一个和spring整合的依赖注入的servlet，子类可自动装配依赖Bean

工作中，有时候可能会直接使用到servlet，这样，和spring整合起来，就有点麻烦，还要写个spring的代理，比较麻烦，下面这个servlet，就不需要了。如果继承了这个servlet，那么，他的子类就会具有自动装配的功能了。代码如下：

import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.beans.factory.config.AutowireCapableBeanFactory;import org.springframework.web.context.WebApplicationContext;import org.springframework.web.context.support.WebApplicationContextUtils;public abstract class AutowiredHttpServlet extends HttpServlet {private static final long serialVersionUID = -2000909174467653847L;public void init() throws ServletException {super.init();WebApplicationContext ctx = WebApplicationContextUtils.getWebApplicationContext(getServletContext());AutowireCapableBeanFactory factory = ctx.getAutowireCapableBeanFactory();factory.autowireBean(this);}public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{servlet(request, response);}public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{servlet(request, response);}/** * 子类实现该方法，进行Servlet Post和Get请求服务。 * @param request HttpServletRequest实例 * @param response HttpServletResponse实例 * @throws IOException * @throws ServletException * @author yinlei * date 2011-8-9 下午7:15:41 */public abstract void servlet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException;/** * 直接输出json。 */public void renderJson(HttpServletResponse response, String json) {response(response, json, "application/json;charset=UTF-8");}/** * 直接输出纯HTML。 */public void renderHtml(HttpServletResponse response, String text) {response(response, text, "text/html;charset=UTF-8");}/** * 直接输出纯字符串。 */public void renderText(HttpServletResponse response, String text) {response(response, text, "text/plain;charset=UTF-8");}public void response(HttpServletResponse response, String text, String contentType) {try {response.setContentType(contentType);response.getWriter().write(text);} catch (IOException e) {}}}

这样以来，他的子类，可以直接像struts2和spring mvc一样，直接将service bean都注入进来了。例如：

public class DemandServlet extends AutowiredHttpServlet {private static final long serialVersionUID = 1L;private static final Logger logger = LoggerFactory.getLogger(DemandServlet.class);@Autowiredprivate SupplyDemandService supplyDemandService;@Autowiredprivate UserMemberService userMemberService;public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {servlet(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {servlet(request, response);}@Overridepublic void servlet(HttpServletRequest request, HttpServletResponse response)throws IOException, ServletException {String type = request.getParameter("type");String userId = request.getParameter("userId");if (type == null || type.equals("init")) {// 去发布，需要验证用户的信息//去发布求购，验证用户信息是否完整Member member = userMemberService.get(userId);if (member == null || member.getSopenid() == null) {// 验证没有通过，让用户完善信息request.getRequestDispatcher("weixin/binding.jsp").forward(request, response);} else {// 已经验证通过，跳转到发布页面request.getRequestDispatcher("weixin/demand.jsp").forward(request, response);}} else if (type.equals("publish")) {// 发布//绑定数据SupplyDemandInf demand = binder(request);supplyDemandService.saveOrUpdate(demand);request.getRequestDispatcher("weixin/demandPublishSuccess.jsp").forward(request, response);}}}