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);
    }
}

其他回答

你可以在实现javax.servlet.Filter的类上使用@WebFilter javax.servlet.annotation.WebFilter:

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

然后使用@ServletComponentScan注册。

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

    }

}

我在这里看到了很多答案,但我没有尝试任何一个。我刚刚创建了如下代码所示的过滤器。

import org.springframework.context.annotation.Configuration;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@WebFilter(urlPatterns = "/Admin")
@Configuration
public class AdminFilter implements Filter{
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse  servletResponse, FilterChain filterChain) throws IOException, ServletException      {
    System.out.println("happened");

    }

    @Override
    public void destroy() {

    }
}

我让剩下的Spring Boot应用程序保持原样。

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 {}

}

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();
    }
}