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.

pom.xml

<?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.

resources/logback.xml

<?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.

resources/application.properties

app.message=Hello there!

The application.properties contains one message property, which is displayed by the HelloMessage service.

com/zetcode/AppConfig.java

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.

com/zetcode/servide/HelloService.java

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.

com/zetcode/Application.java

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.

resources/appTest.properties

app.message=Testing hello message

The appTest.properties is specific for the testing.

com/zetcode/service/HelloServiceTest.java

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.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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