Spring Boot API with Multiple Controllers?

Question

I am starting to learn Spring Boot. I am struggling to find an example with multiple RestControllers, which indicates to me that I may be doing something wrong. I am trying a very simple example: The goal is to make calls like the following:

localhost:8080/
localhost:8080/employees/bob
localhost:8080/departments

I can only get localhost:8080/ to display. The other calls return response: This application has no explicit mapping for /error, so you are seeing this as a fallback.

com.demo.departments
Department.java
DepartmentController.java

com.demo.employees
Employee.java
EmployeeController.java

com.demo
BootDemoApplication.java

Code:

package com.demo.departments
@RestController
@RequestMapping("/departments")
public class DepartmentController {


@RequestMapping("")
public String get(){
    return "test..";

}

@RequestMapping("/list")
public List<Department> getDepartments(){
    return null;

}

}
--------------------------------------------------------------------
package com.demo.employees
@RestController
@RequestMapping("/employees")
public class EmployeeController {

Employee e =new Employee();

@RequestMapping(value = "/{name}", method = RequestMethod.GET, produces = "application/json")
public Employee getEmployeeInJSON(@PathVariable String name) {

 e.setName(name);
 e.setEmail("employee1@genuitec.com");

 return e;

}
}
-----------------------------------------------------------------------

package com.demo
@RestController
@SpringBootApplication

public class BootDemoApplication {

public static void main(String[] args) {
    SpringApplication.run(BootDemoApplication.class, args);
}

@RequestMapping("/")
String home(){
    return "<html> This is the home page for Boot Demo.</html>";
}

I don't think you need the preceeding "/" on the top level controller mappings. — ChiefTwoPencils, May 22 '16 at 05:57
This should work (tested it out). You didn't provide any controller for `http://localhost:8080/` though, so perhaps the mistake is there. — g00glen00b, May 22 '16 at 12:16
You are returning JSON, but aren't requesting it (the browser expect HTML) so no method for handling the request is found. — M. Deinum, May 22 '16 at 14:16
Yes I am, Employee is a POJO. Its not calling any of the code in the other 2 classes in the debugger. It complains about mapping, not about results. — user1529412, May 22 '16 at 15:14
Do you see any other errors in logs or in the console? If you run via gradle, try adding `-i` option — Nikem, May 22 '16 at 15:18
I run it as spring boot app from eclipse. It builds fine, it maps localhost:8080 fine too and return the html message. The other two controllers that produce the mapping error, when I do localhost:8080/employees/bob or localhost:8080/departments. Does anyone have a link for a similar example I can follow? I am just looking to do localhost/foo & localhost/bar, where foo and bar are separate controller classes in different packages. — user1529412, May 22 '16 at 15:34
@user1529412 Your example works... I created a new Spring boot project, added spring-boot-starter-web and only copy pasted the classes you mentioned above. It works. — g00glen00b, May 23 '16 at 05:48
@g00glen00b, I am not sure how you getting it to work. When I type in http://localhost:8181/employees/bob into the browser, I get "This application has no explicit mapping for /error, so you are seeing this as a fallback.", but if I do "localhost:8181", I get the correct html response message. — user1529412, May 24 '16 at 01:51
I just made a new project and pasted all your code in it, it works: https://www.dropbox.com/s/acis5aem4lbpd73/demo.zip?dl=0 — g00glen00b, May 24 '16 at 05:47
@g00glen00b, I am curious, how are you running the code, I exported it to Eclipse and ran it as spring boot project , still same problem. I think eclipse may be the problem. — user1529412, May 25 '16 at 02:31

VietDD · Answer 1 · 2017-08-05T12:18:10.343

I'm trying Spring Boot and got same problem, and just fixed it, I post my solution here because I think it maybe helpful for someone.

First, put application class ( which contain main method) at the root of controllers's package:

com.example.demo
              |
              +-> controller
              |      |
              |      +--> IndexController.java
              |      +--> LoginController.java
              |
              +-> Application.java

Application.java

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Spring will scan all the components of sub-packages of demo package

IndexController.java (return index.html view)

package com.example.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping(value = {""})
public class IndexController {

    @GetMapping(value = {""})
    public ModelAndView index() {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        return modelAndView;
    }

}

LoginController.java (return login.html view)

package com.example.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping(value = {"/login"})
public class LoginController {
    @GetMapping(value = {""})
    public ModelAndView login() {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("login");
        return modelAndView;
    }
}

And now I can enter Index view : http://localhost:8080/demo/ and Login view : http://localhost:8080/demo/login

user1529412 · Accepted Answer · 2016-05-26T02:17:55.133

13

Apparently Controllers in different packages can't be seen with @springbootApplication notation in the main class. The solution explained here, https://kamwo.me/java-spring-boot-mvc-ontroller-not-called/.

edited May 26 '16 at 02:17

answered May 25 '16 at 03:21

user1529412

3,616
7
26
42

Ian Riley · Answer 3 · 2016-09-01T18:55:08.950

For Spring-boot 1.3.x and up, passing a base package to SpringBootApplication should work:

@SpringBootApplication(scanBasePackages = {"com.demo"})
public class DemoBootApplication {
    // code
}

This worked for me on a similar application using spring-boot 1.4.0. For earlier versions of spring-boot, it appears you'll have forego using SpringBootApplication and instead use the following to get same effect as above:

@Configuration
@EnableAutoConfiguration
@ComponentScan(basePackages = {"com.demo"})
public class DemoBootApplication {
    // code
}

I found this in the comments on this blog post.

score 4 · Answer 4 · answered Jan 30 '18 at 16:26

4

Make sure that the @SpringBootApplication class is in a package which is a level above all other packages that contain @RestControllers, or in the same package.

answered Jan 30 '18 at 16:26

Janac Meena

3,203
35
32

score 1 · Answer 5 · answered Jun 05 '17 at 06:21

ComponentScan annotation works in most cases.

See below example, you could apply similar.
package com.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@ComponentScan(basePackages = {"com.demo"})
@SpringBootApplication
public class DemoApplication {

public static void main(String[] args) {
    SpringApplication.run(DemoApplication.class, args);
}
}

score 0 · Answer 6 · edited Dec 07 '16 at 00:40

Try this

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Main {

    public static void main(String[] args) {

        Object[] sources = new Object[2];
        sources[0] = Controller1.class;
        sources[1] = Controller2.class;
        SpringApplication.run(sources, args);
    }

}

score 0 · Answer 7 · answered Feb 28 '19 at 17:58

0

I'm not sure if this is the right way to do it, but when I changed my 2nd Controllers annotation from @Controller to @RestController it started working.

answered Feb 28 '19 at 17:58

jovanchohan

143
2
3

score -1 · Answer 8 · answered May 22 '16 at 06:57

Try below:-

@ComponentScan
@Configuration
@EnableAutoConfiguration
public class BootDemoApplication {

public static void main(String[] args) {

    SpringApplication.run(BootDemoApplication.class);
}
}

@RestController
@RequestMapping(value = "test", produces =    MediaType.APPLICATION_JSON_VALUE)
public class TestController {

@RequestMapping(method = RequestMethod.GET)
public String test() {
    return "from test method";
}

}

Spring Boot API with Multiple Controllers?

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