10、springboot实现过滤器

方式一：注解方式

创建一个过滤器包-》创建过滤器类并实现Filter类，注意是javax.servlet-》重载过滤器的doFilter方法-》在过滤器类头上面加上注释@WebFilter(urlPatterns = “/dofilter”)-》在主入口类上面同样加入注释@ServletComponentScan(basePackages = “com.demo.demo.filter”)

@WebFilter(urlPatterns = "/dofilter")
public class MyFilter implements Filter {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("======================过滤器=======================");
        filterChain.doFilter(servletRequest,servletResponse);
    }
}

过滤器类

@SpringBootApplication
@ServletComponentScan(basePackages = "com.demo.demo.filter")
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

主函数

方式二：配置文件方式

创建过滤器包和类实现Filter方法，重载doFilter，和上面一样，但是不需要在加注释，只需要新建一个配置包和配置类，配置类上面加上@Configuration

@Configuration
public class FilterConfig {
    @Bean
    public FilterRegistrationBean myFilterRegistrationBean(){
        FilterRegistrationBean filterRegistrationBean=new FilterRegistrationBean();
        filterRegistrationBean.addUrlPatterns("/user/**");
        return filterRegistrationBean;
    }
}