Springboot实现过滤器

Springboot实现过滤器有以下俩种方式，第一种方式俩步走，即向spring容器注册filter

第一种：

1.Filter过滤器具体实现类

@Component
@Slf4j
public class MyTestFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("[ {} ] 创建啦...", this.getClass().getSimpleName());
    }
 
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        log.info("[ {} ] 执行啦...", this.getClass().getSimpleName());
 
        chain.doFilter(request, response);
    }
 
    @Override
    public void destroy() {
        log.info("[ {} ] 被摧毁啦...", this.getClass().getSimpleName());
    }
}

2.向spring容器注册filter

@Configuration
public class FilterConfig {
 
    @Resource
    private MyTestFilter myTestFilter;
 
    @Bean
    public FilterRegistrationBean testFilterRegistration() {
        FilterRegistrationBean registration = new FilterRegistrationBean(myTestFilter);
        registration.addUrlPatterns("/filter/*");
        registration.setName("testFilter");
        registration.setOrder(1);
        return registration;
    }
}

 第二种：

通过@WebFilter 注解来配置

@Component
@WebFilter(urlPatterns = "/filter/*", filterName = "myTestFilter") 
@Slf4
public class MyTestFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("[ {} ] 创建啦...", this.getClass().getSimpleName());
    }
 
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        log.info("[ {} ] 执行啦...", this.getClass().getSimpleName());
 
        chain.doFilter(request, response);
    }
 
    @Override
    public void destroy() {
        log.info("[ {} ] 被摧毁啦...", this.getClass().getSimpleName());
    }
}

还需要在 SpringBootApplication 上使用@ServletComponentScan

注解后
Servlet可以直接通过@WebServlet注解自动注册
Filter可以直接通过@WebFilter注解自动注册
Listener可以直接通过@WebListener 注解自动注册