Springboot Thymeleaf form submission showing NULL and blank values!! NOT showing entered values!

[Partha Ray]

Controller-> Design

@Slf4j
@Controller
@RequestMapping(value="/design")
public class ControllerDesignTaco 
{
	
	private static final Logger logger2= LoggerFactory.getLogger(ControllerDesignTaco.class);

	@GetMapping
	public String showDesignForm(Model obj_model_map)
	{ 
		List<DomainTacoIngredient> ingredients = Arrays.asList(
				new DomainTacoIngredient("FLTO", "Flour Tortilla", Type.WRAP),
				new DomainTacoIngredient("COTO", "Corn Tortilla", Type.WRAP),
				new DomainTacoIngredient("GRBF", "Ground Beef", Type.PROTEIN),
				new DomainTacoIngredient("CARN", "Carnitas", Type.PROTEIN),
				new DomainTacoIngredient("TMTO", "Diced Tomatoes", Type.VEGGIES),
				new DomainTacoIngredient("LETC", "Lettuce", Type.VEGGIES),
				new DomainTacoIngredient("CHED", "Cheddar", Type.CHEESE),
				new DomainTacoIngredient("JACK", "Monterrey Jack", Type.CHEESE),
				new DomainTacoIngredient("SLSA", "Salsa", Type.SAUCE),
				new DomainTacoIngredient("SRCR", "Sour Cream", Type.SAUCE)
				);
			
		Type types[] = DomainTacoIngredient.Type.values();
		for (Type type : types) 
		{
			
			System.out.println(obj_model_map.addAttribute(type.toString().toLowerCase(),
					filterByType(ingredients, type)));
			
			System.out.println(type.toString());
		}
				
		System.out.println(obj_model_map.addAttribute("design", new DomainTacoDesign()));
		
		Map<String, Object> obj_Map_model_map= obj_model_map.asMap();
		
		obj_Map_model_map.forEach((map_key,map_val)->
			System.out.println("key=" + map_key+ ",value="+ map_val)
		);
		
		
		return "design";
	}
	
       @PostMapping
	public String processDesign(
                /*@RequestBody*/ @Valid @ModelAttribute("design") DomainTacoDesign ingredient,
                BindingResult obj_binding_result1,
                Model obj_model_map, HttpServletRequest obj_http_servlet_request1,
                Errors obj_err1)
	{
		
		if(obj_binding_result1.hasErrors())
		{
			System.out.println(obj_binding_result1.getAllErrors());
		}

		if(obj_err1.hasErrors())
		{
			System.out.println(obj_err1.getAllErrors());
			
			return "design";
		}
		
		System.out.println(obj_http_servlet_request1.getParameterNames());
		
		Enumeration<String> obj_enum_strngs_obj_http_servlet_request1=
                                obj_http_servlet_request1.getParameterNames();
		
				for(Enumeration <String> objenumstr= obj_enum_strngs_obj_http_servlet_request1;
                                       obj_enum_strngs_obj_http_servlet_request1.hasMoreElements();)
				{
					System.out.println(objenumstr.nextElement());
				}
				
		
		System.out.println(obj_model_map.addAttribute("name",ingredient.getName()));
	
		
		System.out.println(obj_model_map.addAttribute("class",ingredient.getClass()));
		
	
		
		
		
		logger2.info("Processing design-> ingredient: {} ", ingredient);
		
		logger2.info("Processing design-> ingredient.name: {} ", ingredient.name);
	
		return "redirect:/orders/current";
	}
	
	
	

	private List<DomainTacoIngredient> filterByType(List<DomainTacoIngredient> ingredients, Type type) 
	{
		return ingredients.stream()
				.filter(x -> x.getType().equals(type))
				.collect(Collectors.toList());
		
	}	

when submitting design  form on localhost:

