Spring has a
nice framework to unit test controller for web/rest applications and it integrates nicely with Junit.Assuming that you wrote a CustomerController for handling REST requests to create a customer. A basic CustomerController looks like this:
@Controller
@RequestMapping("/customers")
public class CustomerController {
@RequestMapping (method = RequestMethod.POST)
public void createCustomer(HttpServletRequest request,
HttpServletResponse response) {
//your code here
}
}
Now to test this controller using Spring Mock objects, the basic steps are as follows in your unit test:
Step1: Declare that you want to run test using JUnit. For example to run test using JUnit4 you need to use
@RunWith annotation as follows:
@RunWith(SpringJUnit4ClassRunner.class)
public class CustomerControllerTest extends TestCase {
@Test
public void testCreateCustomer() throws Exception {
}
}
Specify the spring bean configuration using
@ContextConfiguration so that Controller works from unit test.
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring/customer/rest-config.xml")
public class CustomerControllerTest extends TestCase {
@Test
public void testCreateCustomer() throws Exception {
}
}
Setup
DispatcherServlet. DispatchServlet will be used to send mock request to the controller. Setting up DispatchServlet requires implementing
ApplicationContextAware.
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring/customer/rest-config.xml")
public class CustomerControllerTest extends TestCase implements ApplicationContextAware {
private Servlet servlet;
private ApplicationContext applicationContext;
@SuppressWarnings("serial")
@Before
private void init() {
servlet = new DispatcherServlet() {
@Override
protected WebApplicationContext createWebApplicationContext(
WebApplicationContext parent) throws BeansException {
GenericWebApplicationContext genericContext = new GenericWebApplicationContext();
genericContext.setParent(applicationContext);
genericContext.refresh();
return genericContext;
}
};
}
@Test
public void testCreateCustomer() throws Exception {
}
public void setApplicationContext(ApplicationContext arg0)
throws BeansException {
this.applicationContext = arg0;
}
}
Finally use
MockHttpServletRequest to build the request, send it and process the response.
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring/customer/rest-config.xml")
public class CustomerControllerTest extends TestCase implements ApplicationContextAware {
private Servlet servlet;
private ApplicationContext applicationContext;
@SuppressWarnings("serial")
@Before
private void init() {
servlet = new DispatcherServlet() {
@Override
protected WebApplicationContext createWebApplicationContext(
WebApplicationContext parent) throws BeansException {
GenericWebApplicationContext genericContext = new GenericWebApplicationContext();
genericContext.setParent(applicationContext);
genericContext.refresh();
return genericContext;
}
};
}
@Test
public void testCreateCustomer() throws Exception {
MockHttpServletRequest request = new MockHttpServletRequest();
// set uri, request parameter, request body, omitted here
MockHttpServletResponse response = new MockHttpServletResponse();
// send the request
MockServletConfig servletConfig = new MockServletConfig();
servlet.init(servletConfig);
servlet.service(request, response);
// validate response
String responseContent = response.getContentAsString();
int responseCode = response.getStatus();
}
public void setApplicationContext(ApplicationContext arg0)
throws BeansException {
this.applicationContext = arg0;
}
}
