hibernate - Spring validator - The request sent by the client was syntactically incorrect -

my friend helped me set first spring/hibernate project , trying implement custom validator. have registrationform model uses anotations validate. however, need implement password validator - check if password , confirmpassword equal.

problem: when post, if passwords match, data saved. if dont match, @ validators following line, error title.

errors.rejectvalue("confirmpassword", "valid.passwordconfdiff"); 

the request sent client syntactically incorrect.

tutorial followed: http://examples.javacodegeeks.com/enterprise-java/spring/mvc/spring-mvc-password-example/

this have:

controller:

@controller @requestmapping("/") //@sessionattributes(value = {"registerform"}) @componentscan("ba.codecentric.movienight") public class frontcontroller {      @autowired     private userservice userservice;      @autowired       @qualifier("passwordvalidator")     private passwordvalidator validator;      @initbinder("password")     private void initbinder(webdatabinder binder) {             binder.setvalidator(validator);         }      @requestmapping(method = requestmethod.get)     public string initindex(model model){                model.addattribute("registerform", new registerform());          password password = new password();         model.addattribute("password", password);          return "index";     }      @requestmapping(value="/register", method=requestmethod.post)     public string addnewuser(@valid @modelattribute("registerform") registerform registerform,                bindingresult result, model model, httpservletrequest request, @validated password password){          if(result.haserrors()){             model.addattribute("error", true);             model.addattribute("userisregistering", "<script>$('#loginbox').hide(); $('#signupbox').show();</script>");             system.out.println("error");             return "index";         }          user user = new user();          user.setusername(registerform.getusername());         user.setpassword(registerform.getpassword());                 userservice.addnewuser(user);          return "index";     }        } 

password validator:

     public class passwordvalidator implements validator{       public boolean supports(class<?> paramclass) {         return password.class.equals(paramclass);        }      public void validate(object obj, errors errors) {          password password = (password) obj;          if (!password.getpassword().equals(password.getconfirmpassword())) {                 errors.rejectvalue("confirmpassword", "valid.passwordconfdiff");                 }      } } 

registrationform:

public class registerform {             @notblank             @notempty              private string username;             @notblank             @notempty              @size(min=7,max=16,message="password range error")             private string password;              @notblank             @notempty             private string confirmpassword;         //getters setters         } 

registration form jsp:

 <form:form id="signupform" class="form-horizontal" role="form" commandname="registerform" action="${pagecontext.request.contextpath}/register" method="post">                              <form:errors path="*" cssclass="errorblock" element="div" class="alert alert-danger" role="alert"  />                              <div class="form-group">                                 <label for="username" class="col-md-3 control-label">user name</label>                                 <div class="col-md-9">                                     <form:input type="text" path="username" class="form-control" name="username" placeholder="user name" />                                 </div>                             </div>                              <form:errors path="username" element="div" class="alert alert-danger" role="alert" />                              <div class="form-group">                                                             <label for="password" class="col-md-3 control-label">password</label>                                 <div class="col-md-9">                                     <form:password path="password" class="form-control" name="password" placeholder="password"/>                                 </div>                             </div>                              <form:errors path="password" element="div" class="alert alert-danger" role="alert" />                              <div class="form-group">                                 <label for="confirmpassword" class="col-md-3 control-label">confirm password</label>                                 <div class="col-md-9">                                     <form:password path="confirmpassword" class="form-control" name="confirmpassword" placeholder="confirm password"/>                                 </div>                             </div>                                                                                              <form:errors path="confirmpassword" class="alert alert-danger" role="alert" />                              <div class="form-group">                                 <!-- button -->                                                                         <div class="col-md-offset-3 col-md-9">                                     <form:button id="btn-signup" type="submit" class="btn btn-info"><i class="icon-hand-right"></i> &nbsp sign up</form:button>                                                                         </div>                             </div>                                                                                                     </form:form> 

i have faced same problem.

@requestmapping(method = requestmethod.post) public string processform(         @valid @modelattribute("student") student student, model model,         bindingresult result) {     if (result.haserrors()) {         return "registration";     }     return "success"; } 

when object student has invalid attribute(s), code gives error: request sent client syntactically incorrect.

however, if order of arguments student , model changed, method works expected. e.g.,

public string processform(model model, @valid @modelattribute("student") student student, bindingresult result)

and

public string processform( @valid @modelattribute("student") student student, bindingresult result, model model) both work expected.

please, let me know science behind this.