使用FilterRegistrationBean自定义过滤器拦截

过滤器

public class TimeFilter implements Filter {

    /* (non-Javadoc)
     * @see javax.servlet.Filter#destroy()
     */
    @Override
    public void destroy() {
        System.out.println("time filter destroy");
    }

    /* (non-Javadoc)
     * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
     */
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        System.out.println("time filter start");
        long start = System.currentTimeMillis();
        chain.doFilter(request, response);
        System.out.println("time filter 耗时:"+ (System.currentTimeMillis() - start));
        System.out.println("time filter finish");
    }

    /* (non-Javadoc)
     * @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
     */
    @Override
    public void init(FilterConfig arg0) throws ServletException {
        System.out.println("time filter init");
    }
}

配置过滤器

@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {

    @Bean
    public FilterRegistrationBean timeFilter(){
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        TimeFilter timeFilter = new TimeFilter();
        registrationBean.setFilter(timeFilter);

        List<String> urls = new ArrayList<>();
        urls.add("/*");
        registrationBean.setUrlPatterns(urls);

        return registrationBean;
    }

}

这样写和在过滤器上写一个 @Component注解是一样的，
但是这样写有一个好处，也可以指定过滤器过滤哪些路径