The command object class is instanceable and the command is definited in the servlet.xml file as the following:

<property name="commandName"><value>articleForm</value></property>
<property name="commandClass"><value>com.xxx.web.article.New ArticleForm</value></property>

Any idea on how to find out the cause?

Thanks very much for any of your inputs in advance.

v.

[Alef Arendsen]

In the controller, where you're returning the model and view, have you used errors.getModel() as the basis for the model you're returning?

After a form has successfully been submitted the redirects to the success view won't contain the command object anymore (unless you're explicitly adding it to the model, using errors.getModel()).

rgds,
alef

[vw729]

Thanks for your response, Alef.

The command object is not a model object, but a form object which in terms contains a model object. The all methods of the class are below:

public AddArticleFormController() {
// need a session to hold the formBackingObject
setSessionForm(true);
}

protected Map referenceData(HttpServletRequest request)
throws ServletException {
logger.debug(""); // called
Map refData = new HashMap();
refData.put("categories", cManager.getCategories());
return refData;
}

protected Object formBackingObject(HttpServletRequest request)
throws Exception {
logger.debug(""); //called

User user = (WebAppUtils.getUserSession(request)).getUser();
if (user == null)
throw new ServletException("User session unfound");
return new NewArticleForm(...);
}

protected void initBinder(HttpServletRequest request,
ServletRequestDataBinder binder) throws Exception {
logger.debug("");
binder.registerCustomEditor(byte[].class,
new ByteArrayMultipartFileEditor());
}

protected void onBind(HttpServletRequest request, Object command) {
logger.debug(""); // not called???
NewArticleForm entryForm = (NewArticleForm) command;
int typeId = Integer.parseInt(request.getParameter("catId"));
Article a = entryForm.getArticle();
a.setCategory((Category) EntityUtils.getById(cManager
.getCategories(), Category.class, typeId));
}

/** Method inserts a new <code>Entry</code>. */
protected ModelAndView onSubmit(HttpServletRequest request,
HttpServletResponse response, Object command, BindException errors)
throws ServletException {

NewArticleForm entryForm = (NewArticleForm) command;
Article entry = entryForm.getArticle();
logger.debug(entry.toString());
// delegate the insert to the Business layer
cManager.submitArticle(entry);
return new ModelAndView(getSuccessView(), "ownerId", entry
.getPostedBy().getId());
}

The related log messages are the followings:

DEBUG com.xyz.web.article.AddArticleFormController.showN ewForm:305 - Displaying new form
DEBUG com.xyz.web.article.AddArticleFormController.formB ackingObject:46 -
DEBUG com.xyz.web.article.AddArticleFormController.initB inder:58 -
DEBUG com.xyz.web.article.AddArticleFormController.showF orm:476 - Setting form session attribute [com.xyz.web.article.AddArticleFormController.FORM. articleForm] to: com.xyz.web.article.NewArticleForm@2ddc4c
DEBUG com.xyz.web.article.AddArticleFormController.refer enceData:38 -

The error occurs during the time of bringing up the form, but not submitting the form. I can't see any method other than the onSubmit where I can insert the errors.getModel() call.