使用过滤器的Javaservlet重定向_Java_Servlets_Servlet Filters

使用过滤器的Javaservlet重定向

java servlets

使用过滤器的Javaservlet重定向,java,servlets,servlet-filters,Java,Servlets,Servlet Filters,我有以下问题：我有一个带有登录表单的index.html页面： <html> <head> <title>TODO supply a title</title> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> &l

我有以下问题：

我有一个带有登录表单的

index.html

页面：

<html>
    <head>
        <title>TODO supply a title</title>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <link href="css/css.css" type="text/css" rel="stylesheet"/>
    </head>
    <body>
        <nav>
            <form action="">
                <label for="username">User: </label><input name ="username" type="text">
                <label for="password">Password: </label><input name ="password" type="password">
                <input type="submit" value="Vai">
            </form>
        </nav>

        <section id ="page">

        </section>
    </body>
</html>

下面是

f2

过滤器：

public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain)
            throws IOException, ServletException {

        if (debug) {
            log("f2:doFilter()");
        }

        doBeforeProcessing(request, response);
        HttpServletRequest req = (HttpServletRequest) request;
        if(req.getSession().getAttribute("username") == null)
            System.out.println("Attributo username = NULL");
        if(!req.getParameter("username").equals("admin")){
            System.out.println("Username is not ADMIN");
            req.getRequestDispatcher("/payroll/public/dipendenti.html").forward(request, response);
        }
        else{
            System.out.println("Username is ADMIN");
            req.getRequestDispatcher("/payroll/private/stipendi.html").forward(request, response);
        }
        Throwable problem = null;
        try {
            chain.doFilter(request, response); return;
        } catch (Throwable t) {
        // If an exception is thrown somewhere down the filter chain,
            // we still want to execute our after processing, and then
            // rethrow the problem after that.
            problem = t;
            t.printStackTrace();
        }

        doAfterProcessing(request, response);

    // If there was a problem, we want to rethrow it if it is
        // a known type, otherwise log it.
        if (problem != null) {
            if (problem instanceof ServletException) {
                throw (ServletException) problem;
            }
            if (problem instanceof IOException) {
                throw (IOException) problem;
            }
            sendProcessingError(problem, response);
        }
    }

我重温了一些事情：

我有一个无限循环，因为我的过滤器

f2

具有

url模式=/*

，因此它捕获每个请求，对其进行细化，发送它，并重新匹配刚刚发送的相同请求。一遍又一遍

这名男子说，我必须将我的

url模式

更改为其他模式。但是什么呢？如果我创建一个名为。。。比如说

myRedirectServlet.java

，在

index.html

：

action=“myRedirectServlet”

或只是

action=“/payroll/”

，而不创建任何servlet？我很抱歉，但我很困惑

请帮帮我

你所做的事不符合安全利益。你应该利用的概念-但让我们把它留到另一天

HTML中的表单操作丢失-因此，当您点击提交时，浏览器将尝试重定向到同一HTML页面

假设您对此很满意-将过滤器映射更改为仅映射到该HTML页面

在过滤器内部-如果用户id为空-只要（不重定向），如果用户id是管理员重定向（根据需要），因为您的过滤器现在是特定的-您将不会进入无限循环

编辑：我总是被重定向到

/payroll/public/dipendenti.html

，即使我的用户名不是“admin”，我也不知道为什么，我刚刚开始学习它，所以在这一点上我并没有真正考虑安全性。顺便说一下，在我的表单

action

字段中添加我想要到达的页面的路径：

/payroll/private/stipendi.html

，然后放入

else

语句

chain.doFilter（请求、响应）但我总是被重定向到/payroll/private/stipendi.html。。。我不明白为什么
public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain)
            throws IOException, ServletException {

        if (debug) {
            log("f2:doFilter()");
        }

        doBeforeProcessing(request, response);
        HttpServletRequest req = (HttpServletRequest) request;
        if(req.getSession().getAttribute("username") == null)
            System.out.println("Attributo username = NULL");
        if(!req.getParameter("username").equals("admin")){
            System.out.println("Username is not ADMIN");
            req.getRequestDispatcher("/payroll/public/dipendenti.html").forward(request, response);
        }
        else{
            System.out.println("Username is ADMIN");
            req.getRequestDispatcher("/payroll/private/stipendi.html").forward(request, response);
        }
        Throwable problem = null;
        try {
            chain.doFilter(request, response); return;
        } catch (Throwable t) {
        // If an exception is thrown somewhere down the filter chain,
            // we still want to execute our after processing, and then
            // rethrow the problem after that.
            problem = t;
            t.printStackTrace();
        }

        doAfterProcessing(request, response);

    // If there was a problem, we want to rethrow it if it is
        // a known type, otherwise log it.
        if (problem != null) {
            if (problem instanceof ServletException) {
                throw (ServletException) problem;
            }
            if (problem instanceof IOException) {
                throw (IOException) problem;
            }
            sendProcessingError(problem, response);
        }
    }