Writing unit tests for Spring MVC controllers has traditionally been both simple and problematic. Although it is pretty simple to write unit tests which invoke controller methods, the problem is that those unit tests are not comprehensive enough. For example, we cannot test controller mappings, validation and exception handling just by invoking the tested controller method.<\/p>\n
Spring MVC Test<\/a> solved this problem by giving us the possibility to invoke controller methods through the DispatcherServlet<\/em>. This is the first part of my tutorial which describes the unit testing of Spring MVC controllers and it describes how we can configure our unit tests. Let\u2019s get started.<\/p>\n We can get the required dependencies by declaring the following testing dependencies in our pom.xml<\/em> file:<\/p>\n The relevant part of our pom.xml<\/em> file looks as follows:<\/p>\n Let\u2019s move on and take a quick look at our example application.<\/p>\n The example application of this tutorial provides CRUD operations for todo entries. In order to understand the configuration of our test class, we must have some knowledge about the tested controller class.<\/p>\n At this point, we need to know the answers to these questions:<\/p>\n We can get the answers to those questions by taking a look at the source code of the TodoController<\/em> class. The relevant part of the TodoController<\/em> class looks as follows:<\/p>\n As we can see, our controller class has two dependencies: TodoService<\/em> and MessageSource<\/em>. Also, we can see that our controller class uses constructor injection.<\/p>\n At this point this is all there information we need. Next we will talk about our application context configuration.<\/p>\n Maintaining a separate application context configurations for our application and our tests is cumbersome. Also, It can lead into problems if we change something in the application context configuration of our application but forget to do the same change for our test context.<\/p>\n That is why the application context configuration of the example application has been divided in a such way that we can reuse parts of it in our tests.<\/p>\n Our application context configuration has been divided as follows:<\/p>\n Note:<\/strong> The example application has also a working application context configuration which uses XML configuration files. The XML configuration files which correspond with the Java configuration classes are: exampleApplicationContext.xml<\/em>, exampleApplicationContext-web.xml and exampleApplicationContext-persistence.xml<\/em>.<\/p>\n Let\u2019s take a look at the application context configuration of our web layer and find out how we can configure our test context.<\/p>\n The application context configuration of the web layer has the following responsibilities:<\/p>\n Let\u2019s move on and take a look at the Java configuration class and the XML configuration file.<\/p>\n If we use Java configuration, the source code of the WebAppContext<\/em> class looks as follows:<\/p>\n If we use XML configuration, the content of the exampleApplicationContext-web.xml<\/em> file looks as follows: The configuration of our test context has two responsibilities:<\/p>\n Let\u2019s find out how we configure our test context by using Java configuration class and XML configuration file.<\/p>\n If we configure our test context by using Java configuration, the source code of the TestContext<\/em> class looks as follows:<\/p>\n If we configure our test context by using an XML configuration, the content of the testContext.xml<\/em> file looks as follow:<\/p>\n We can configure our test class by using one of the following options:<\/p>\n Let\u2019s move on and find out how we can configure our test class by using both configuration options.<\/p>\n We can configure our test class by following these steps:<\/p>\n The source code of our test class looks as follows:<\/p>\n Using the standalone configuration has two problems:<\/p>\n We can configure our test class by following these steps:<\/p>\n The source code of our test class looks as follows:<\/p>\n The configuration of our test class looks a lot cleaner than the configuration which uses standalone configuration. However, the \u201cdownside\u201d is that our test uses the full Spring MVC infrastructure. This might be an overkill if our test class really uses only a few components.