messegedetailservlet.java

学生信息管理系统 jsp + sql + javabean 实现

package sms.servlet;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import sms.db.*;
import java.sql.*;
import sms.bean.*;

public class MessegeDetailServlet extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GBK";

    public void init() throws ServletException {
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        response.setContentType(CONTENT_TYPE);
        request.setCharacterEncoding("gb2312");
        String messegeId = request.getParameter("messegeId");
        String sql0 =
                "update messege_info set browse_num = browse_num+1 where id ='" +
                messegeId + "'";
        String sql1 = "select * from messege_info where id='" +messegeId +"'";
        String sql2 = "select * from messege_answer_info where messege_id='" +
                      messegeId + "'";
        String sql3 = "select * from comment_info where messege_id='" +
                      messegeId + "' order by add_time desc";

        MessegeDetailBean messegeDetailBean = null;
        DBAccess dba = new DBAccess();
        try {
            dba.getConnection();
            dba.executeSql(sql0); //更新此消息的浏览数
            ResultSet rs = dba.query(sql1); //查询消息的详细信息
            if (rs != null && rs.next()) {
                messegeDetailBean = new MessegeDetailBean();
                messegeDetailBean.setBrowseNum(rs.getInt("browse_num"));
                messegeDetailBean.setTopic(rs.getString("topic"));
                messegeDetailBean.setAuthor(rs.getString("author"));
                messegeDetailBean.setMessegeId(rs.getString("id"));
                messegeDetailBean.setContent(rs.getString("content"));
                messegeDetailBean.setColumnName(rs.getString("column_id"));
                messegeDetailBean.setScoreNum(rs.getInt("score_num"));
                messegeDetailBean.setTotalScore(rs.getInt("total_score"));
                messegeDetailBean.setAddTime(rs.getString("add_time"));
                rs = null;
                rs = dba.query(sql2);//查询该留言板信息的全部评论信息
                AnswerBean answerBean = new AnswerBean();
                if (rs != null && rs.next()) {
                  answerBean.setAddTime(rs.getString("answer_time"));
                  answerBean.setContent(rs.getString("content"));
                  answerBean.setTreatDepartment(rs.getString("answer_department"));
                }
                messegeDetailBean.setAnswerBean(answerBean);
                rs = null;
                rs = dba.query(sql3);//查询该留言板信息的全部评论信息
                if (rs != null) {
                    ArrayList commentList = new ArrayList();
                    while (rs.next()) {//通过循环得到评论信息内容
                        CommentBean commentBean = new CommentBean();
                        commentBean.setAddTime(rs.getString("add_time"));
                        commentBean.setTitle(rs.getString("title"));
                        commentBean.setContent(rs.getString("content"));
                        commentBean.setAuthor(rs.getString("author"));
                        commentBean.setMessegeId(rs.getString("messege_id"));
                        commentBean.setId(rs.getString("id"));
                        commentList.add(commentBean);
                    }
                    messegeDetailBean.setCommentList(commentList);//将评论信息组成的ArrayList保存到MessegeDetailBean的属性中
                }
            }
        } catch (SQLException ex) {
        } finally {
            dba.closeConnection();
        }
        request.setAttribute("messegeDetailBean", messegeDetailBean);
        RequestDispatcher dispatcher = request.getRequestDispatcher(
                "/messegeDetail.jsp");
        dispatcher.forward(request, response);
    }

    //Process the HTTP Post request
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        doGet(request, response);
    }

    //Clean up resources
    public void destroy() {
    }
}