== 单元测试应用示例——测试Servlet类 == 
Servlet对象由Web容器创建,它依赖HttpServletRequest,HttpServletResponse,ServletConfig等对象,很难使用Junit进行单元测试.但如果借助Spring测试框架的话，就比较容易了.[[BR]]
Spring测试框架提供了MockHttpServletRequest，MockHttpServletResponse，MockServletConfig，等对象，可以很方便地模拟Servlet依赖的环境。[[BR]]

AdRegistedServlet在用户在游戏的注册引导页完成注册后，将用户信息统计到数据库.[[BR]]
{{{ #!java
/**
 * 
 * @author ChenYang
 * Date: 2011-12-30
 */
public class AdRegistedServlet extends HttpServlet {
	
	private static Log log = LogFactory.getLog(AdRegistedServlet.class);
	
	
	private ApplicationContext applicationContext = null;

	public void setApplicationContext(ApplicationContext applicationContext) {
		this.applicationContext = applicationContext;
	}

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {
		doPost(req,res);
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse res)
			throws ServletException, IOException {
		
		String accountId = req.getParameter("accountId");
		
		String returnUrl = req.getParameter("return");
		
		if(StringUtils.isBlank(accountId)){
			return;
		}
		
		Passport passport = (Passport) applicationContext.getBean("passport");
		try {
			Session realmSession = passport.login(req, res);
			log.info(realmSession.getAccountId());
		} catch (LoginException e) {
			log.error(e.getMessage());
		}
		
		String srcid = req.getParameter("srcid");
		
		if(StringUtils.isBlank(srcid)){
			res.sendRedirect(returnUrl);
		}else{
			
			AdTypeDAO adTypeDAO = (AdTypeDAO) applicationContext.getBean("adTypeDAO");
			AdType adType = adTypeDAO.find(Long.valueOf(srcid));
			
			if(adType == null){
				log.info("非法的推广来源："+srcid);
				res.sendRedirect(returnUrl);
				return;
			}
			
			String ip = IpUtils.getIp(req);
			AdRequest ad_request = new AdRequest();
			ad_request.setSrcId(StringUtils.isBlank(srcid) ? -1 : Long.valueOf(srcid));
			ad_request.setSrc(adType == null ? "" : adType.getSrc());
			
			ad_request.setIp(ip);
			
			String referer = req.getHeader("Referer");
			
			if(referer == null){
				return;
			}
		
			long gameid = AdRequestUtils.refererToGameId(referer);
			
			if(gameid == 0){
				log.info("未配置游戏id的请求来源："+referer);
				res.sendRedirect(returnUrl);
				return;
			}
			
			ad_request.setGameid(gameid);
			
			ad_request.setUserid(Long.valueOf(accountId));
			Date now = new Date();
			ad_request.setCreateAt(now);
			ad_request.setStatus(AdRequestUtils.REGISTED_STATUS);
			ad_request.setReferer(req.getParameter("referer"));
		
			AdRequestDAO adRequestDAO = (AdRequestDAO) applicationContext.getBean("adRequestDAO");
			adRequestDAO.createAdRequest(ad_request);
			res.sendRedirect(returnUrl);
		}
		
	}

	@Override
	public void init(ServletConfig config) throws ServletException {
		if(applicationContext == null){
			ServletContext ctx = config.getServletContext();
			this.applicationContext = WebApplicationContextUtils.getWebApplicationContext(ctx);
		}
	}
	
	
	
}
}}}

要测试doPost()方法的话，首先要准备applicationContext,我们可以通过继承AbstractTransactionalJUnit4SpringContextTests,以获得ApplicationContext[[BR]]
然后，我们要模拟HttpServletRequest,HttpServletResponse
{{{ #!java
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:applicationContext.xml" })
public class AdRegistedServletTest extends AbstractTransactionalJUnit4SpringContextTests{
	
	@Before
	public void init(){
		 Env env = EnvUtils.getEnv();
		 MockHttpServletRequest request = new MockHttpServletRequest();
		 request.addHeader("X-Forwarded-For", "192.168.20.92");
		 request.addHeader("X-Real-IP", "192.168.20.92");
		 request.setRemoteAddr("192.168.20.92");
		 
		 env.setRequest(request);
	}
	
	@After
	public void destory(){
		EnvUtils.removeEnv();
	}
	
	@Autowired
    CacheClient cacheClient;
	
	@Autowired
	private AdTypeDAO adTypeDAO;
	
	/**
	 * 测试正常流程
	 * @throws Exception
	 */
	@Test
	public void doPost() throws Exception {
		
		final AdRegistedServlet adRegistedServlet = new AdRegistedServlet();
		adRegistedServlet.setApplicationContext(applicationContext);

                //模拟ServletConfig
		MockServletConfig config = new MockServletConfig();
		adRegistedServlet.init(config);
		
                //模拟HttpServletRequest
		final MockHttpServletRequest request = new MockHttpServletRequest();
		request.addHeader("Referer", "http://g2.pcgames.com.cn/popularize/sxd_register.jsp");
		request.addHeader("X-Forwarded-For", "192.168.20.92");
		request.addHeader("X-Real-IP", "192.168.20.92");
		request.setRemoteAddr("192.168.20.92");
		
		AdType adType = new AdType();
		adType.setSrc("wltg");
		
		long srcid = adTypeDAO.create(adType);
		
		request.addParameter("srcid", ""+srcid);
		request.addParameter("accountId", "393648562");
		request.addParameter("referer", "http://www.sina.com.cn");
		request.addParameter("return", "http://g2.pcgames.com.cn");
		
                //模拟HttpServletResponse
		final MockHttpServletResponse response = new MockHttpServletResponse();
		
		Mockery ctx = new Mockery();
		final EnvInterface env = ctx.mock(EnvInterface.class);
		request.setAttribute("env", env);
		
		ctx.checking(new Expectations(){
			{
				one(env).getRoot();
				will(returnValue("http://g2.pcgames.com.cn"));
			}
		});
		
		adRegistedServlet.doPost(request, response);
		
		AdRequestDAO adRequestDAO = (AdRequestDAO) applicationContext.getBean("adRequestDAO");
		List<AdRequest> list = adRequestDAO.query("SELECT * FROM ad_request WHERE userid = 393648562 AND ip = '192.168.20.92' AND srcid = "+srcid);
                
                //断言doPost()后，与我们期望的结果一致
		Assert.assertEquals(1,list.size());
		
	}
 ..................

}

}}}