fix test

SpringBootTest/src/test/java/com/example/MockMvcTest.java

@@ -30,8 +30,8 @@ public class MockMvcTest {
 
     @Test
     public void test() throws Exception {
-        TestMessage message = new TestMessage("wonchul", 0);
-        String result = mapper.writeValueAsString(message);
+        final TestMessage message = new TestMessage("wonchul", 0);
+        final String result = mapper.writeValueAsString(message);
 
         given(service.jsonTest())
                 .willReturn(message);

SpringBootTest/src/test/java/com/example/MockTest.java → SpringBootTest/src/test/java/com/example/MockitoBeanTest.java

@@ -12,7 +12,7 @@
 import static org.mockito.BDDMockito.given;
 
 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
-public class MockTest {
+public class MockitoBeanTest {
 
     @Autowired
     TestRestTemplate restTemplate;
@@ -25,7 +25,7 @@ public void test() {
         given(service.test(0))
                 .willReturn("Spring Boot Service Test");
 
-        String result = restTemplate.getForObject("/test?flag=0", String.class);
+        final String result = restTemplate.getForObject("/test?flag=0", String.class);
         assertThat(result)
                 .isEqualTo("Spring Boot Service Test");
     }

SpringBootTest/src/test/java/com/example/TestBeanTest.java

@@ -0,0 +1,51 @@
+package com.example;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.example.domain.TestMessage;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.test.context.bean.override.convention.TestBean;
+
+import com.example.service.BasicService;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+public class TestBeanTest {
+
+    @Autowired
+    TestRestTemplate restTemplate;
+
+    @TestBean
+    BasicService basicService;
+
+    static BasicService basicService() {
+        return new BasicService() {
+            @Override
+            public String test(int flag) {
+                return "Spring Boot Service Test";
+            }
+
+            @Override
+            public TestMessage jsonTest() {
+                throw new UnsupportedOperationException("jsonTest not implemented");
+            }
+        };
+    }
+
+    @Test
+    public void mvcTest() {
+        final String result = restTemplate.getForObject("/test?flag=0", String.class);
+        assertThat(result)
+                .isEqualTo("Spring Boot Service Test");
+    }
+
+    @Test
+    public void serviceTest() {
+        assertThat(basicService.test(0))
+                .isEqualTo("Spring Boot Service Test");
+    }
+}