<\/p>\n We have now configured our unit test class by using both the standalone setup and the WebApplicationContext<\/em> based setup. This blog post has taught us two things:<\/p>\n The next part of this tutorial describes how we can write unit tests for \u201cnormal\u201d Spring MVC controllers.<\/p>\n P.S. The example application of this blog post is available at Github<\/a>. Writing unit tests for Spring MVC controllers has traditionally been both simple and problematic. Although it is pretty simple to write unit tests which invoke controller methods, the problem is that those unit tests are not comprehensive enough. For example, we cannot test controller mappings, validation and exception handling just by invoking the tested controller …<\/p>\n","protected":false},"author":429,"featured_media":240,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[30,150],"class_list":["post-15087","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-enterprise-java","tag-spring","tag-spring-mvc"],"yoast_head":"\nGetting the Required Dependencies with Maven<\/h2>\n
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<dependency>\r\n <groupId>junit<\/groupId>\r\n <artifactId>junit<\/artifactId>\r\n <version>4.11<\/version>\r\n <scope>test<\/scope>\r\n<\/dependency>\r\n<dependency>\r\n <groupId>org.mockito<\/groupId>\r\n <artifactId>mockito-core<\/artifactId>\r\n <version>1.9.5<\/version>\r\n <scope>test<\/scope>\r\n<\/dependency>\r\n<dependency>\r\n <groupId>org.springframework<\/groupId>\r\n <artifactId>spring-test<\/artifactId>\r\n <version>3.2.3.RELEASE<\/version>\r\n <scope>test<\/scope>\r\n<\/dependency><\/pre>\n
The Anatomy of Our Example Application<\/h2>\n
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import org.springframework.beans.factory.annotation.Autowired;\r\nimport org.springframework.context.MessageSource;\r\nimport org.springframework.stereotype.Controller;\r\n\r\n@Controller\r\npublic class TodoController {\r\n\r\n private final TodoService service;\r\n\r\n private final MessageSource messageSource;\r\n\r\n @Autowired\r\n public TodoController(MessageSource messageSource, TodoService service) {\r\n this.messageSource = messageSource;\r\n this.service = service;\r\n }\r\n\r\n \/\/Other methods are omitted.\r\n}<\/pre>\nConfiguring the Application Context<\/h2>\n
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Configuring the Web Layer<\/h3>\n
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Java Configuration<\/h2>\n
import org.springframework.context.annotation.Bean;\r\nimport org.springframework.context.annotation.ComponentScan;\r\nimport org.springframework.context.annotation.Configuration;\r\nimport org.springframework.web.servlet.ViewResolver;\r\nimport org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;\r\nimport org.springframework.web.servlet.config.annotation.EnableWebMvc;\r\nimport org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;\r\nimport org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;\r\nimport org.springframework.web.servlet.handler.SimpleMappingExceptionResolver;\r\nimport org.springframework.web.servlet.view.InternalResourceViewResolver;\r\nimport org.springframework.web.servlet.view.JstlView;\r\n\r\nimport java.util.Properties;\r\n\r\n@Configuration\r\n@EnableWebMvc\r\n@ComponentScan(basePackages = {\r\n \"net.petrikainulainen.spring.testmvc.common.controller\",\r\n \"net.petrikainulainen.spring.testmvc.todo.controller\"\r\n})\r\npublic class WebAppContext extends WebMvcConfigurerAdapter {\r\n\r\n @Override\r\n public void addResourceHandlers(ResourceHandlerRegistry registry) {\r\n registry.addResourceHandler(\"\/static\/**\").addResourceLocations(\"\/static\/\");\r\n }\r\n\r\n @Override\r\n public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {\r\n configurer.enable();\r\n }\r\n\r\n @Bean\r\n public SimpleMappingExceptionResolver exceptionResolver() {\r\n SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();\r\n\r\n Properties exceptionMappings = new Properties();\r\n\r\n exceptionMappings.