withdrawal.java

网上银行管理系统

package cn.edu.ccut;

import javax.naming.Context;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.sql.DataSource;
import java.io.PrintWriter;
import java.io.IOException;
import java.sql.*;

/**
 * Created by IntelliJ IDEA.
 * User: hvst
 * Date: 2008-8-26
 * Time: 16:01:19
 * To change this template use File | Settings | File Templates.
 */
public class WithDrawal extends HttpServlet {

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{

        String strUserId         = "";
        String strOperated       = "";
        String strOperatedMoney  = "";
        Double strLeftOver       = 0.0;
        Double nowLeftOver       = 0.0;
        String strSql            = "";
        String strSqll           = "";

        Context ctx              = null;
        DataSource ds            = null;
        Connection conn          = null;
        Statement stmt           = null;
        ResultSet rs             = null;
        PrintWriter out          = null;
        strUserId = (String)request.getSession().getAttribute("userId");

        try {
            response.setContentType("text/html;charset=gb2312");
            out = response.getWriter();

            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost/bank?useUnicode=true&characterEncoding=gb2312", "root", "");
            stmt = conn.createStatement();
            strOperatedMoney = request.getParameter("withdrawal1");

            strSql = " select leftover " +
                     " from `slimsy`" +
                     " where userid='" + strUserId + "'";
            rs = stmt.executeQuery(strSql);

            while(rs.next()){
                strLeftOver = rs.getDouble("leftover");
            }

            if(Double.parseDouble(strOperatedMoney) <= strLeftOver){
                nowLeftOver = strLeftOver- Double.parseDouble(strOperatedMoney);
                strSqll = " update `slimsy` " +
                          " set leftover='" + nowLeftOver + "'" +
                          " where userid='" + strUserId + "'";
                 stmt.executeUpdate(strSqll);

                String strSqlv="";
                strSqlv = " insert into `useroperationt` (userid,operated,timed,operatedmoney)" +
                          " values ('" + strUserId + "','2',sysdate(),'" + strOperatedMoney + "')";
                stmt.execute(strSqlv);

                RequestDispatcher dispatcher = request.getRequestDispatcher("/jsp/operate.jsp");
                dispatcher.forward(request,response);
            } else{
                out.println("<script language='javascript'>");
                out.println("   alert('取款失败！');");
                out.println("   window.history.back();");
                out.println("</script>");
            }

        } catch (Exception e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }  finally {
            try {
                if (rs != null) rs.close();
                if(stmt != null) stmt.close();
                if(conn != null) conn.close();
            } catch (SQLException e) {
                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
        }
    }
}