SpringBoot cannot find handler method - spring-boot

Question

I have a basic SpringBoot app. using Spring Initializer, embedded Tomcat, Thymeleaf template engine, and package as an executable JAR file.
this is the main class
#SpringBootApplication
public class TdkApplication {
public static void main(String[] args) {
SpringApplication.run(TdkApplication.class, args);
}
}
This is a controller
#Controller
public class MockupIndexController {
#RequestMapping("/mockup/index")
public String welcome(Map<String, Object> model) {
return "mockups/index";
}
}
This my pom.xml
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>com.tdk.iot.core</groupId>
<artifactId>tdk-core</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
But when I put this in the URL:
http://localhost:8080/mockup/index
I got the following log in the console
o.s.web.servlet.DispatcherServlet : Servlet 'dispatcherServlet' configured successfully
o.s.web.servlet.DispatcherServlet : DispatcherServlet with name 'dispatcherServlet' processing GET request for [/mockup/index]
s.w.s.m.m.a.RequestMappingHandlerMapping : Looking up handler method for path /mockup/index
s.w.s.m.m.a.RequestMappingHandlerMapping : Did not find handler method for [/mockup/index]
o.s.w.s.handler.SimpleUrlHandlerMapping : Matching patterns for request [/mockup/index] are [/**]
o.s.w.s.handler.SimpleUrlHandlerMapping : URI Template variables for request [/mockup/index] are {}
o.s.w.s.handler.SimpleUrlHandlerMapping : Mapping [/mockup/index] to HandlerExecutionChain with handler [ResourceHttpRequestHandler [locations=[ServletContext resource [/], class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver#8b91134]]] and 1 interceptor
o.s.web.servlet.DispatcherServlet : Last-Modified value for [/mockup/index] is: -1
o.s.web.servlet.DispatcherServlet : Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
o.s.web.servlet.DispatcherServlet : Successfully completed request
o.s.web.servlet.DispatcherServlet : DispatcherServlet with name 'dispatcherServlet' processing GET request for [/error]
s.w.s.m.m.a.RequestMappingHandlerMapping : Looking up handler method for path /error

Answer 1

I assume your controller class is not found during scanning cause it is in a package that will not be scanned by default. I guess your application is in something like com.tdk.app and your controller in com.tdk.controller, right? If yes just move the app one level up to com.tdk and your issue should go away.

Answer 2

The controller package should be the one level bottom package of "TdkApplication" if your "TdkApplication" is in com.test package, Then your controller should be under com.test.controller package. Means one level down package when we comparing with application package

Answer 3

following will work
App package should be like com.app
then controller would be com.app.controller.
if you use it like below then spring would be unable to scan the controller
App package: com.app.main
controller:com.app.controller