queryprivilegeservlet.java

图书馆管理系统！利用java的mvc开发！

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package cn.edu.jmu.jc;

import cn.edu.jmu.beans.Privilege;
import cn.edu.jmu.util.MysqlUtil;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.dbutils.handlers.BeanListHandler;

/**
 *
 * @author jiangchen
 */
public class queryPrivilegeServlet extends HttpServlet {
   
    /** 
    * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
    * @param request servlet request
    * @param response servlet response
    */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        request.setCharacterEncoding("UTF-8");
    } 

    // <editor-fold defaultstate="collapsed" desc="HttpServlet 方法。单击左侧的 + 号以编辑代码。">
    /** 
    * Handles the HTTP <code>GET</code> method.
    * @param request servlet request
    * @param response servlet response
    */
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
        if (request.getHeader("referer") == null) {
            response.sendRedirect("adminIndex.jsp");
        } else {
            doPost(request, response);
        }
    } 

    /** 
    * Handles the HTTP <code>POST</code> method.
    * @param request servlet request
    * @param response servlet response
    */
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
        String message = "";
        int state = 0;
        String ptype = (String) request.getParameter("ptype");
        if (ptype.equals("")) {
            message = "对不起，权限类型不能为空，请您重新输入！";
            state = 1;
        } else {
            String[] param = {ptype};
            String sql = "select * from privilege where ptype=?";
            MysqlUtil db = new MysqlUtil("java:/comp/env/jdbc/mysql");
            db.init();
            List result = (List) db.query(sql, param, new BeanListHandler(Privilege.class));
            if (result.isEmpty()) {
                message = "对不起，该权限类型不存在，请您重新输入！";
                state = 1;
            } else {
                Privilege privilege = (Privilege) result.get(0);                
                request.setAttribute("privilege", privilege);
            }
        }
        if (state == 0) {
            request.getRequestDispatcher("/modifyPrivilege.jsp").forward(request, response);
        } else {
            String hyperlink = "<a href=\"queryPrivilege.jsp\">返回</a>";
            request.setAttribute("title", "操作失败！");
            request.setAttribute("message", message);
            request.setAttribute("hyperlink", hyperlink);
            request.getRequestDispatcher("/result.jsp").forward(request, response);
        }
    }

    /** 
    * Returns a short description of the servlet.
    */
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}