JavaWeb程序填空题知识点总结

Servlet

extends HttpServlet HttpServletRequest HttpServletResponse throws ServletException, IOException web.xml中的配置信息

ServletContext

获取：getServletContext(); 保存：context.setAttribute("times", times)

ServletConfig-获取servlet的配置信息

获取：ServletConfig config = this.getServletConfig() 获取参数名所对应的参数值：String param = config.getInitParameter("参数名")

response

设置编码： resp.setContentType("text/html;charset=GB2312"); resp.setContentType("text/html;charset=utf-8"); 得到输出流对象： PrintWriter out = resp.getWriter(); out.println("XXX"); 禁止浏览器缓存： resp.setDateHeader("Expires", 0); resp.setHeader("Cache-Control", "no-cache"); resp.setHeader("Pragma", "no-cache"); 实现重定向： response.sendRedirect(request.getContextPath() + "/index.jsp");

request

Cookie

获取所有的cookie Cookie[] cookies = request.getCookies(); 获取第i个cookie的键和值 cookies[i].getName(); cookies[i].getValue(); 创建cookie // 创建cookie Cookie cookie = new Cookie(键, 值); // 设置保存时间 cookie.setMaxAge(60 * 60); // 设置路径：访问chapter05下资源时回送cookie cookie.setPath("/chapter05"); // 发送cookie response.addCookie(cookie);

Session

创建或者获得用户的Session对象 HttpSession session = req.getSession(); 获取属性对应的值 session.getAttribute("cart"); 设置session session.setAttribute("cart", cart); 创建cookie存放Session的标识号 Cookie cookie = new Cookie("JSESSIONID", session.getId()); cookie.setMaxAge(60 * 30); cookie.setPath("/chapter05"); resp.addCookie(cookie);

Filter

编写web.xml文件，设置对MyServlet的拦截

Listener

编写一个MyAttributeListener类，该类实现了ServletContextAttributeListener、HttpSessionAttributeListener和ServletRequestAttributeListener接口，并实现该接口中的所有方法 public class MyAttributeListener implements ServletContextAttributeListener, HttpSessionAttributeListener, ServletRequestAttributeListener { public void attributeAdded(ServletContextAttributeEvent sae) { String name = sae.getName(); System.out.println("ServletContext添加属性：" + name + "=" + sae.getServletContext().getAttribute(name)); } public void attributeRemoved(ServletContextAttributeEvent sae) { String name = sae.getName(); System.out.println("ServletContext移除属性: " + name); } public void attributeReplaced(ServletContextAttributeEvent sae) { String name = sae.getName(); System.out.println("ServletContext替换属性：" + name + "=" + sae.getServletContext().getAttribute(name)); } public void attributeAdded(HttpSessionBindingEvent hbe) { String name = hbe.getName(); System.out.println("HttpSession添加属性：" + name + "=" + hbe.getSession().getAttribute(name)); } public void attributeRemoved(HttpSessionBindingEvent hbe) { String name = hbe.getName(); System.out.println("HttpSession移除属性: " + name); } public void attributeReplaced(HttpSessionBindingEvent hbe) { String name = hbe.getName(); System.out.println("HttpSession替换属性：" + name + "=" + hbe.getSession().getAttribute(name)); } public void attributeAdded(ServletRequestAttributeEvent sra) { String name = sra.getName(); System.out.println("ServletRequest添加属性：" + name + "=" + sra.getServletRequest().getAttribute(name)); } public void attributeRemoved(ServletRequestAttributeEvent sra) { String name = sra.getName(); System.out.println("ServletRequest移除属性: " + name); } public void attributeReplaced(ServletRequestAttributeEvent sra) { String name = sra.getName(); System.out.println("ServletRequest替换属性：" + name + "=" + sra.getServletRequest().getAttribute(name)); } } 在web.xml文件中，部署MyAttributeListener事件监听器

数据库

请编写一个用于读取数据库中users表信息的JDBC程序，要求分别获取字段id、name、password和email字段的值