Spring - JSP form:input on jsp page error: jasperexception - spring

Question

When I put the code inside the form:form tag on view cadastro.jsp:
<div class="form-group">
<label for="nome" class="col-sm-2 control-label"> name Project: </ label>
<div class="col-sm-10">
<input for="nome" class="form-control" />
<form:errors path="nome" />
</div>
</div>
Its works
but when i put
<div class="form-group">
<label for="nome" class="col-sm-2 control-label"> Nome do Projeto: </ label>
<div class="col-sm-10">
<form:input cssClass="form-control" path="nome" />
<form:errors path="nome" />
</div>
</div>
not work because the form: input tag
Error:
HTTP Status 500 - An exception occurred processing JSP page /WEB-INF/view/cadastro.jsp at line 34
ProjetroController
#RequestMapping(value = "/novoProjeto", method = RequestMethod.POST)
public String adicionarProjeto(#Valid #ModelAttribute("projeto") Projeto projeto, BindingResult result) {
if(result.hasErrors()) {
return("cadastro");
}
projeto.setStatus("NOVO");
this.pc.salvar(projeto);
return "redirect:/listar";
}

Answer 1

I think you need to add a <form:form> tag around your form, as follows:
<form:form>
<div class="form-group">
<label for="nome" class="col-sm-2 control-label"> Nome do Projeto: </ label>
<div class="col-sm-10">
<form:input cssClass="form-control" path="nome" />
<form:errors path="nome" />
</div>
</div>
</form:form>
In Spring official documentation, it states that:
All the other tags in this library are nested tags of the form tag.

Answer 2

you have to import spring form taglib inorder to use elemnets of spring form like:
add this in top of your jsp
<%# taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
then, you can use like:
<form:form id="myForm" method="post" action="/someAction" modelAttribute="formBean">
<form:label path="name"/>
<form:input path="name"/>
<form:form>
and you have add modelAttribute/command object in controller like:
#RequestMapping(value="/someUrl", method=RequestMethod.GET)
public String showForm(Model model){
model.addAttribute("formBean", new FormBean());
return "someViewName";
}
and FormBean class looks like:
public class FormBean {
private String name;
public FormBean(){} //default constructor
//getter and setter for name
}