【Spring Security入门】04-自定义-Filter

本文解决问题

将自定义的 Filter 加入到 Spring Security 中的 Filter 链中的指定位置。

Spring Security 默认的过滤器链

官网位置：

别名 类名称 Namespace Element or Attribute CHANNEL_FILTER ChannelProcessingFilter http/intercept-url-channel SECURITY_CONTEXT_FILTER SecurityContextPersistenceFilter http CONCURRENT_SESSION_FILTER ConcurrentSessionFilter session-management/concurrency-control HEADERS_FILTER HeaderWriterFilter http/headers CSRF_FILTER CsrfFilter http/csrf LOGOUT_FILTER LogoutFilter http/logout X509_FILTER X509AuthenticationFilter http/x509 PRE_AUTH_FILTER AbstractPreAuthenticatedProcessingFilter( Subclasses) N/A CAS_FILTER CasAuthenticationFilter N/A FORM_LOGIN_FILTER UsernamePasswordAuthenticationFilter http/form-login BASIC_AUTH_FILTER BasicAuthenticationFilter http/http-basic SERVLET_API_SUPPORT_FILTER SecurityContextHolderAwareRequestFilter http/-api-provision JAAS_API_SUPPORT_FILTER JaasApiIntegrationFilter http/-api-provision REMEMBER_ME_FILTER RememberMeAuthenticationFilter http/remember-me ANONYMOUS_FILTER AnonymousAuthenticationFilter http/anonymous SESSION_MANAGEMENT_FILTER SessionManagementFilter session-management EXCEPTION_TRANSLATION_FILTER ExceptionTranslationFilter http FILTER_SECURITY_INTERCEPTOR FilterSecurityInterceptor http SWITCH_USER_FILTER SwitchUserFilter N/A

过滤器顺序从上到下

自定义 Filter

自定义的 Filter 建议继承 GenericFilterBean，本文示例：

public class BeforeLoginFilter extends GenericFilterBean {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("This is a filter before UsernamePasswordAuthenticationFilter.");
        // 继续调用 Filter 链
        filterChain.doFilter(servletRequest, servletResponse);
    }
}

配置自定义 Filter 在 Spring Security 过滤器链中的位置

配置很简单，本文示例：

protected void configure(HttpSecurity http) throws Exception {
        http
                .authorizeRequests()
                .antMatchers("/").permitAll()
                .antMatchers("/user/**").hasRole("USER")
                .and()
                .formLogin().loginPage("/login").defaultSuccessUrl("/user")
                .and()
                .logout().logoutUrl("/logout").logoutSuccessUrl("/login");

        // 在 UsernamePasswordAuthenticationFilter 前添加 BeforeLoginFilter
        http.addFilterBefore(new BeforeLoginFilter(), UsernamePasswordAuthenticationFilter.class);

        // 在 CsrfFilter 后添加 AfterCsrfFilter
        http.addFilterAfter(new AfterCsrfFilter(), CsrfFilter.class);
    }

说明： HttpSecurity 有三个常用方法来配置：

addFilterBefore(Filter filter, Class<? extends Filter> beforeFilter) 在 beforeFilter 之前添加 filter addFilterAfter(Filter filter, Class<? extends Filter> afterFilter) 在 afterFilter 之后添加 filter addFilterAt(Filter filter, Class<? extends Filter> atFilter) 在 atFilter 相同位置添加 filter， 此 filter 不覆盖 filter

通过在不同 Filter 的 doFilter() 方法中加断点调试，可以判断哪个 filter 先执行，从而判断 filter 的执行顺序 。