Using a select field

In this recipe, you will learn how to display a select field. When the form is submitted, retrieve the selected value in a controller method.

How to do it…

1. In the controller, add a @ModelAttribute method returning a Map object that contains the select field options:

   @ModelAttribute("countries")
   public Map<String, String>countries() {
     Map<String, String> m = new HashMap<String, String>();
     m.put("us", "United States");
     m.put("ca", "Canada");
     m.put("fr", "France");
     m.put("de", "Germany");
     return m;
   }

2. If a default value is necessary, use a String attribute of the default object (refer to the Setting a form's default values using a model object recipe) initialized with one of the Map keys:

   user.setCountry("ca");

3. In the JSP, use a form:select element initialized with the @ModelAttribute Map:

   <form:select path="country" items="${countries}" />

4. In the controller that processes the form submission, make sure that the @ModelAttribute object (the one...