Add JUnit 4 and the Vintage Engine sample

This commit adds a sample to verify the use of JUnit 4 and the Vintage
Engine.

See gh-17100

spring-boot-samples/pom.xml

@@ -57,6 +57,7 @@
 		<module>spring-boot-sample-jta-bitronix</module>
 		<module>spring-boot-sample-jta-jndi</module>
 		<module>spring-boot-sample-junit-jupiter</module>
+		<module>spring-boot-sample-junit-vintage</module>
 		<module>spring-boot-sample-kafka</module>
 		<module>spring-boot-sample-liquibase</module>
 		<module>spring-boot-sample-logback</module>

spring-boot-samples/spring-boot-sample-junit-vintage/pom.xml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<!-- Your own application should inherit from spring-boot-starter-parent -->
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-samples</artifactId>
+		<version>${revision}</version>
+	</parent>
+	<artifactId>spring-boot-sample-junit-vintage</artifactId>
+	<name>Spring Boot JUnit Vintage Sample</name>
+	<description>Spring Boot JUnit Vintage Sample</description>
+	<properties>
+		<main.basedir>${basedir}/../..</main.basedir>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.jupiter</groupId>
+					<artifactId>junit-jupiter</artifactId>
+				</exclusion>
+				<exclusion>
+					<groupId>org.mockito</groupId>
+					<artifactId>mockito-junit-jupiter</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-samples/spring-boot-sample-junit-vintage/src/main/java/sample/MessageController.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package sample;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class MessageController {
+
+	@GetMapping("/hi")
+	public String hello() {
+		return "Hello World";
+	}
+
+}

spring-boot-samples/spring-boot-sample-junit-vintage/src/main/java/sample/SampleJunitVintageApplication.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package sample;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SampleJunitVintageApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(SampleJunitVintageApplication.class, args);
+	}
+
+}

spring-boot-samples/spring-boot-sample-junit-vintage/src/test/java/sample/SampleJunitVintageApplicationTests.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package sample;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+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.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+public class SampleJunitVintageApplicationTests {
+
+	@Autowired
+	private TestRestTemplate restTemplate;
+
+	@Test
+	public void testMessage() {
+		String message = this.restTemplate.getForObject("/hi", String.class);
+		assertThat(message).isEqualTo("Hello World");
+	}
+
+}

src/checkstyle/checkstyle-suppressions.xml

@@ -44,4 +44,5 @@
 	<suppress files="JavaLoggingSystemTests" checks="SpringJUnit5" />
 	<suppress files="Log4J2LoggingSystemTests" checks="SpringJUnit5" />
 	<suppress files="RestClientTestWithComponentIntegrationTests" checks="SpringJUnit5" />
+	<suppress files="SampleJunitVintageApplicationTests" checks="SpringJUnit5" />
 </suppressions>