SpringBoot does not find error templates in production although it finds it in Netbeans - spring-boot

Question

During develepment (under Netbeans), if e.g. an internal server error appears in my java SpringBoot(2.1.3) project with jetty, I get the error page named 500.html that is located in the src/main/resources/templates/error/500.html :
Yet when deployed in production, the 500.html (same for 404.html) does not show because of
org.thymeleaf.exceptions.TemplateInputException: Error resolving template [/error/500], template might not exist or might not be accessible by any of the configured Template Resolvers
although the templates are located in the /BOOT-INF/classes/templates/error/ folder of the jar :
These templates are called in an error controller :
#Controller
public class MyErrorController implements ErrorController {
#RequestMapping("/error")
public String handleError(Model model, HttpServletRequest request) {
Object status = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
if (status != null) {
Integer statusCode = Integer.valueOf(status.toString());
model.addAttribute("errorCode",
statusCode);
if (statusCode == HttpStatus.NOT_FOUND.value()) {
return "/error/404";
} else if (statusCode == HttpStatus.INTERNAL_SERVER_ERROR.value()) {
return "/error/500";
}
}
return "/error/error";
}
#Override
public String getErrorPath() {
return "/error";
}
My project pom.xml features the spring-boot-maven-plugin as defined below :
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>2.1.3.RELEASE</version>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
Please note : all other templates can be found.
I read this other SO question but my project tree seems correct.
What should I do to make SpringBoot find my error templates ?
Any help appreciated,

Answer 1

In the controller above the path to the error pages is wrong. The path should not start with /. So instead of
if (statusCode == HttpStatus.NOT_FOUND.value()) {
return "/error/404";
} else if (statusCode == HttpStatus.INTERNAL_SERVER_ERROR.value()) {
return "/error/500";
}
}
return "/error/error";
the controller should be (without the leading /) :
if (statusCode == HttpStatus.NOT_FOUND.value()) {
return "error/404";
} else if (statusCode == HttpStatus.INTERNAL_SERVER_ERROR.value()) {
return "error/500";
}
}
return "error/error";
Please mind that still there should be one leading / in the getErrorPath() as shown in Baeldung's post :
#Override
public String getErrorPath() {
return "/error";
}