FormServlet
package servlet;
import java.io.IOException;
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 util.TokenProcessor;
/**
* Servlet implementation class FormServlet
*/
public class FormServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String token = TokenProcessor.getInstance().makeToken();
request.getSession().setAttribute("token", token);
request.getRequestDispatcher("/form.jsp").forward(request, response);
}
}
form.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>form表单</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/DoFormServlet"
method="post">
<input type="hidden" name="token" value="${token}" /> 用户名：<input
type="text" name="username"><input type="submit" value="提交">
</form>
</body>
</html>
提交DoFormServlet
package servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class DoFormServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public DoFormServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
boolean b = isRepeatSubmit(request);
if(b){
System.out.println("请不要重复提交");
return;
}
request.getSession().removeAttribute("token");//移除session中的token
System.out.println("处理用户提交请求！！");
}
private boolean isRepeatSubmit(HttpServletRequest request){
String client_token = request.getParameter("token");
if(client_token == null){
return true;
}
String server_token = (String) request.getSession().getAttribute("token");
if(server_token == null){
return true;
}
if(!client_token.equals(server_token)){
return true;
}
return false;
}
}
时间： 2024-11-03 05:20:54