\r\nput(\"net.petrikainulainen.spring.testmvc.todo.exception.TodoNotFoundException\", \"error\/404\");\r\n exceptionMappings.put(\"java.lang.Exception\", \"error\/error\");\r\n exceptionMappings.put(\"java.lang.RuntimeException\", \"error\/error\");\r\n\r\n exceptionResolver.setExceptionMappings(exceptionMappings);\r\n\r\n Properties statusCodes = new Properties();\r\n\r\n statusCodes.put(\"error\/404\", \"404\");\r\n statusCodes.put(\"error\/error\", \"500\");\r\n\r\n exceptionResolver.setStatusCodes(statusCodes);\r\n\r\n return exceptionResolver;\r\n }\r\n\r\n @Bean\r\n public ViewResolver viewResolver() {\r\n InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();\r\n\r\n viewResolver.setViewClass(JstlView.class);\r\n viewResolver.setPrefix(\"\/WEB-INF\/jsp\/\");\r\n viewResolver.setSuffix(\".jsp\");\r\n\r\n return viewResolver;\r\n }\r\n}<\/pre>\nXML Configuration<\/h2>\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<beans xmlns=\"http:\/\/www.springframework.org\/schema\/beans\"\r\n xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\r\n xmlns:mvc=\"http:\/\/www.springframework.org\/schema\/mvc\"\r\n xmlns:context=\"http:\/\/www.springframework.org\/schema\/context\"\r\n xsi:schemaLocation=\"http:\/\/www.springframework.org\/schema\/beans http:\/\/www.springframework.org\/schema\/beans\/spring-beans.xsd\r\n http:\/\/www.springframework.org\/schema\/mvc http:\/\/www.springframework.org\/schema\/mvc\/spring-mvc-3.1.xsd\r\n http:\/\/www.springframework.org\/schema\/context http:\/\/www.springframework.org\/schema\/context\/spring-context-3.1.xsd\">\r\n\r\n <mvc:annotation-driven\/>\r\n\r\n <mvc:resources mapping=\"\/static\/**\" location=\"\/static\/\"\/>\r\n <mvc:default-servlet-handler\/>\r\n\r\n <context:component-scan base-package=\"net.petrikainulainen.spring.testmvc.common.controller\"\/>\r\n <context:component-scan base-package=\"net.petrikainulainen.spring.testmvc.todo.controller\"\/>\r\n\r\n <bean id=\"exceptionResolver\" class=\"org.springframework.web.servlet.handler.SimpleMappingExceptionResolver\">\r\n <property name=\"exceptionMappings\">\r\n <props>\r\n <prop key=\"net.petrikainulainen.spring.testmvc.todo.exception.TodoNotFoundException\">error\/404<\/prop>\r\n <prop key=\"java.lang.Exception\">error\/error<\/prop>\r\n <prop key=\"java.lang.RuntimeException\">error\/error<\/prop>\r\n <\/props>\r\n <\/property>\r\n <property name=\"statusCodes\">\r\n <props>\r\n <prop key=\"error\/404\">404<\/prop>\r\n <prop key=\"error\/error\">500<\/prop>\r\n <\/props>\r\n <\/property>\r\n <\/bean>\r\n\r\n <bean id=\"viewResolver\" class=\"org.springframework.web.servlet.view.InternalResourceViewResolver\">\r\n <property name=\"prefix\" value=\"\/WEB-INF\/jsp\/\"\/>\r\n <property name=\"suffix\" value=\".jsp\"\/>\r\n <property name=\"viewClass\" value=\"org.springframework.web.servlet.view.JstlView\"\/>\r\n <\/bean>\r\n<\/beans><\/pre>\n
Configuring the Test Context<\/h3>\n
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Java Configuration<\/h2>\n
import org.mockito.Mockito;\r\nimport org.springframework.context.MessageSource;\r\nimport org.springframework.context.annotation.Bean;\r\nimport org.springframework.context.annotation.Configuration;\r\nimport org.springframework.context.support.ResourceBundleMessageSource;\r\n\r\n@Configuration\r\npublic class TestContext {\r\n\r\n @Bean\r\n public MessageSource messageSource() {\r\n ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();\r\n\r\n messageSource.setBasename(\"i18n\/messages\");\r\n messageSource.setUseCodeAsDefaultMessage(true);\r\n\r\n return messageSource;\r\n }\r\n\r\n @Bean\r\n public TodoService todoService() {\r\n return Mockito.mock(TodoService.class);\r\n }\r\n}<\/pre>\nXML Configuration<\/h2>\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<beans xmlns=\"http:\/\/www.springframework.org\/schema\/beans\"\r\n xmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\"\r\n xsi:schemaLocation=\"http:\/\/www.springframework.org\/schema\/beans http:\/\/www.springframework.org\/schema\/beans\/spring-beans.xsd\">\r\n\r\n <bean id=\"messageSource\" class=\"org.springframework.context.support.ResourceBundleMessageSource\">\r\n <property name=\"basename\" value=\"i18n\/messages\"\/>\r\n <property name=\"useCodeAsDefaultMessage\" value=\"true\"\/>\r\n <\/bean>\r\n\r\n <bean id=\"todoService\" name=\"todoService\" class=\"org.mockito.Mockito\" factory-method=\"mock\">\r\n <constructor-arg value=\"net.petrikainulainen.spring.testmvc.todo.service.TodoService\"\/>\r\n <\/bean>\r\n<\/beans><\/pre>\n
Configuring The Test Class<\/h2>\n
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Using Standalone Configuration<\/h3>\n
