java基于ssh考试题

package com.tellhow.filter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.context.WebApplicationContext; import org.springframework.web.context.support.WebApplicationContextUtils; import com.tellhow.bean.UserBean; import com.tellhow.dao.UserDao; import com.tellhow.dao.UserDaoImpl; /** * Servlet Filter implementation class LoginFilter */ public class LoginFilter implements Filter { private WebApplicationContext wac = null; private UserDaoImpl userDao = null; /** * Default constructor. */ public LoginFilter() { // TODO Auto-generated constructor stub } /** * @see Filter#destroy() */ public void destroy() { // TODO Auto-generated method stub } /** * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain) */ public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // TODO Auto-generated method stub // place your code here // pass the request along the filter chain userDao = (UserDaoImpl)wac.getBean("userDao"); HttpServletRequest req = (HttpServletRequest) request; HttpServletResponse res = (HttpServletResponse)response; String url = req.getRequestURL().toString(); String username = req.getParameter("username"); String password = req.getParameter("password"); UserBean user = new UserBean(); user.setUsername(username); user.setPassword(password); if(url.indexOf("login.jsp") > 0){ chain.doFilter(req, res); return; } if(req.getSession().getAttribute("user") == null){ user.setUsername(username); user.setPassword(password); if(userDao.findAllUser(user) == 0){ res.sendRedirect("login.jsp"); } else{ req.getSession().setAttribute("user", user); res.sendRedirect("addShopping.jsp"); } } else{ chain.doFilter(req, res); } } /** * @see Filter#init(FilterConfig) */ public void init(FilterConfig fConfig) throws ServletException { // TODO Auto-generated method stub ServletContext application = fConfig.getServletContext(); wac = WebApplicationContextUtils.getWebApplicationContext(application); } }