springboot @WebFilter过滤器的使用

过滤器的用法就不多说了

新建Filter的继承类：MemberFilter（放置包需要注意）

@WebFilter(urlPatterns = "/*")
@Order(1)
public class MemberFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.err.println("自定义过滤器MemberFilter->doFilter");
    }

    @Override
    public void destroy() {

    }
}

配合@order使用，生命排序。

过滤器不在启动类扫描范围时，需要注意的是在启动类需要添加@ServletComponentScan扫描，其中包名自定义

@ServletComponentScan(basePackages = {"com.example.controller.filter"})

使用bean的情况下，jar打包是可以直接@Autowired使用的，转换war打包方式部署，获取的bean为null，这时候只能手动添加了

新建@Configuration注解类：FilterRegistrationConfig

@Configuration
public class FilterRegistrationConfig {

    @Bean
    public MemberFilter memberFilter() {
        return new MemberFilter();
    }

    @Bean
    public FilterRegistrationBean filterProxy() {
        FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        DelegatingFilterProxy httpBasicFilter = new DelegatingFilterProxy();
        registrationBean.setFilter(httpBasicFilter);
        Map<String, String> m = new HashMap<String, String>();
        m.put("targetBeanName", "memberFilter");
        m.put("targetFilterLifecycle", "true");
        registrationBean.setInitParameters(m);
        List<String> urlPatterns = new ArrayList<String>();
        urlPatterns.add("/*");
        registrationBean.setUrlPatterns(urlPatterns);
        return registrationBean;
    }
}

　这时候还需要注意假若使用了shiro，况且上述注册的过滤器有使用到的情况下，shiroFiler的过滤必须定义在前（解决shiro报错找不到原因）

    @Bean
    public FilterRegistrationBean delegatingFilterProxy() {
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        DelegatingFilterProxy proxy = new DelegatingFilterProxy();
        proxy.setTargetFilterLifecycle(true);
        proxy.setTargetBeanName("shiroFilter");
        filterRegistrationBean.setFilter(proxy);
        return filterRegistrationBean;
    }