# Tips

@Configuration
public class FilterConfig {
    @Bean
    public FilterRegistrationBean filterRegistrationBean() {
        FilterRegistrationBean bean = new FilterRegistrationBean();

        bean.setFilter(requestFilter());
        // 필터 등록
        bean.addUrlPatterns(("/*"));

        return bean;
    }
    @Bean(name = "requestFilter")
    public Filter requestFilter() {
        return new RequestFilter();
    }
}

@Component
public class RequestFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException { }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        RequestWrapper wrapper = new RequestWrapper(req);
        chain.doFilter(wrapper, response);
    }

    @Override
    public void destroy() { }
}

public class RequestWrapper extends HttpServletRequestWrapper {
    private byte[] bytes;

    public RequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        // InputStream 을 byte 코드로 만듬
        bytes = IOUtils.getBytes(super.getInputStream());
    }

    public ServletInputStream getInputStream() {
        final ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
        return new ServletInputStreamImpl(bis);
    }
}