Dynamic form and data binding with Spring MVC

Question

In my Spring MVC application I need to implement a dynamic questionnaire form: I have N questions and for each I have 3 options.

So in my page I\'ll have something like

Answer 1

how to post data and handle ModelAttribute binding in this scenario

you can do,

i am considering Question class like:

public class Question {
    private String question;
    private Map optionMap;
    private Integer selectedOptionKey;
        //getters and setters
}

and Option class like:

public class Option {

    private Integer optionKey;
    private String optionText;

    //getters and setters
}

and one QuestionsModel class for form binding like:

public class QuestionsModel {
    private Map questionMap;
    //getters and setters
}

and inside Controller class GET handler method, populate questions for example:

@RequestMapping(method=RequestMethod.GET)
    public String index(Model model){                
    Option optionA = new Option(1, "A");
    Option optionB = new Option(2, "B");
    Option optionC = new Option(3, "C");

    Map optionMap = new HashMap();
    optionMap.put(optionA.getOptionKey(),optionA);
    optionMap.put(optionB.getOptionKey(),optionB);
    optionMap.put(optionC.getOptionKey(),optionC);

    Question question1 = new Question("A Q", optionMap, 1);
    Question question2 = new Question("B Q", optionMap, 1);
    Question question3 = new Question("C Q", optionMap, 1);
    Map questionMap = new HashMap();
    questionMap.put(1, question1);
    questionMap.put(2, question2);
    questionMap.put(3, question3);

    model.addAttribute("questionsModel", new QuestionsModel(questionMap));

    return "index";
}

finally in jsp page use to keep old values, and render form elements like:

    
        

    

        
Question
        
Options
        
    
   
    

            

                
                Question:

            
            

            
                
                

                

            

             
        
    
    
    

you can receive binding and model in POST like:

@RequestMapping(value="/questionPost", method=RequestMethod.POST)
public String indexPost(@ModelAttribute("questionsModel") QuestionsModel questionModel, BindingResult result){
    System.out.println(questionModel.getQuestionMap());

    return "redirect:/";
}