Form logs:

ingredients
name
{design=com.example.demo.DomainTacoDesign@3ee4d959, org.springframework.validation.BindingResult.design=org.springframework.validation.BeanPropertyBindingResult: 0 errors, name=null}
{design=com.example.demo.DomainTacoDesign@3ee4d959, org.springframework.validation.BindingResult.design=org.springframework.validation.BeanPropertyBindingResult: 0 errors, name=null, class=class com.example.demo.DomainTacoDesign}
2024-07-11T18:35:28.162-04:00  INFO 25076 --- [nio-8090-exec-9] com.example.demo.ControllerDesignTaco    : Processing design-> ingredient: com.example.demo.DomainTacoDesign@3ee4d959
2024-07-11T18:35:28.162-04:00  INFO 25076 --- [nio-8090-exec-9] com.example.demo.ControllerDesignTaco    : Processing design-> ingredient.name: null
{order=com.example.demo.DomainTacoOrder@2315f02}
key=order,value=com.example.demo.DomainTacoOrder@2315f02


designForm view Thymeleaf:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
	  xmlns:th="http://www.thymeleaf.org">
<head>
	<title>Taco Cloud</title>
</head>
<body>
	<h1>Design your taco!!</h1>
	<img />
	<form method="POST" th:object="${design}">
	<div class="grid">
		<div class="ingredient-group" id="wraps">
		<h3>Designate your wrap:</h3>
		<div th:each="ingredient : ${wrap}">
			<input name="ingredients" type="checkbox" th:value="${ingredient.id}"/>
			<span th:text="${ingredient.name}">INGREDIENT</span><br/>
		</div>
		</div>
		<div class="ingredient-group" id="proteins">
		<h3>Pick your protein:</h3>
		<div th:each="ingredient : ${protein}">
			<input name="ingredients" type="checkbox" th:value="${ingredient.id}"/>
			<span th:text="${ingredient.name}">INGREDIENT</span><br/>
		</div>
		</div>	
		<div class="ingredient-group" id="cheeses">
		<h3>Choose your cheese:</h3>
		<div th:each="ingredient : ${cheese}">
			<input name="ingredients" type="checkbox" th:value="${ingredient.id}"/>
		<span th:text="${ingredient.name}">INGREDIENT</span><br/>
		</div>
		</div>
		<div class="ingredient-group" id="veggies">
		<h3>Determine your veggies:</h3>
		<div th:each="ingredient : ${veggies}">
			<input name="ingredients" type="checkbox" th:value="${ingredient.id}"/>
			<span th:text="${ingredient.name}">INGREDIENT</span><br/>
		</div>
		</div>
		<div class="ingredient-group" id="sauces">
		<h3>Select your sauce:</h3>
		<div th:each="ingredient : ${sauce}">
			<input name="ingredients" type="checkbox" th:value="${ingredient.id}"/>
			<span th:text="${ingredient.name}">INGREDIENT</span><br/>
		</div>
		</div>
		</div>
		<div>
			
			
		<h3>Name your taco creation:</h3>
		<input type="text" th:field="*{name}"/>
		<br/>
		<button>Submit your taco</button>
		</div>
	</form>
			
</body>
</html>

[Steve M Davies]

<form method="POST" th:object="${design}">

Where are you sending the request to? Unless I am missing something you are merely attributing a POST method which will attempt to post the form on submit, but even if you are attempting to bind to the "design" model, you have no action attribute.

[Tim Holloway]

Note: code tags aren't just for code! They can also intelligently display/highlight XML, SQL, and many other types of structured text.

I've added code tags to the HTML template. Much easier to read that way.

[Tim Holloway]

OK. I edited it again because those long lines meant that I had to do a lot of right/left scrolling to read things. That, and the double-spaced lines mean that it's hard to read even on a wide screen like I'm using, though I left the double-spacing alone.

There are times when I long for the old 65-column punched-card, limitations.

[Tim Holloway]

Here's another helpful hint. When using data classes, override the toString method to make it format and display your data values. That makes it simpler to display what's in them. Some IDEs actually have a "wizard" that will generate that code for you.

