springcloud gateway设置context-path的操作

　　package com.yiche.ballast.filter;

　　import org.springframework.beans.factory.annotation.Value;

　　import org.springframework.context.annotation.Bean;

　　import org.springframework.context.annotation.Configuration;

　　import org.springframework.core.annotation.Order;

　　import org.springframework.core.io.buffer.DataBuffer;

　　import org.springframework.http.HttpStatus;

　　import org.springframework.http.server.reactive.ServerHttpRequest;

　　import org.springframework.http.server.reactive.ServerHttpResponse;

　　import org.springframework.web.server.WebFilter;

　　import reactor.core.publisher.Mono;

　　@Configuration

　　public class ApiFilter {

　　@Value("${spring.cloud.gateway.api-prefix:/gateway}")

　　private String prefix;

　　@Bean

　　@Order(-1)

　　public WebFilter apiPrefixFilter() {

　　return (exchange, chain) -> {

　　ServerHttpRequest request = exchange.getRequest();

　　String path = request.getURI().getRawPath();

　　if (!path.contains(prefix)) {

　　ServerHttpResponse response = exchange.getResponse();

　　response.setStatusCode(HttpStatus.BAD_GATEWAY);

　　DataBuffer buffer = response

　　.bufferFactory()

　　.wrap(HttpStatus.BAD_GATEWAY.getReasonPhrase().getBytes());

　　return response.writeWith(Mono.just(buffer));

　　}

　　String newPath = path.replaceFirst(prefix, "");

　　ServerHttpRequest newRequest = request.mutate().path(newPath).build();

　　return chain.filter(exchange.mutate().request(newRequest).build());

　　};

　　}

　　}