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Testing Spring Boot REST Controller Response Handling in spring-boot-examples

This test suite demonstrates Spring Boot REST controller testing using MockMvc for a basic Hello World endpoint. It validates the HTTP response and content matching through Spring’s testing framework while showcasing standalone controller test configuration.

Test Coverage Overview

The test suite focuses on validating a simple REST endpoint’s behavior in isolation.

Key areas covered include:

HTTP GET request handling
Response status code verification
Response content validation
JSON media type acceptance

Implementation Analysis

The testing approach utilizes Spring’s MockMvc framework for simulating HTTP requests without a full server deployment. The implementation leverages standalone setup pattern with MockMvcBuilders, enabling focused controller testing without loading the complete application context.

Key patterns include:

MockMvc request building
Fluent assertion chaining
Standalone controller initialization

Technical Details

Testing stack components:

SpringRunner for test execution
MockMvc for request simulation
SpringBootTest annotation for configuration
JUnit 4 as the base testing framework
Hamcrest matchers for assertions
MockMvcRequestBuilders for request construction

Best Practices Demonstrated

The test class exemplifies several testing best practices in the Spring ecosystem.

Notable practices include:

Proper test setup isolation using @Before
Clear test method naming
Focused controller testing without dependencies
Explicit media type specification
Clean assertion structure

ityouknow/spring-boot-examples

1.x/spring-boot-helloWorld/src/test/java/com/neo/controller/HelloTests.java

            
package com.neo.controller;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.mock.web.MockServletContext;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;

import static org.hamcrest.Matchers.equalTo;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@RunWith(SpringRunner.class)
@SpringBootTest
public class HelloTests {

	
    private MockMvc mvc;

    @Before
    public void setUp() throws Exception {
        mvc = MockMvcBuilders.standaloneSetup(new HelloWorldController()).build();
    }

    @Test
    public void getHello() throws Exception {
        mvc.perform(MockMvcRequestBuilders.get("/hello").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("Hello World")));
    }

}