logging.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: 2008-8-21
 * Time: 13:25:19
 * To change this template use File | Settings | File Templates.
 */
public class    Logging extends HttpServlet {

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

        String strLogging      = "";
        String strPW           = "";
        String strUserId       = "";
        String strUserPassWord = "";
        String strSql          = "";

        Context ctx     = null;
        DataSource ds   = null;
        Connection conn = null;
        Statement stmt  = null;
        ResultSet rs    = null;
        PrintWriter out = null;
        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();

            strLogging = request.getParameter("userid");
            strPW = request.getParameter("userpassword");
            request.getSession().setAttribute("userId",strLogging); //创建session会话！！

            strSql = " select userpassword " +
                    " from `enrollmessaget`" +
                    " where userid='" + strLogging + "'";
            rs = stmt.executeQuery(strSql);
            String strPassWord = "";

            while (rs.next()) {
                strPassWord = rs.getString("userpassword");
            }
            if (strPW.trim().equals(strPassWord.trim())) {
                RequestDispatcher dispatcher = request.getRequestDispatcher("/jsp/operate.jsp");
                dispatcher.forward(request,response);
            } else {
                out.println("<script language='javascript'>");
                out.println("alert('登录失败,请输入正确的帐号密码');");
                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.
            }

        }
    }
}