returnbookservlet.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.util.MysqlUtil;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author jiangchen
 */
public class returnBookServlet 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 bid = request.getParameter("bid");
        String sql="delete from loan where bid=?";
        String[] param1={bid};
        MysqlUtil db = new MysqlUtil("java:/comp/env/jdbc/mysql");
        db.init();
        db.update(sql, param1);
        
        sql="update book set brState=? where bid=?";
        String[] param2={"可供出借",bid};
        db.update(sql, param2);
        
        request.getRequestDispatcher("/librarianManage.jsp").forward(request, response);
    }

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

}