SpringRunner tutorial
last modified October 18, 2023
SpringRunner tutorial shows how to test Spring applications with SpringRunner.
Spring is a popular Java application framework. In the tutorial, we use Spring 5 version.
SpringRunner
SpringRunner
is an alias for the SpringJUnit4ClassRunner
, which
joins JUnit
testing library with the Spring TestContext Framework.
We use it with @RunWith(SpringRunner.class)
.
With SpringRunner
, we can implement standard JUnit 4-based unit and integration tests.
The Spring TestContext Framework provides generic, annotation-driven unit and integration testing support that is agnostic of the testing framework in use (JUnit, TestNG).
SpringRunner example
In the following application we test a simple service with SprigRunner
.
The application is a Spring standalone console application.
The application contains two property files: one file is for the production application, the other one for testing.
pom.xml src ├───main │ ├───java │ │ └───com │ │ └───zetcode │ │ │ Application.java │ │ ├───config │ │ │ AppConfig.java │ │ └───service │ │ HelloService.java │ └───resources │ application.properties │ logback.xml └───test ├───java │ └───com │ └───zetcode │ └───service │ HelloServiceTest.java └───resources appTest.properties
This is the project structure.
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.zetcode</groupId> <artifactId>springrunnerex</artifactId> <version>1.0-SNAPSHOT</version> <packaging>jar</packaging> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>17</maven.compiler.source> <maven.compiler.target>17</maven.compiler.target> <spring-version>5.3.23</spring-version> </properties> <dependencies> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.4.0</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.hamcrest</groupId> <artifactId>hamcrest-all</artifactId> <version>1.3</version> <scope>test</scope> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>exec-maven-plugin</artifactId> <version>3.1.0</version> <configuration> <mainClass>com.zetcode.Application</mainClass> </configuration> </plugin> </plugins> </build> </project>
This is the Maven build file. We have the following dependencies: logback-classic
for logging, spring-context
and spring-core
are basic Spring
dependencies, spring-test
is for testing, hamcrest-all
contains
all modules for the Hamcrest matching library, and JUnit
is the library
for unit testing.
The exec-maven-plugin
helps execute system and Java programs.
<?xml version="1.0" encoding="UTF-8"?> <configuration> <logger name="org.springframework" level="ERROR"/> <logger name="com.zetcode" level="INFO"/> <appender name="consoleAppender" class="ch.qos.logback.core.ConsoleAppender"> <encoder> <Pattern>%d{HH:mm:ss.SSS} %blue(%-5level) %magenta(%logger{36}) - %msg %n </Pattern> </encoder> </appender> <root> <level value="INFO" /> <appender-ref ref="consoleAppender" /> </root> </configuration>
The logback.xml
is a configuration file for the Logback logging library.
app.message=Hello there!
The application.properties
contains one message property, which is
displayed by the HelloMessage
service.
package com.zetcode.config; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.PropertySource; @Configuration @ComponentScan(basePackages = "com.zetcode") @PropertySource("application.properties") public class AppConfig { }
AppConfig
configures component scanning and loads properties from
the provided file.
package com.zetcode.service; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Service; @Service public class HelloService { @Value("${app.message}") private String message; public String sayHello() { return message; } }
HelloService
returns a message retrieved from the application.properties
file.
package com.zetcode; import com.zetcode.config.AppConfig; import com.zetcode.service.HelloService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import org.springframework.stereotype.Component; @Component public class Application { private static final Logger logger = LoggerFactory.getLogger(Application.class); public static void main(String[] args) { var ctx = new AnnotationConfigApplicationContext(AppConfig.class); var app = ctx.getBean(Application.class); app.run(); ctx.close(); } @Autowired private HelloService helloService; private void run() { logger.info("Calling hello service"); logger.info(helloService.sayHello()); } }
The application prints a message to the console using HelloService
.
$ mvn -q exec:java 17:50:54.118 INFO com.zetcode.Application - Calling hello service 17:50:54.118 INFO com.zetcode.Application - Hello there!
We run the application.
app.message=Testing hello message
The appTest.properties
is specific for the testing.
package com.zetcode.service; import com.zetcode.config.AppConfig; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.TestPropertySource; import org.springframework.test.context.junit4.SpringRunner; import static org.hamcrest.CoreMatchers.equalTo; import static org.junit.Assert.assertThat; @RunWith(SpringRunner.class) @ContextConfiguration(classes={HelloService.class}) @TestPropertySource("/appTest.properties") public class HelloServiceTest { @Value("${app.message}") private String message; @Autowired private HelloService helloService; @Test public void testHelloMessage() { var message = helloService.sayHello(); assertThat(message, equalTo(message)); } }
HelloServiceTest
is used for testing the HelloService
class.
@RunWith(SpringRunner.class) @ContextConfiguration(classes={HelloService.class}) @TestPropertySource("/appTest.properties") public class HelloServiceTest {
The test class is annotated with @RunWith(SpringRunner.class)
.
The @ContextConfiguration
defines class-level metadata which is used to
determine how to load and configure an application context for integration tests.
In addition, we provide custom test property file with @TestPropertySource
.
@Value("${app.message}") private String message;
We inject the message from the appTest.properties
file.
@Autowired private HelloService helloService;
We inject the HelloMessage
service class. This is the class to
be tested.
@Test public void testHelloMessage() { var message = helloService.sayHello(); assertThat(message, equalTo(message)); }
We test that the message from the service method equals to the injected string value.
$ mvn -q test ------------------------------------------------------- T E S T S ------------------------------------------------------- Running com.zetcode.service.HelloServiceTest Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.489 sec Results : Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
We run the tests.
In this article we shown how to use SpringRunner
to create tests
in a Spring application.
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