querybookservlet.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.Title;
import cn.edu.jmu.util.MysqlUtil;
import java.io.IOException;
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 queryBookServlet 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("index.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 tname=request.getParameter("tname");
        String author=request.getParameter("author");
        String press=request.getParameter("press");
        String isbn=request.getParameter("isbn");
        if(tname.equals("")){
            tname="%";
        }else{
            tname="%"+tname+"%";
        }
        if(author.equals("")){
            author="%";
        }else{
            author="%"+author+"%";
        }
        if(press.equals("")){
            press="%";
        }else{
            press="%"+press+"%";
        }
        if(isbn.equals("")){
            isbn="%";
        }
        
        String[] param={tname,author,press,isbn};
        String sql="select * from title where tname like ? and author like ? and press like ? and isbn like ? ";
        MysqlUtil db = new MysqlUtil("java:/comp/env/jdbc/mysql");
        db.init();
        List result=(List) db.query(sql, param, new BeanListHandler(Title.class));
        request.setAttribute("result", result);
        request.getRequestDispatcher("/queryResult.jsp").forward(request, response);
    }

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

}