How to get Thymeleaf to parse boolean for SpringBootMVC? [ThymeLeaf-SpringBoot-Java17]

Question

So I have a hardcoded true/false value in HTML so I can use that to fill the E.bool value for one of my entities after the HTML form submits (POST).

HTML

// I tried
<select id="isBool" name="isBool" class="form-select" aria-label="select">
  <option value="1">true option</option>
  <option value="0">false option</option>
</select>
// then I tried
<select id="isBool" name="isBool" class="form-select" aria-label="select">
  <option th:value="1">true option</option>
  <option th:value="0">false option</option>
</select>
// then I tried
<select id="isBool" name="isBool" class="form-select" aria-label="select">
  <option th:value="${true}">true option</option>
  <option th:value="${false}">false option</option>
</select>

Entity

@Entity
@Table
public class E {
  ..
  @Column
  boolean bool
  ..
}

Controller

public String addE(@Valid E e, BindingResult result, HttpServletRequest request, Model model) {
  ...
  // no matter what, E has bool = false here :(
  ...
}

What am I doing wrong? No matter what I try, it's always false.

The craziest thing is that I can literally go to my IntelliJ and see in the debugger, that the request.parameters has the correct value right there! What's going on? Why is ThymeLeaf/Spring being so difficult? Is there any easier way to get a boolean like this through the controller?

Answer 1

Amazingly, it was the getters fault for the boolean member field. My IDE generated it as "isBool" instead of "getBool" and apparently Thymeleaf only looks for literal getters and setters.