1. SimpleFormController vs @Controller

In XML-based Spring MVC web application, you create a form controller by extending the SimpleFormController class.

In annotation-based, you can use @Controller instead.

SimpleFormController

public class CustomerController extends SimpleFormController{
           //...}

Annotation

@Controller@RequestMapping("/customer.htm")public class CustomerController{
           //...}

 

2. formBackingObject() vs RequestMethod.GET

In SimpleFormController, you can initialize the command object for binding in the formBackingObject() method. In annotation-based, you can do the same by annotated the method name with @RequestMapping(method = RequestMethod.GET).

SimpleFormController

@Override	protected Object formBackingObject(HttpServletRequest request)		throws Exception {
      		Customer cust = new Customer();		//Make "Spring MVC" as default checked value		cust.setFavFramework(new String []{
     "Spring MVC"}); 		return cust;	}

Annotation

@RequestMapping(method = RequestMethod.GET)	public String initForm(ModelMap model){
      		Customer cust = new Customer();		//Make "Spring MVC" as default checked value		cust.setFavFramework(new String []{
     "Spring MVC"}); 		//command object		model.addAttribute("customer", cust); 		//return form view		return "CustomerForm";	}

3. onSubmit() vs RequestMethod.POST

In SimpleFormController, the form submission is handle by the onSubmit() method. In annotation-based, you can do the same by annotated the method name with @RequestMapping(method = RequestMethod.POST).

SimpleFormController

@Override	protected ModelAndView onSubmit(HttpServletRequest request,		HttpServletResponse response, Object command, BindException errors)		throws Exception {
      		Customer customer = (Customer)command;		return new ModelAndView("CustomerSuccess"); 	}

Annotation

@RequestMapping(method = RequestMethod.POST)	public String processSubmit(		@ModelAttribute("customer") Customer customer,		BindingResult result, SessionStatus status) {
      		//clear the command object from the session		status.setComplete();  		//return form success view		return "CustomerSuccess"; 	}

4. referenceData() vs @ModelAttribute

In SimpleFormController, usually you put the reference data in model via referenceData() method, so that the form view can access it. In annotation-based, you can do the same by annotated the method name with @ModelAttribute.

SimpleFormController

@Override	protected Map referenceData(HttpServletRequest request) throws Exception {
      		Map referenceData = new HashMap(); 		//Data referencing for web framework checkboxes		List
      
        webFrameworkList = new ArrayList
       
        ();		webFrameworkList.add("Spring MVC");		webFrameworkList.add("Struts 1");		webFrameworkList.add("Struts 2");		webFrameworkList.add("JSF");		webFrameworkList.add("Apache Wicket");		referenceData.put("webFrameworkList", webFrameworkList); 		return referenceData;	}
       
      

Spring’s form

Annotation

@ModelAttribute("webFrameworkList")	public List
      
        populateWebFrameworkList() {
      		//Data referencing for web framework checkboxes		List
       
         webFrameworkList = new ArrayList
        
         ();		webFrameworkList.add("Spring MVC");		webFrameworkList.add("Struts 1");		webFrameworkList.add("Struts 2");		webFrameworkList.add("JSF");		webFrameworkList.add("Apache Wicket"); 		return webFrameworkList;	}
        
       
      

Spring’s form

5. initBinder() vs @InitBinder

In SimpleFormController, you define the binding or register the custom property editor via initBinder() method. In annotation-based, you can do the same by annotated the method name with @InitBinder.

SimpleFormController

protected void initBinder(HttpServletRequest request,		ServletRequestDataBinder binder) throws Exception {
      		SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");		binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true));    }

Annotation

@InitBinder	public void initBinder(WebDataBinder binder) {
     		SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd"); 		binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true));	}

From Validation

In SimpleFormController, you have to register and map the validator class to the controller class via XML bean configuration file, and the validation checking and work flows will be executed automatically.

