SpringCloud-Gateway中自定义filter过滤器

自定义全局Filter

步骤：新建MyGlobalFilter类并实现GlobalFilter，Order两个接口

例如：自定义统计接口调用耗时的全局过滤器

import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
@Slf4j
public class MyGlobalFilter implements GlobalFilter, Ordered
{

    /**
     * 数字越小优先级越高
     * @return
     */
    @Override
    public int getOrder()
    {
        return 0;
    }

    private static final String BEGIN_VISIT_TIME = "begin_visit_time";//开始访问时间
    /**
     *第2版，各种统计
     * @param exchange
     * @param chain
     * @return
     */
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //先记录下访问接口的开始时间
        exchange.getAttributes().put(BEGIN_VISIT_TIME, System.currentTimeMillis());

        return chain.filter(exchange).then(Mono.fromRunnable(()->{
            Long beginVisitTime = exchange.getAttribute(BEGIN_VISIT_TIME);
            if (beginVisitTime != null){
                log.info("访问接口主机: " + exchange.getRequest().getURI().getHost());
                log.info("访问接口端口: " + exchange.getRequest().getURI().getPort());
                log.info("访问接口URL: " + exchange.getRequest().getURI().getPath());
                log.info("访问接口URL参数: " + exchange.getRequest().getURI().getRawQuery());
                log.info("访问接口时长: " + (System.currentTimeMillis() - beginVisitTime) + "ms");
                log.info("我是美丽分割线: ###################################################");
                System.out.println();
            }
        }));
    }
}

自定义单一内置过滤器GatewayFilter

例如：自定义一个过滤器，要求请求参数必须包含一个名为”test”的key

第一步：新建类名

注意：类名必须以GatewayFilterFactory结尾，并继承AbstractGatewayFilterFactory抽象类，例如：

@Component
public class MyGatewayFilterFactory extends AbstractGatewayFilterFactory<MyGatewayFilterFactory.Config>
{
}

第二步：自定义xxxGatewayFilterFactory.Config的静态内部类

@Component
public class MyGatewayFilterFactory extends AbstractGatewayFilterFactory<MyGatewayFilterFactory.Config>
{
    public static class Config {
        @Setter @Getter
        private String status;
    }
}

第三步：重写apply方法

@Override
    public GatewayFilter apply(MyGatewayFilterFactory.Config config)
    {
        return new GatewayFilter() {
            @Override
            public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
                ServerHttpRequest request =  exchange.getRequest();
                System.out.println("进入自定义网关过滤器MyGatewayFilterFactory，status===="+config.getStatus());
                if(request.getQueryParams().containsKey("atguigu")) {
                    return chain.filter(exchange);
                }else {
                    exchange.getResponse().setStatusCode(HttpStatus.BAD_REQUEST);
                    return exchange.getResponse().setComplete();
                }
            }
        };
    }

第四步：创建空参构造方法，内部调用super()方法

public MyGatewayFilterFactory() {
    super(MyGatewayFilterFactory.Config.class);
}

第五步：实现shortcutFieldOrder方法，添加对简写格式的支持

@Override
public List<String> shortcutFieldOrder() {
    List<String> list = new ArrayList<String>();
    list.add("status");
    return list;
}

完整代码

import lombok.Getter;
import lombok.Setter;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.cloud.gateway.filter.factory.SetPathGatewayFilterFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.Arrays;
import java.util.List;

@Component
public class MyGatewayFilterFactory extends AbstractGatewayFilterFactory<MyGatewayFilterFactory.Config>
{
    public MyGatewayFilterFactory()
    {
        super(MyGatewayFilterFactory.Config.class);
    }


    @Override
    public GatewayFilter apply(MyGatewayFilterFactory.Config config)
    {
        return new GatewayFilter()
        {
            @Override
            public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain)
            {
                ServerHttpRequest request = exchange.getRequest();
                System.out.println("进入了自定义网关过滤器MyGatewayFilterFactory，status："+config.getStatus());
                if(request.getQueryParams().containsKey("test")){
                    return chain.filter(exchange);
                }else{
                    exchange.getResponse().setStatusCode(HttpStatus.BAD_REQUEST);
                    return exchange.getResponse().setComplete();
                }
            }
        };
    }

    @Override
    public List<String> shortcutFieldOrder() {
        return Arrays.asList("status");
    }

    public static class Config
    {
        @Getter@Setter
        private String status;//设定一个状态值/标志位，它等于多少，匹配和才可以访问
    }
}