java - BindingResult isn't detecting annotation based constraints and errors -

the validation errors don't show reason. in fact, binding result doesn't return errors. bean follows:

@notblank @size(min = 5, max = 20, message = "user id must 5 20 characters long.") @pattern(regexp = "^[a-za-z0-9]+$", message = "user id must alphanumeric.") public string getusername() {     return username; }  public void setusername(string username) {     this.username = username; }  @notblank @size(min = 6, max = 20, message = "the password must between 6 20 characters long.") public string getpassword() {     return password; }  public void setpassword(string password) {     this.password = password; } 

my controller class has following variable:

private beanvalidator beanvalidator = new beanvalidator(new annotationbeanvalidationconfigurationloader()); 

there method in controller handles binding.

beanvalidator.validate(userlogin, bindingresult);  if(bindingresult.haserrors()) {     return "/"; } else      return "/homepage"; 

when login using blank credentials values of username , password, system logs in. evidently, bindingresult isn't detecting errors. help?

i used @valid instead of implementing own validator. also, parameter has in following order:

public string homepage(@modelattribute(value="userlogin") @valid userlogin userlogin, bindingresult bindingresult, model model) {//your code} 

mind order of @valid bean parameter , bindingresult parameter. bindingresult should placed after @valid parameter otherwise error displayed.