input输入值以后，后端servlet通过getparameter（name）获取的值为空
上代码：login.jsp的代码 验证页面 账号：
密码：
Login包的代码package data;public class Login { String userid,username,passwd,backNews,ipaddress=""; boolean success = false; public void setUserid(String userid) { this.userid = userid; } public String getUserid() { return userid; } public void setUsername(String username) { this.username = username; } public String getUsername() { return username; } public void setPasswd(String passwd) { this.passwd = passwd; } public String getPasswd() { return passwd; } public String getBackNews() { return backNews; } public void setBackNews(String s) { this.backNews = s; } public void setIpaddress(String ipaddress) { this.ipaddress = ipaddress; } public String getIpaddress() { return ipaddress; } public void setSuccess(boolean b) { this.success = b; } public boolean getSuccess() { return success; }}servlet的代码package servlet;import data.*;import data.Login;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.sql.*;import java.io.*;import javax.servlet.*;import javax.servlet.http.*;@WebServlet(name = "HandleLogin")public class HandleLogin extends HttpServlet { @Override public void init(ServletConfig config) throws ServletException { super.init(config); try{ Class.forName("com.mysql.jdbc.Driver"); } catch (Exception e){} } public String handleString(String s){ try { byte bb[] = s.getBytes("iso-8859-1"); s=new String(bb); } catch (Exception ee){} return s; } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Connection con; Statement sql; Login loginBean = null; String backNews = ""; HttpSession session = request.getSession(true); try { loginBean = (Login)session.getAttribute("login"); if (loginBean == null) { loginBean = new Login(); session.setAttribute("login", loginBean); } } catch (Exception ee) { loginBean = new Login(); session.setAttribute("login", loginBean); } String userid = request.getParameter("userid").trim(); String passwd = request.getParameter("passwd").trim(); boolean ok = loginBean.getSuccess(); userid = handleString(userid); passwd = handleString(passwd); if (ok == true && userid.equals(loginBean.getUserid())) { backNews = userid + "已经登录了"; loginBean.setBackNews(backNews); } else { String url = "jdbc:mysql://localhost:3306/hanfu"; boolean boo = (userid.length() > 0) && (passwd.length() > 0); try { con = DriverManager.getConnection(url, "root", ""); String condition = "select * from users where userid='" + userid + "'and passwd ='" + passwd + "'"; sql = con.createStatement(); if (boo) { ResultSet rs = sql.executeQuery(condition); boolean m = rs.next(); if (m == true) { backNews = "登陆成功"; loginBean.setBackNews(backNews); loginBean.setSuccess(true); loginBean.setUserid(userid); System.out.println("登陆成功"); } else { backNews = "用户名或密码错误"; loginBean.setBackNews(backNews); loginBean.setSuccess(false); loginBean.setUserid(userid); loginBean.setPasswd(passwd); System.out.println("用户名或密码错误"); } } else { backNews = "用户名或密码错误"; loginBean.setBackNews(backNews); loginBean.setSuccess(false); loginBean.setUserid(userid); System.out.println("用户名或密码错误"); }// else {// backNews="用户名或密码错误";// loginBean.setBackNews(backNews);// loginBean.setSuccess(false);// loginBean.setUserid(userid);// loginBean.setPasswd(passwd);// } con.close(); } catch(SQLException exp){ backNews = "" + exp; loginBean.setBackNews(backNews); loginBean.setSuccess(false); } } RequestDispatcher dispatcher = request.getRequestDispatcher("hanfu_showlogin.jsp"); dispatcher.forward(request,response); }// public String getIpAddr(HttpServletRequest request) {// String ip = request.getHeader("x-forwarded-for");// if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {// ip = request.getHeader("Proxy-Client-IP");// }// if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {// ip = request.getHeader("WL-Proxy-Client-IP");// }// if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {// ip = request.getRemoteAddr();// }// if(ip.startsWith("192")){}// else{ip="";}// return ip;// } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); }}然后loginshow的跳转代码 登录情况
登陆成功
登陆账号为：
登录失败
你输入的账号为：
你输入的密码为：
我是才学jsp的小白。。。真的没想到照着书打也会有这么多问题，我真的太笨了无论我在login输入什么数值，最后loginshow的页面出现的值都为空 |
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