在Spring Boot中自定义filter
本文我们将会讲解如何在Spring Boot中自定义filter并指定执行顺序。
定义Filter很简单，我们只需要实现Filter接口即可，同时我们可指定@Order来确定其执行顺序，我们定义两个filter如下：
@Slf4j @Component @Order(1) public class TransactionFilter implements Filter { @Override public void doFilter( ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest) request; log.info( "Starting a transaction for req : {}", req.getRequestURI()); chain.doFilter(request, response); log.info( "Committing a transaction for req : {}", req.getRequestURI()); } // other methods }
@Slf4j @Component @Order(2) public class RequestResponseLoggingFilter implements Filter { @Override public void doFilter( ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest req = (HttpServletRequest) request; HttpServletResponse res = (HttpServletResponse) response; log.info( "Logging Request {} : {}", req.getMethod(), req.getRequestURI()); chain.doFilter(request, response); log.info( "Logging Response :{}", res.getContentType()); } // other methods }
注意在Spring Boot中我们需要使用@Component来实例化Filter从而在Spring Boot中生效。
@Order指定了两个fiter的顺序。
上面的例子我们指定了两个fiter对于所有的url生效，如果我们希望filter对于特定的某些url生效该怎么办呢？
我们可使用FilterRegistrationBean来手动注册对于的Filter：
@Bean public FilterRegistrationBean<UrlFilter> loggingFilter(){ FilterRegistrationBean<UrlFilter> registrationBean = new FilterRegistrationBean<>(); registrationBean.setFilter(new UrlFilter()); registrationBean.addUrlPatterns("/users/*"); return registrationBean; }
