cancel.java

网上银行管理系统

package cn.edu.ccut;

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

/**
 * Created by IntelliJ IDEA.
 * User: hvst
 * Date: 2008-8-27
 * Time: 15:11:18
 * To change this template use File | Settings | File Templates.
 */
public class Cancel extends HttpServlet {
     public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
     }



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

        String strSql        = "";
        String strSqll       = "";
        String strSqlll      = "";
        Double strLeftOver   = 0.0;

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

        try {
            response.setContentType("text/html;charset=gb2312");
            out = response.getWriter();
            Class.forName("com.mysql.jdbc.Driver"); //向driver manager中注册一个maysql的jdbc driver
            conn = DriverManager.getConnection("jdbc:mysql://localhost/bank?useUnicode=true&characterEncoding=gb2312", "root", "");

            stmt = conn.createStatement();

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

            while(rs.next()){
                 strLeftOver = rs.getDouble("leftover");
            }
             if(strLeftOver <= 0.0){
                strSqll = " delete " +
                          " from `useroperationt` " +
                          " where userid=' " + strUserId + " ' ";
                strSqlll = " delete " +
                           " from `enrollmessaget`" +
                           " where userid=' " + strUserId + " ' ";
                stmt.execute(strSqll);
                stmt.execute(strSqlll);

                response.sendRedirect("/liu/jsp/enroll.jsp");
             }
            else{
                out.println("<script language='javascript'>");
                out.println("   alert('操作失败！');");
                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.
            }
        }
    }
}