gataway断言源码剖析

public class CookieRoutePredicateFactory
        extends AbstractRoutePredicateFactory<CookieRoutePredicateFactory.Config> {
    /**
     * Name key.
     */
    public static final String NAME_KEY = "name";
    /**
     * Regexp key.
     */
    public static final String REGEXP_KEY = "regexp";
    public CookieRoutePredicateFactory() {
        super(Config.class);
    }
    /*
      通过shortcutFieldOrder方法设置Config配置类中的属性,需要根据具体的规则来设置
      通过shortcutType方法获取具体规则，具体参看：org.springframework.cloud.gateway.support.ShortcutConfigurable.ShortcutType
      规则包括以下几种：
        DEFAULT : 按照shortcutFieldOrder顺序依次赋值
    */
    @Override
    public List<String> shortcutFieldOrder() {
        return Arrays.asList(NAME_KEY, REGEXP_KEY);
    }
    @Override
    public Predicate<ServerWebExchange> apply(Config config) {
        return new GatewayPredicate() {
            @Override
            public boolean test(ServerWebExchange exchange) {
                List<HttpCookie> cookies = exchange.getRequest().getCookies()
                        .get(config.name);
                if (cookies == null) {
                    return false;
                }
                for (HttpCookie cookie : cookies) {
                    if (cookie.getValue().matches(config.regexp)) {
                        return true;
                    }
                }
                return false;
            }
            @Override
            public String toString() {
                return String.format("Cookie: name=%s regexp=%s", config.name,
                        config.regexp);
            }
        };
    }
    /*
     内部配置类是用来接收在配置文件中配置的参数的
      routes:
        #唯一标识符
        - id: hailtaxi-driver
          uri: lb://hailtaxi-driver
          #路由断言
          predicates:
            - Cookie=username,itheima
    */
    @Validated
    public static class Config {
        @NotEmpty
        private String name;
        @NotEmpty
        private String regexp;
        public String getName() {
            return name;
        }
        public Config setName(String name) {
            this.name = name;
            return this;
        }
        public String getRegexp() {
            return regexp;
        }
        public Config setRegexp(String regexp) {
            this.regexp = regexp;
            return this;
        }
    }
}

gateway:
      #路由配置
      routes:
        #唯一标识符
        - id: hailtaxi-driver
          uri: lb://hailtaxi-driver
          #路由断言
          predicates:
            # 自定义一个Token断言,如果请求包含Authorization的token信息则通过
            - Token=Authorization

@Slf4j
@Component // 要交给spring容器管理
public class TokenRoutePredicateFactory extends AbstractRoutePredicateFactory<TokenRoutePredicateFactory.Config> {
    public TokenRoutePredicateFactory() {
        super(Config.class);
    }
    public Predicate<ServerWebExchange> apply(Config config) {
        return exchange -> {
            // 打印配置文件参数值
            String headerName = config.getHeaderName();
            HttpHeaders headers = exchange.getRequest().getHeaders();
            List<String> header = headers.get(headerName);
            log.info("Token Predicate headers:{}", header);
            // 断言返回的是boolean值
            return header!=null && header.size()>0;
        };
    }
    @Override
    public List<String> shortcutFieldOrder() {
        return Arrays.asList("headerName");//指定配置文件中加载到的配置信息应填充到Config的哪个属性上
    }
    @Override
    public ShortcutType shortcutType() {
        return ShortcutType.DEFAULT;
    }
    @Data
    public static class Config { //static class
        private String headerName;//存储从配置文件中加载的配置
    }
}