Springboot项目如何创建Filter

方式一：使用@WebFilter+@ServletComponentScan

1）创建类com.zhi.demo.filter.CustomFilter1，添加注解@WebFilter(urlPatterns = { "/test1/*" })，urlPatterns表示需要过滤的地址

@WebFilter(urlPatterns = { "/test1/*" })
public class CustomFilter1 implements Filter {
    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        logger.info("请求{}经过过滤器", httpServletRequest.getRequestURI());
        chain.doFilter(request, response);
    }
}

2）在启动类上添加注解@ServletComponentScan(basePackages = "com.zhi.demo.filter")

@ServletComponentScan(basePackages = "com.zhi.demo.filter")
@SpringBootApplication
public class InterceptApplication {
    public static void main(String[] args) {
        new SpringApplicationBuilder(InterceptApplication.class).bannerMode(Mode.OFF).run(args);
    }
}

方式二：使用FilterRegistrationBean注册拦截器

1）创建类com.zhi.demo.filter.CustomFilter2

public class CustomFilter2 implements Filter {
    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        logger.info("请求{}经过过滤器", httpServletRequest.getRequestURI());
        chain.doFilter(request, response);
    }
}

2）使用FilterRegistrationBean载入过滤器，并只对/test2/*进行拦截

@Configuration
public class BeanConfig {
    @Bean
    public FilterRegistrationBean<CustomFilter2> filterRegistrationBean() {
        FilterRegistrationBean<CustomFilter2> registration = new FilterRegistrationBean<>();
        registration.setFilter(new CustomFilter2());
        registration.addUrlPatterns("/test2/*");
        return registration;
    }
}

 

注意：

1、使用@Component注解时，也可以将Filter注册到容器中，但@WebFilter配置信息会失效

2、同时使用上面的2种方式，会两次拦截