Spring MockMvc tutorial
last modified October 18, 2023
Spring MockMvc tutorial shows how to test Spring MVC application with MockMvc.
Spring is a popular Java application framework for creating enterprise applications.
MockMvc
MockMvc is defined as a main entry point for server-side Spring MVC testing.
Tests with MockMvc lie somewhere between between unit and integration tests.
Spring MockMvc example
The following application uses MockMvc to test a Spring MVC application.
We create a test for a template and for a RESTful controller method.
pom.xml
src
├───main
│ ├───java
│ │ └───com
│ │ └───zetcode
│ │ ├───config
│ │ │ MyWebInitializer.java
│ │ │ WebConfig.java
│ │ └───controller
│ │ MyController.java
│ ├───resources
│ └───webapp
│ └───WEB-INF
│ └───templates
│ index.html
└───test
└───java
└───com
└───zetcode
└───controller
MyControllerTest.java
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>mockmvcex</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</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>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring-version}</version>
</dependency>
<dependency>
<groupId>org.thymeleaf</groupId>
<artifactId>thymeleaf-spring5</artifactId>
<version>3.0.11.RELEASE</version>
</dependency>
<dependency>
<groupId>org.thymeleaf</groupId>
<artifactId>thymeleaf</artifactId>
<version>3.0.11.RELEASE</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.2</version>
</plugin>
</plugins>
</build>
</project>
In the pom.xml file we have the following dependencies: logback-classic,
javax.servlet-api, junit, spring-webmvc,
spring-test, thymeleaf-spring5 and thymeleaf.
package com.zetcode.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
@Configuration
public class MyWebInitializer extends
AbstractAnnotationConfigDispatcherServletInitializer {
@Override
protected Class<?>[] getRootConfigClasses() {
return null;
}
@Override
protected Class<?>[] getServletConfigClasses() {
return new Class[]{WebConfig.class};
}
@Override
protected String[] getServletMappings() {
return new String[]{"/"};
}
}
MyWebInitializer registers the Spring DispatcherServlet, which
is a front controller for a Spring web application.
@Override
protected Class<?>[] getServletConfigClasses() {
return new Class[]{WebConfig.class};
}
The getServletConfigClasses returns a web configuration class.
package com.zetcode.config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.thymeleaf.spring5.SpringTemplateEngine;
import org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver;
import org.thymeleaf.spring5.view.ThymeleafViewResolver;
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"com.zetcode"})
public class WebConfig {
@Autowired
private ApplicationContext applicationContext;
@Bean
public SpringResourceTemplateResolver templateResolver() {
var templateResolver = new SpringResourceTemplateResolver();
templateResolver.setApplicationContext(applicationContext);
templateResolver.setPrefix("/WEB-INF/templates/");
templateResolver.setSuffix(".html");
return templateResolver;
}
@Bean
public SpringTemplateEngine templateEngine() {
var templateEngine = new SpringTemplateEngine();
templateEngine.setTemplateResolver(templateResolver());
templateEngine.setEnableSpringELCompiler(true);
return templateEngine;
}
@Bean
public ViewResolver viewResolver() {
var resolver = new ThymeleafViewResolver();
var registry = new ViewResolverRegistry(null, applicationContext);
resolver.setTemplateEngine(templateEngine());
registry.viewResolver(resolver);
return resolver;
}
}
The WebConfig enables Spring MVC annotations with @EnableWebMvc
and configures component scanning for the com.zetcode package. It sets up
the Thymeleaf engine.
package com.zetcode.controller;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.time.LocalDateTime;
@Controller
public class MyController {
@GetMapping(value = "/", produces = MediaType.TEXT_HTML_VALUE)
public String home(Model model) {
model.addAttribute("now", LocalDateTime.now());
return "index";
}
@GetMapping(value = "/message", produces = MediaType.TEXT_PLAIN_VALUE)
@ResponseBody
public String message() {
return "Hello there!";
}
}
MyController provides two handler methods. The home method
return a view with a single attribute and the message method returns
a plain text message. In our tests we test these two methods.
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Home page</title>
</head>
<body>
<p>
Today is: <span th:text="${now}"></span>
</p>
</body>
</html>
This is the index.html view.
package com.zetcode.controller;
import org.junit.Before;
import org.junit.Test;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.view;
public class MyControllerTest {
private MockMvc mockMvc;
@Before
public void setup() {
this.mockMvc = MockMvcBuilders.standaloneSetup(new MyController()).build();
}
@Test
public void testHomePage() throws Exception {
this.mockMvc.perform(get("/"))
.andExpect(status().isOk())
.andExpect(view().name("index"))
.andDo(MockMvcResultHandlers.print())
.andReturn();
}
@Test
public void testMessagePage() throws Exception {
this.mockMvc.perform(get("/message")).andExpect(status().isOk())
.andExpect(content().string("Hello there!"));
}
}
MyControllerTest tests the two handlers.
private MockMvc mockMvc;
@Before
public void setup() {
this.mockMvc = MockMvcBuilders.standaloneSetup(new MyController()).build();
}
We set up the MockMvc. We add the MyController to the
standalone setup. The MockMvcBuilders.standaloneSetup allows to register
one or more controllers without the need to use the full WebApplicationContext.
@Test
public void testHomePage() throws Exception {
this.mockMvc.perform(get("/"))
.andExpect(status().isOk())
.andExpect(view().name("index"))
.andDo(MockMvcResultHandlers.print());
}
We test the home page. We verify the status and the returned view name. We also print the result.
@Test
public void testMessagePage() throws Exception {
this.mockMvc.perform(get("/message")).andExpect(status().isOk())
.andExpect(content().string("Hello there!"));
}
We test the message page. Since it is a RESTful method, we verify the status and the returned string.
$ mvn -q test
We run the tests with mvn -q test.
In this article we have created tests for Spring MVC with MockMvc.
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