displayaddbookservlet.java

图书馆管理系统！利用java的mvc开发！

/*
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 * and open the template in the editor.
 */
package cn.edu.jmu.jc;

import cn.edu.jmu.beans.Book;
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 displayAddBookServlet 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 tid = request.getParameter("tid");
        String isbn = request.getParameter("isbn");
        String collectNum =request.getParameter("collectNum");
        int bid = 0;
        String sql = "select * from book where bid=(select max(bid) from book)";
        MysqlUtil db = new MysqlUtil("java:/comp/env/jdbc/mysql");
        db.init();
        List result = (List) db.query(sql, new BeanListHandler(Book.class));
        if (result.isEmpty()) {
            bid = 1000001;
        } else {
            Book book = (Book) result.get(0);
            bid = book.getBid() + 1;
        }
        request.setAttribute("tid", tid);
        request.setAttribute("bid", bid);
        request.setAttribute("isbn", isbn);
        request.setAttribute("collectNum", collectNum);
        request.getRequestDispatcher("/addBook.jsp").forward(request, response);
    }

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