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

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

    }

}

其他回答

没有特殊的注释来表示servlet筛选器。您只需声明一个Filter类型的@Bean(或FilterRegistrationBean)。在Boot自己的EndpointWebMvcAutoConfiguration中有一个例子(为所有响应添加自定义头);

如果你只声明一个过滤器,它将被应用到所有的请求。如果您还添加了一个FilterRegistrationBean,您可以另外指定要应用的单个servlet和url模式。

注意:

从Spring Boot 1.4开始,FilterRegistrationBean不再弃用,而是简单地将包从org.springframework. Boot .context. embedd.filterregistrationbean移动到org.springframework.boot.web.servlet.FilterRegistrationBean

下面是一个在Spring Boot MVC应用程序中包含自定义过滤器的方法示例。确保在组件扫描中包含该包:

package com.dearheart.gtsc.filters;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.annotation.Profile;
import org.springframework.stereotype.Component;

@Component
public class XClacksOverhead implements Filter {

  public static final String X_CLACKS_OVERHEAD = "X-Clacks-Overhead";

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

    HttpServletResponse response = (HttpServletResponse) res;
    response.setHeader(X_CLACKS_OVERHEAD, "GNU Terry Pratchett");
    chain.doFilter(req, res);
  }

  @Override
  public void destroy() {}

  @Override
  public void init(FilterConfig arg0) throws ServletException {}

}

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{

使用Spring注册过滤器大约有四种不同的选项。

首先,我们可以创建一个实现Filter或扩展HttpFilter的Spring bean:

@Component
public class MyFilter extends HttpFilter {

    @Override
    protected void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) 
        throws IOException, ServletException {
        // Implementation details...

        chain.doFilter(request, response);
    }
}

其次,我们可以创建一个扩展GenericFilterBean的Spring bean:

@Component
public class MyFilter extends GenericFilterBean {

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
  throws IOException, ServletException {
    //Implementation details...

        chain.doFilter(currentRequest, servletResponse);
    }
}

我们也可以使用FilterRegistrationBean类:

@Configuration
public class FilterConfiguration {

    private final MyFilter myFilter;

    @Autowired
    public FilterConfiguration(MyFilter myFilter) {
        this.myFilter = myFilter;
    }

    @Bean
    public FilterRegistrationBean<MyFilter> myFilterRegistration() {
        FilterRegistrationBean<DateLoggingFilter> filterRegistrationBean = new FilterRegistrationBean<>();
        filterRegistrationBean.setFilter(myFilter);
        filterRegistrationBean.setUrlPatterns(Collections.singletonList("/*"));
        filterRegistrationBean.setDispatcherTypes(DispatcherType.REQUEST);
        filterRegistrationBean.setOrder(Ordered.LOWEST_PRECEDENCE - 1);
        return filterRegistrationBean;
    }
}

最后,我们可以使用@ServletComponentScan的@WebFilter注释:

@WebFilter(urlPatterns = "/*", dispatcherTypes = {DispatcherType.REQUEST})
public class MyFilter extends HttpFilter {

    @Override
    protected void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
  throws IOException, ServletException {
        // Implementation details...

        chain.doFilter(request, response);
    }
}

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。