jsp网站设计与实现1563

package bbs; import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.ArrayList; /** * 控制器，接受用户的请求，并调用相应的处理方法，返回结果页面 */ public class TopicServlet extends HttpServlet { public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } /** * 判断是哪种操作 * 1，topic_delete：删除贴子 * 2，topic_add：发表新贴 * 3，answer_add：回复贴子 * 4，answer_delete：删除贴子回复 * 5，topic_update：更新贴子 * 6，answer_update：更新贴子回复 * 7，topic_select：获取帖子列表 * 8，topic_view：获取一个帖子以及该帖子的回复 */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String method = request.getParameter("method"); //从request对象中获取操作类型，后面代码根据操作类型调用相应的方法进行处理 if (method == null) { return; } else if (method.equalsIgnoreCase("topic_select")) { topic_select(request, response); //获取某一讨论区的帖子列表 } else if (method.equalsIgnoreCase("topic_view")) { topic_view(request, response); //获取某一个帖子以及该帖子的回复 } else if (method.equalsIgnoreCase("topic_delete")) { topic_delete(request, response); } else if (method.equalsIgnoreCase("topic_add")) { topic_add(request, response); //创建一个新帖子 } else if (method.equalsIgnoreCase("answer_add")) { answer_add(request, response); //回复一个帖子 } else if (method.equalsIgnoreCase("answer_delete")) { answer_delete(request, response); } else if (method.equalsIgnoreCase("topic_update")) { topic_update(request, response); } else if (method.equalsIgnoreCase("answer_update")) { answer_update(request, response); } } /** * 获取讨论区列表 * 1，获取讨论区编号forum_id * 2，调用TopicHandle的select方法，获取指定讨论区的帖子列表 * 3，如果出现异常，将异常信息保存到request对象中 * 5，返回topics.jsp页面 */ private void topic_select(HttpServletRequest request, HttpServletResponse response) { boolean isSuccess = false; //处理成功与否标记 ArrayList array = null; //用来保存结果集 String forum_id = request.getParameter("forum_id"); //获取讨论区编号forum_id String start_index = request.getParameter("start_index"); //起始页编号，分页算法中要用到 if (start_index == null) { start_index = "0"; //起始页编号为空，初始化为“0”，表示第一页 } Page pageInfo = null; //分页对象 try { pageInfo = (Page) request.getAttribute("pageInfo"); //从request中获取分页对象 if (pageInfo == null) { pageInfo = new Page(); request.setAttribute("pageInfo", pageInfo); //如果分页对象为空，就创建一个新的分页对象，并保存到request中 } pageInfo.setIndex(Integer.parseInt(start_index)); //设置分页对象的起始页 pageInfo.setUrl("topicservlet?method=topic_select&forum_id=" + forum_id); //设置页面数字对应的URL链接 array = TopicHandle.select(Integer.valueOf(forum_id).intValue(), pageInfo); //调用TopicHandle的select方法获取讨论区列表 isSuccess = true; } catch (Exception es) { isSuccess = false; request.setAttribute("topic_error", es.getMessage()); es.printStackTrace(); array = new ArrayList(); } if (isSuccess) { request.removeAttribute("topic_error"); } request.setAttribute("topics", array); //将结果集保存到request对象中 String forward = "topics.jsp?forum_id=" + forum_id; forward(request, response, forward); } /** * 浏览帖子信息 * 1，获得要浏览贴子的讨论区编号forum_id以及贴子号bbs_id * 2，调用TopicHandle的viewTopic方法，获取编号为bbs_id的贴子以及该贴子的回复 * 3，返回topic_view.jsp页面 */ private void topic_view(HttpServletRequest request, HttpServletResponse response) { String forum_id = request.getParameter("forum_id"); String bbs_id = request.getParameter("bbs_id"); //从request对象中获取贴子的讨论区编号forum_id以及贴子号bbs_id String start_index = request.getParameter("start_index"); //起始页编号，分页算法中要用到 if (start_index == null) { start_index = "0"; } Page pageInfo = null; ArrayList array = null; try { pageInfo = (Page) request.getAttribute("pageInfo"); //从request中获取分页对象 if (pageInfo == null) { pageInfo = new Page(); request.setAttribute("pageInfo", pageInfo); //如果分页对象为空，就创建一个新的分页对象，并保存到request中 } pageInfo.setIndex(Integer.parseInt(start_index)); //设置分页对象的起始页 pageInfo.setUrl("topicservlet?method=topic_view&bbs_id=" + bbs_id + "&forum_id=" + forum_id); //设置页面数字对应的URL链接 int id = Integer.parseInt(bbs_id); array = TopicHandle.viewTopic(id, pageInfo); //调用业务逻辑层对象，获取帖子以及该帖子的所有回复 } catch (Exception es) { es.printStackTrace(); } request.setAttribute("topic_answer", array); //将结果保存在request对象中 String forward = "topic_view.jsp?forum_id=" + forum_id + "&bbs_id=" + bbs_id; forward(request, response, forward); } /** * 删除贴子以及该贴子的所有回复 * 1，获得要删除的贴子的讨论区编号forum_id以及贴子号bbs_id * 2，调用TopicHandle的delete方法，删除编号为bbs_id的贴子以及该贴子的回复 * 3，如果出现异常，将异常信息保存到request对象中 * 5，返回forums.jsp页面 */ private void topic_delete(HttpServletRequest request, HttpServletResponse response) { String bbs_id = (String) request.getParameter("bbs_id"); String forum_id = (String) request.getParameter("forum_id"); boolean isSuccess = false; try { TopicHandle.delete(Integer.valueOf(bbs_id).intValue()); isSuccess = true; } catch (Exception es) { es.printStackTrace(); isSuccess = false; request.setAttribute("topic_error", es.getMessage()); } if (isSuccess) { request.removeAttribute("topic_error"); } String forward = "topicservlet?method=topic_select&forum_id=" + forum_id; // forward += "&b