In annotation-based, you have to explicitly execute the validator and define the validation flow in the @Controller class manually. See the different :

SimpleFormController

Annotation

@Controller@RequestMapping("/customer.htm")public class CustomerController{
      	CustomerValidator customerValidator; 	@Autowired	public CustomerController(CustomerValidator customerValidator){
     		this.customerValidator = customerValidator;	} 	@RequestMapping(method = RequestMethod.POST)	public String processSubmit(		@ModelAttribute("customer") Customer customer,		BindingResult result, SessionStatus status) {
      		customerValidator.validate(customer, result); 		if (result.hasErrors()) {
     			//if validator failed			return "CustomerForm";		} else {
     			status.setComplete();			//form success			return "CustomerSuccess";		}	}	//...

Full Example

See a complete @Controller example.

package com.mkyong.customer.controller; import java.sql.Date;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.LinkedHashMap;import java.util.List;import java.util.Map; import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.propertyeditors.CustomDateEditor;import org.springframework.stereotype.Controller;import org.springframework.ui.ModelMap;import org.springframework.validation.BindingResult;import org.springframework.web.bind.WebDataBinder;import org.springframework.web.bind.annotation.InitBinder;import org.springframework.web.bind.annotation.ModelAttribute;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.support.SessionStatus; import com.mkyong.customer.model.Customer;import com.mkyong.customer.validator.CustomerValidator; @Controller@RequestMapping("/customer.htm")public class CustomerController{
      	CustomerValidator customerValidator; 	@Autowired	public CustomerController(CustomerValidator customerValidator){
     		this.customerValidator = customerValidator;	} 	@RequestMapping(method = RequestMethod.POST)	public String processSubmit(		@ModelAttribute("customer") Customer customer,		BindingResult result, SessionStatus status) {
      		customerValidator.validate(customer, result); 		if (result.hasErrors()) {
     			//if validator failed			return "CustomerForm";		} else {
     			status.setComplete();			//form success			return "CustomerSuccess";		}	} 	@RequestMapping(method = RequestMethod.GET)	public String initForm(ModelMap model){
      		Customer cust = new Customer();		//Make "Spring MVC" as default checked value		cust.setFavFramework(new String []{
     "Spring MVC"}); 		//Make "Make" as default radio button selected value		cust.setSex("M"); 		//make "Hibernate" as the default java skills selection		cust.setJavaSkills("Hibernate"); 		//initilize a hidden value		cust.setSecretValue("I'm hidden value"); 		//command object		model.addAttribute("customer", cust); 		//return form view		return "CustomerForm";	}  	@ModelAttribute("webFrameworkList")	public List
      
        populateWebFrameworkList() {
      		//Data referencing for web framework checkboxes		List
       
         webFrameworkList = new ArrayList
        
         ();		webFrameworkList.add("Spring MVC");		webFrameworkList.add("Struts 1");		webFrameworkList.add("Struts 2");		webFrameworkList.add("JSF");		webFrameworkList.add("Apache Wicket"); 		return webFrameworkList;	} 	@InitBinder	public void initBinder(WebDataBinder binder) {
     		SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd"); 		binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true)); 	} 	@ModelAttribute("numberList")	public List
         
           populateNumberList() {
      		//Data referencing for number radiobuttons		List
          
            numberList = new ArrayList
           
            (); numberList.add("Number 1"); numberList.add("Number 2"); numberList.add("Number 3"); numberList.add("Number 4"); numberList.add("Number 5");  return numberList; }  @ModelAttribute("javaSkillsList") public Map
            
              populateJavaSkillList() {   //Data referencing for java skills list box Map
             
               javaSkill = new LinkedHashMap
              
               (); javaSkill.put("Hibernate", "Hibernate"); javaSkill.put("Spring", "Spring"); javaSkill.put("Apache Wicket", "Apache Wicket"); javaSkill.put("Struts", "Struts");  return javaSkill; }  @ModelAttribute("countryList") public Map
               
                 populateCountryList() {   //Data referencing for java skills list box Map
                
                  country = new LinkedHashMap
                 
                  (); country.put("US", "United Stated"); country.put("CHINA", "China"); country.put("SG", "Singapore"); country.put("MY", "Malaysia");  return country; }}
                 
                
               
              
             
            
           
          
         
        
       
      

To make annotation work, you have to enable the component auto scanning feature in Spring.

      
        	
        	
         	
       	
       		
        	
        	
                     
                         
         
          /WEB-INF/pages/
                       
                      
                         
         
          .jsp
                       
                
       
      

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