登录页面跳转与错误提示信息

---恢复内容开始---

//主界面信息的处理

 package day13;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;

public class Myservlet extends HttpServlet {

protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

//解决乱码
request.setCharacterEncoding("UTF-8");
//1 2判断用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");

bank qyuser=null;
//2 调用login(username,password); 进行查询用户是否存在
try {
qyuser=login1(username,password);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//3 通过接结果值 是否为null 判断用户名是否正确
if(qyuser!=null){
//用户名密码正确 登录首页
//3获得用户输入的验证码
String check_client = request.getParameter("checkCode");
//4 获得这个成语
String checkOde =(String) request.getSession().getAttribute("checkcode_session");
if(!checkOde.equals(check_client)){
request.setAttribute("loginFo", "您的验证码不正确");
request.getRequestDispatcher("/login.jsp").forward(request, response);

}
else{
request.getRequestDispatcher("/index.jsp").forward(request, response);
}


}else{
//用户名错误

request.setAttribute("loginInfo", "用户名或者密码错误");
request.getRequestDispatcher("/login.jsp").forward(request, response);

}
}

public bank login1(String username, String password) throws SQLException {
QueryRunner qu = new QueryRunner(JDBCUtils.getDataSource());
String sql="select * from bank where username=? and password=?";

bank query = qu.query(sql, new BeanHandler <bank>(bank.class),username,password);
return query;

}

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

doGet(request, response);
}

}

//错误信息的处理

<div><%=request.getAttribute("loginFo")==null?"":request.getAttribute("loginFo") %></div>

<div><%=request.getAttribute("loginInfo")==null?"":request.getAttribute("loginInfo") %></div>

原文地址:https://www.cnblogs.com/Fisherman13/p/10480252.html