下面是我的自定义Filter类的一个例子:

package com.dawson.controller.filter;

import org.springframework.stereotype.Component;
import org.springframework.web.filter.GenericFilterBean;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


@Component
public class DawsonApiFilter extends GenericFilterBean {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        if (req.getHeader("x-dawson-nonce") == null || req.getHeader("x-dawson-signature") == null) {
            HttpServletResponse httpResponse = (HttpServletResponse) response;
            httpResponse.setContentType("application/json");
            httpResponse.sendError(HttpServletResponse.SC_BAD_REQUEST, "Required headers not specified in the request");
            return;
        }
        chain.doFilter(request, response);
    }
}

我将它添加到Spring Boot配置中，如下所示:

package com.dawson.configuration;

import com.fasterxml.jackson.datatype.hibernate5.Hibernate5Module;
import com.dawson.controller.filter.DawsonApiFilter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

@SpringBootApplication
public class ApplicationConfiguration {
    @Bean
    public FilterRegistrationBean dawsonApiFilter() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new DawsonApiFilter());

        // In case you want the filter to apply to specific URL patterns only
        registration.addUrlPatterns("/dawson/*");
        return registration;
    }
}

对于Spring Boot在我所做的任何配置类:

@Bean
public OncePerRequestFilter myFilter() {
    return new OncePerRequestFilter() {
        @Override
        protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
            AuthUser authUser = SecurityUtil.safeGet(); // applied after secutiry filters
            ...
            filterChain.doFilter(request, response);
        }
    };
}

这就是全部，不需要任何注册。参见什么是OncePerRequestFilter?

步骤1:通过实现filter接口创建一个过滤器组件。

@Component
public class PerformanceFilter implements Filter {

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

        ...
        ...
    }

}

步骤2:使用FilterRegistrationBean将这个过滤器设置为URI模式。

@Configuration
public class FilterConfig {
    @Bean
    public FilterRegistrationBean<PerformanceFilter> perfFilter() {
        FilterRegistrationBean<PerformanceFilter> registration = new FilterRegistrationBean<>();
        registration.setFilter(new PerformanceFilter());
        registration.addUrlPatterns("/*");
        return registration;
    }
}

您可以参考此链接以获得完整的应用程序。

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();
    }
}

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

    }

}

此过滤器还将帮助您允许跨源访问

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class SimpleCORSFilter implements Filter {

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

            HttpServletResponse response = (HttpServletResponse) res;
            HttpServletRequest request = (HttpServletRequest) req;
            response.setHeader("Access-Control-Allow-Origin", "*");
            response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
            response.setHeader("Access-Control-Max-Age", "20000");
            response.setHeader("Access-Control-Allow-Headers", "x-requested-with, authorization, Content-Type, Authorization, credential, X-XSRF-TOKEN");

            if("OPTIONS".equalsIgnoreCase(request.getMethod())) {
                response.setStatus(HttpServletResponse.SC_OK);
            } else {
                chain.doFilter(req, res);
            }
    }


    public void destroy() {}

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

    }

}