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

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);
	
	@Autowired
	private SupplyDemandService supplyDemandService;
	@Autowired
	private 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);
	}
	
	@Override
	public 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);
		}
		
	}
}