displayreturnbookservlet.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.Borrower;
import cn.edu.jmu.beans.Loan;
import cn.edu.jmu.beans.LoanRecord;
import cn.edu.jmu.beans.Title;
import cn.edu.jmu.util.MysqlUtil;
import java.io.IOException;
import java.util.Calendar;
import java.util.Date;
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 displayReturnBookServlet 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 message = "";
        String fine = "该图书无超期借阅，";
        int state = 0;
        String bid = (String) request.getParameter("bid");
        if (bid.equals("")) {
            message = "对不起，登录号不能为空，请您重新输入！";
            state = 1;
        } else {
            String[] param1 = {bid};
            String sql = "select * from loan where bid=?";
            MysqlUtil db = new MysqlUtil("java:/comp/env/jdbc/mysql");
            db.init();
            List result1 = (List) db.query(sql, param1, new BeanListHandler(LoanRecord.class));
            if (result1.isEmpty()) {
                message = "对不起，该图书并未借出或不存在，请您重新输入！";
                state = 1;
            } else {
                LoanRecord loanRecord = (LoanRecord) result1.get(0);
                String brid = String.valueOf(loanRecord.getBrid());
                Date lastBackDate = loanRecord.getLastBackDate();
                Date today = new Date();

                Calendar calendar = Calendar.getInstance();
                calendar.setTime(today);
                long timeToday = calendar.getTimeInMillis();
                calendar.setTime(lastBackDate);
                long timeLastBack = calendar.getTimeInMillis();
                long day = (timeToday - timeLastBack) / (1000 * 60 * 60 * 24);
                if (day > 0) {
                    fine="该图书已超期借阅，罚金为:"+day*0.1+"元<br>";
                }
                
                sql="select title.* from title,book where title.tid=book.tid and bid=?";
                String[] param2={bid};
                List result2 = (List) db.query(sql, param2, new BeanListHandler(Title.class));
                Title title = (Title) result2.get(0);
                float price = title.getPrice();                
                fine=fine+"如果该图书损毁，罚金为:"+price/2+"元";
                
                sql = "select loan.lid,loan.brid,loan.bid,loan.brDate," +
                        "loan.reloanDateNum,loan.lastBackDate,tname,author,volume " +
                        "from loan,book,title " +
                        "where book.bid=loan.bid and title.tid=book.tid and loan.brid=?";
                String[] param3 = {brid};
                List result3 = (List) db.query(sql, param3, new BeanListHandler(Loan.class));

                sql = "select * from borrower where brid=?";
                String[] param4={brid};
                List result4 = (List) db.query(sql, param4, new BeanListHandler(Borrower.class));                
                Borrower borrower = (Borrower) result4.get(0);
                
                request.setAttribute("bid", bid);
                request.setAttribute("fine", fine);
                request.setAttribute("result", result3);
                request.setAttribute("borrower", borrower);
            }
        }
        if (state == 0) {
            request.getRequestDispatcher("/commonReturnBook.jsp").forward(request, response);
        } else {
            String hyperlink = "<a href=\"librarianManage.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>
}