springboot javax.servlet.Filter使用

请求拦截器优点：

1、拦截非法请求重定向
2、验证用户token

下面是demo程序，有问题的可以在评论区留言

@WebFilter(filterName = "authenticationFilter", urlPatterns = {"/user/*","/detail/*"})
public class AuthenticationFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest servletRequest = (HttpServletRequest) request;
        HttpSession session        = servletRequest.getSession();
        Object             object         = session.getAttribute(Constant.USER_SESSION_NAME);
        if (Objects.isNull(object)) {
            HttpServletResponse servletResponse = (HttpServletResponse) response;
            servletResponse.sendRedirect("/login");
        } else {
            chain.doFilter(request, response);
        }
    }

    
    @Override
    public void destroy() {

    }
}

代码逻辑比较简单易懂。根据springboot的自动配置特性，这样写，就可以达到用户在请求 /user 和 /detail 开头的请求的时候进行过滤了。