gatewayFilter2 code example

Example: gatewayFilter2

package com.woolha.springcloudgateway.filter;    import org.apache.commons.lang.RandomStringUtils;  import org.springframework.cloud.gateway.filter.GatewayFilter;  import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;  import org.springframework.http.HttpStatus;  import org.springframework.http.server.reactive.ServerHttpRequest;  import org.springframework.http.server.reactive.ServerHttpResponse;  import org.springframework.stereotype.Component;  import org.springframework.web.server.ServerWebExchange;  import reactor.core.publisher.Mono;    import java.util.List;    @Component  public class MyFilter extends AbstractGatewayFilterFactory<MyFilter.Config> {      public MyFilter() {          super(Config.class);      }        private boolean isAuthorizationValid(String authorizationHeader) {          boolean isValid = true;            // Logic for checking the value            return isValid;      }        private Mono<Void> onError(ServerWebExchange exchange, String err, HttpStatus httpStatus)  {          ServerHttpResponse response = exchange.getResponse();          response.setStatusCode(httpStatus);            return response.setComplete();      }        @Override      public GatewayFilter apply(Config config) {          return (exchange, chain) -> {              ServerHttpRequest request = exchange.getRequest();                if (!request.getHeaders().containsKey("Authorization")) {                  return this.onError(exchange, "No Authorization header", HttpStatus.UNAUTHORIZED);              };                String authorizationHeader = request.getHeaders().get("Authorization").get(0);                if (!this.isAuthorizationValid(authorizationHeader)) {                  return this.onError(exchange, "Invalid Authorization header", HttpStatus.UNAUTHORIZED);              }                ServerHttpRequest modifiedRequest = exchange.getRequest().mutate().                      header("secret", RandomStringUtils.random(10)).                      build();                return chain.filter(exchange.mutate().request(modifiedRequest).build());          };      }        public static class Config {          // Put the configuration properties      }  }