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import org.junit.Before;\r\nimport org.junit.runner.RunWith;\r\nimport org.mockito.Mock;\r\nimport org.mockito.runners.MockitoJUnitRunner;\r\nimport org.springframework.context.MessageSource;\r\nimport org.springframework.context.support.ResourceBundleMessageSource;\r\nimport org.springframework.test.web.servlet.MockMvc;\r\nimport org.springframework.test.web.servlet.setup.MockMvcBuilders;\r\nimport org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;\r\nimport org.springframework.web.servlet.HandlerExceptionResolver;\r\nimport org.springframework.web.servlet.ViewResolver;\r\nimport org.springframework.web.servlet.handler.SimpleMappingExceptionResolver;\r\nimport org.springframework.web.servlet.view.InternalResourceViewResolver;\r\nimport org.springframework.web.servlet.view.JstlView;\r\n\r\nimport java.util.Properties;\r\n\r\n@RunWith(MockitoJUnitRunner.class)\r\npublic class StandaloneTodoControllerTest {\r\n\r\n private MockMvc mockMvc;\r\n\r\n @Mock\r\n private TodoService todoServiceMock;\r\n\r\n @Before\r\n public void setUp() {\r\n mockMvc = MockMvcBuilders.standaloneSetup(new TodoController(messageSource(), todoServiceMock))\r\n .setHandlerExceptionResolvers(exceptionResolver())\r\n .setValidator(validator())\r\n .setViewResolvers(viewResolver())\r\n .build();\r\n }\r\n\r\n private HandlerExceptionResolver exceptionResolver() {\r\n SimpleMappingExceptionResolver exceptionResolver = new SimpleMappingExceptionResolver();\r\n\r\n Properties exceptionMappings = new Properties();\r\n\r\n exceptionMappings.\r\nput(\"net.petrikainulainen.spring.testmvc.todo.exception.TodoNotFoundException\", \"error\/404\");\r\n exceptionMappings.put(\"java.lang.Exception\", \"error\/error\");\r\n exceptionMappings.put(\"java.lang.RuntimeException\", \"error\/error\");\r\n\r\n exceptionResolver.setExceptionMappings(exceptionMappings);\r\n\r\n Properties statusCodes = new Properties();\r\n\r\n statusCodes.put(\"error\/404\", \"404\");\r\n statusCodes.put(\"error\/error\", \"500\");\r\n\r\n exceptionResolver.setStatusCodes(statusCodes);\r\n\r\n return exceptionResolver;\r\n }\r\n\r\n private MessageSource messageSource() {\r\n ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();\r\n\r\n messageSource.setBasename(\"i18n\/messages\");\r\n messageSource.setUseCodeAsDefaultMessage(true);\r\n\r\n return messageSource;\r\n }\r\n\r\n private LocalValidatorFactoryBean validator() {\r\n return new LocalValidatorFactoryBean();\r\n }\r\n\r\n private ViewResolver viewResolver() {\r\n InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();\r\n\r\n viewResolver.setViewClass(JstlView.class);\r\n viewResolver.setPrefix(\"\/WEB-INF\/jsp\/\");\r\n viewResolver.setSuffix(\".jsp\");\r\n\r\n return viewResolver;\r\n }\r\n}<\/pre>\n\n
Using WebApplicationContext Based Configuration<\/h3>\n
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import org.junit.Before;\r\nimport org.junit.runner.RunWith;\r\nimport org.mockito.Mockito;\r\nimport org.springframework.beans.factory.annotation.Autowired;\r\nimport org.springframework.test.context.ContextConfiguration;\r\nimport org.springframework.test.context.junit4.SpringJUnit4ClassRunner;\r\nimport org.springframework.test.context.web.WebAppConfiguration;\r\nimport org.springframework.test.web.servlet.MockMvc;\r\nimport org.springframework.test.web.servlet.setup.MockMvcBuilders;\r\nimport org.springframework.web.context.WebApplicationContext;\r\n\r\n@RunWith(SpringJUnit4ClassRunner.class)\r\n@ContextConfiguration(classes = {TestContext.class, WebAppContext.class})\r\n\/\/@ContextConfiguration(locations = {\"classpath:testContext.xml\", \"classpath:exampleApplicationContext-web.xml\"})\r\n@WebAppConfiguration\r\npublic class WebApplicationContextTodoControllerTest {\r\n\r\n private MockMvc mockMvc;\r\n\r\n @Autowired\r\n private TodoService todoServiceMock;\r\n\r\n @Autowired\r\n private WebApplicationContext webApplicationContext;\r\n\r\n @Before\r\n public void setUp() {\r\n \/\/We have to reset our mock between tests because the mock objects\r\n \/\/are managed by the Spring container. If we would not reset them,\r\n \/\/stubbing and verified behavior would \"leak\" from one test to another.\r\n Mockito.reset(todoServiceMock);\r\n\r\n mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();\r\n }\r\n}<\/pre>\nSummary<\/h2>\n
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\n <\/p>\n