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;
}
上面我们同时指定了filter对应的urlPatttern。
本文的例子可以参考 https://github.com/ddean2009/learn-springboot2/tree/master/springboot-filter
更多教程请参考 flydean的博客