And let me look at your loop:

        System.out.println(obj_http_servlet_request1.getParameterNames());
         
        Enumeration<String> obj_enum_strngs_obj_http_servlet_request1=
                                obj_http_servlet_request1.getParameterNames();
         
                for(Enumeration <String> objenumstr= obj_enum_strngs_obj_http_servlet_request1;
                                       obj_enum_strngs_obj_http_servlet_request1.hasMoreElements();)
                {
                    System.out.println(objenumstr.nextElement());
                }

Nah. I can't even tell what that's supposed to do. How about:

        final java.util.Map<java.lang.String, java.lang.String[]> parameterMap =
                 obj_http_servlet_request1.getParametergetParameterMap();

        for(String paramName; parameterMap.keySet() ) {
        {
              System.out.println("Parameter: " + paramName); // System out????????
              for ( String paramValue; parameterMap.get(paramName)) {
                  System.out.println("  " + paramValue); // Again, System out????????
              }
        }     

[Partha Ray]

Firstly sincere apologies for late response to both Steve M Davies and Tim Holloway. ..So briefly.... in an attempt to understand the logic of MVC pattern utilized in Spring deeply from ground up with added error objects + logs+ added essential annotations i am referring to example from said Spring Action book.. AND there seems to be quite a bit rather than just following the book to understand from ground up + also some of the utilities are outdaded..

Steve M Davies :
Yes added the action attribute to the respective form view fields of the respective Thymeleaf form Design. I have also added HTTP Client Request Server Response Logging via Logbook tool. Still null values:
2024-09-03T10:51:34.878-04:00  INFO 16712 --- [nio-8090-exec-5] com.example.demo.ControllerDesignTaco    : Processing design-> design: com.example.demo.DomainTacoDesign@1f4fa6cf
2024-09-03T10:51:34.878-04:00  INFO 16712 --- [nio-8090-exec-5] com.example.demo.ControllerDesignTaco    : Processing design-> design.name: null
2024-09-03T10:51:34.881-04:00 TRACE 16712 --- [nio-8090-exec-5] org.zalando.logbook.Logbook              : {"origin":"local","type":"response","correlation":"9fcc504f24c4bb84","duration":28,"protocol":"HTTP/1.1","status":302,"headers":{"Location":["http://localhost:8090/orders/current"]}}
2024-09-03T10:51:34.901-04:00 TRACE 16712 --- [nio-8090-exec-6] org.zalando.logbook.Logbook              : {"origin":"remote","type":"request","correlation":"d16495e3687de677","protocol":"HTTP/1.1","remote":"127.0.0.1","method":"GET","uri":"http://localhost:8090/orders/current","host":"localhost","path":"/orders/current","scheme":"http","port":"8090","headers":{"accept":["text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8"],"accept-encoding":["gzip, deflate, br"],"accept-language":["en-US,en;q=0.5"],"connection":["keep-alive"],"cookie":["username-localhost-8888=\"2|1:0|10:1725225514|23:username-localhost-8888|44:NTEzM2RlZDg5OTFjNDQ4ZGI1N2I5NTRkNjcwNzcwZmY=|67a14d89d1958ca89eaff312bd98d68bb898ed83e6a60b245bf4bdbdaca64f3c\"; _xsrf=2|1dcfd872|062cfe000619da61174c32d757eb076d|1725225514; JSESSIONID=DFBC5D013DFC886CA382E94A2F153F4F"],"host":["localhost:8090"],"referer":["http://localhost:8090/design"],"sec-fetch-dest":["document"],"sec-fetch-mode":["navigate"],"sec-fetch-site":["same-origin"],"sec-fetch-user":["?1"],"upgrade-insecure-requests":["1"],"user-agent":["Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/113.0"]}}

Tim Holloway:
Yes apologies the verbose object variable identifiers just for deep dive introspection purposes and also the excessive logging via tools and system.out. yes perhaps Map object for HTTP servlet Request with the getParameterMap method....and yes still null values when form submission as mentioned to Steve M Davies. Thanks for all your guys help.!