Lab 5: Return String via HTTP GET

Spring Annotation Reference

This reference of annotations might be helpful: http://engineering.pivotal.io/post/must-know-spring-boot-annotations-controllers/

Goal¶

Return a String response for a GET request to an endpoint.

Clean Up¶

Before moving on, delete the following classes as we don't need them anymore in their present form:

CoffeeOrderComponent
CoffeeOrderController
CoffeeOrderRestController
CoffeeOrderSecondComponent
CoffeeOrderService

Make sure the tests still run before moving on.

a. Integration Test¶

Add the following new test class, CoffeeMenuWebTest in the same directory location as the existing CoffeeKioskApplicationTests class.

package com.tedmyoung.coffeekiosk;

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import org.springframework.test.web.servlet.MockMvc;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@WebMvcTest(CoffeeMenuController.class)
public class CoffeeMenuWebTest {

  @Autowired
  private MockMvc mockMvc;

  @Test
  public void getCoffeeSizesReturnsOk() throws Exception {
    mockMvc.perform(get("/api/coffee/menu/sizes")
                        .accept(MediaType.APPLICATION_JSON))
           .andExpect(status().isOk());
  }
}

Create a new class in the production code directory called CoffeeMenuController like this:

package com.tedmyoung.coffeekiosk;

import org.springframework.web.bind.annotation.RestController;

@RestController
public class CoffeeMenuController {
}

Run this test, and you will see it fail with a 404 status code (Not Found).

b. GET Mapped Endpoint¶

To make the test pass, create a new method that takes no parameters and returns a String. Add an @GetMapping("/api/coffee/menu/sizes") annotation before the method. Inside the method, return the string small. It will look like this:

@GetMapping("/api/coffee/menu/sizes")
public String getCoffeeSizes() {
  return "small";
}

Now run the test, and it should pass.

Browser¶

Try it from the browser as well by running the application and pointing your browser to:

http://localhost:8080/api/coffee/menu/sizes

Glossary

Endpoint: a URL that responds to HTTP requests
Mapping: the routing of an incoming request to a method based on a string defining the path
@RestController: Component annotation for class containing Mappings
@GetMapping: method annotation for mapping an incoming GET request to a method