Spring Boot中是否有Filter类(用于web应用程序)的注释?也许@Filter ?

我想在我的项目中添加一个自定义过滤器。

Spring Boot参考指南中提到过 FilterRegistrationBean,但我不确定如何使用它。


当前回答

添加过滤器有三种方法,

用一个Spring原型(如@Component)注释你的过滤器 在Spring @Configuration中注册一个Filter类型的@Bean 在Spring @Configuration中用FilterRegistrationBean类型注册一个@Bean

Either #1 or #2 will do if you want your filter applies to all requests without customization, use #3 otherwise. You don't need to specify component scan for #1 to work as long as you place your filter class in the same or sub-package of your SpringApplication class. For #3, use along with #2 is only necessary when you want Spring to manage your filter class such as have it auto wired dependencies. It works just fine for me to new my filter which doesn't need any dependency autowiring/injection.

虽然结合#2和#3效果很好,但我很惊讶它最终没有应用两次两个过滤器。我的猜测是,当Spring调用相同的方法来创建这两个bean时,它将这两个bean合并为一个。如果您想单独使用#3和authwiring,您可以使用AutowireCapableBeanFactory。举例如下:

private @Autowired AutowireCapableBeanFactory beanFactory;

    @Bean
    public FilterRegistrationBean myFilter() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        Filter myFilter = new MyFilter();
        beanFactory.autowireBean(myFilter);
        registration.setFilter(myFilter);
        registration.addUrlPatterns("/myfilterpath/*");
        return registration;
    }

其他回答

如果您想要设置一个第三方过滤器,您可以使用FilterRegistrationBean。

例如,等价的web.xml:

<filter>
     <filter-name>SomeFilter</filter-name>
        <filter-class>com.somecompany.SomeFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>SomeFilter</filter-name>
    <url-pattern>/url/*</url-pattern>
    <init-param>
        <param-name>paramName</param-name>
        <param-value>paramValue</param-value>
    </init-param>
</filter-mapping>

这将是@Configuration文件中的两个bean:

@Bean
public FilterRegistrationBean someFilterRegistration() {

    FilterRegistrationBean registration = new FilterRegistrationBean();
    registration.setFilter(someFilter());
    registration.addUrlPatterns("/url/*");
    registration.addInitParameter("paramName", "paramValue");
    registration.setName("someFilter");
    registration.setOrder(1);
    return registration;
}

public Filter someFilter() {
    return new SomeFilter();
}

以上是用Spring Boot 1.2.3测试的。

首先,将@ServletComponentScan添加到SpringBootApplication类中。

@ServletComponentScan
public class Application {

其次,创建一个过滤器文件,扩展filter或第三方过滤器类,并像这样添加@WebFilter到这个文件:

@Order(1) //optional
@WebFilter(filterName = "XXXFilter", urlPatterns = "/*",
    dispatcherTypes = {DispatcherType.REQUEST, DispatcherType.FORWARD},
    initParams = {@WebInitParam(name = "confPath", value = "classpath:/xxx.xml")})
public class XXXFilter extends Filter{

你也可以使用@WebFilter来创建一个过滤器。这样就行了。

@Configuration
public class AppInConfig
{
    @Bean
    @Order(1)
    public FilterRegistrationBean aiFilterRegistration()
    {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new TrackingFilter());
        registration.addUrlPatterns("/**");
        registration.setOrder(1);
        return registration;
    }

    @Bean(name = "TrackingFilter")
    public Filter TrackingFilter()
    {
        return new TrackingFilter();
    }
}

添加过滤器有三种方法,

用一个Spring原型(如@Component)注释你的过滤器 在Spring @Configuration中注册一个Filter类型的@Bean 在Spring @Configuration中用FilterRegistrationBean类型注册一个@Bean

Either #1 or #2 will do if you want your filter applies to all requests without customization, use #3 otherwise. You don't need to specify component scan for #1 to work as long as you place your filter class in the same or sub-package of your SpringApplication class. For #3, use along with #2 is only necessary when you want Spring to manage your filter class such as have it auto wired dependencies. It works just fine for me to new my filter which doesn't need any dependency autowiring/injection.

虽然结合#2和#3效果很好,但我很惊讶它最终没有应用两次两个过滤器。我的猜测是,当Spring调用相同的方法来创建这两个bean时,它将这两个bean合并为一个。如果您想单独使用#3和authwiring,您可以使用AutowireCapableBeanFactory。举例如下:

private @Autowired AutowireCapableBeanFactory beanFactory;

    @Bean
    public FilterRegistrationBean myFilter() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        Filter myFilter = new MyFilter();
        beanFactory.autowireBean(myFilter);
        registration.setFilter(myFilter);
        registration.addUrlPatterns("/myfilterpath/*");
        return registration;
    }

使用@WebFilter注释,可以这样做:

@WebFilter(urlPatterns = {"/*" })
public class AuthenticationFilter implements Filter{

    private static Logger logger = Logger.getLogger(AuthenticationFilter.class);

    @Override
    public void destroy() {
        // TODO Auto-generated method stub

    }

    @Override
    public void doFilter(ServletRequest arg0, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {

         logger.info("checking client id in filter");
        HttpServletRequest request = (HttpServletRequest) arg0;
        String clientId = request.getHeader("clientId");
        if (StringUtils.isNotEmpty(clientId)) {
            chain.doFilter(request, response);
        } else {
            logger.error("client id missing.");
        }
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {
        // TODO Auto-generated method stub

    }

}