官网相关案例：
https://docs.spring.io/spring-cloud-gateway/docs/current/reference/html/#the-modifyresponsebody-gatewayfilter-factoryModifyRequestBodyGatewayFilterFactory类:相关代码：
java
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.util.StrUtil;
import com.alibaba.fastjson.JSONObject;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.reactivestreams.Publisher;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.NettyWriteResponseFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.DefaultDataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.http.server.reactive.ServerHttpResponseDecorator;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import java.util.List;
/**
* @Author: meng
* @Description: 自定义返回体 - 借鉴原生类ModifyRequestBodyGatewayFilterFactory实现
* https://docs.spring.io/spring-cloud-gateway/docs/current/reference/html/#the
* -modifyresponsebody-gatewayfilter-factory
* @Date: 2023/4/18 13:37
* @Version: 1.0
*/
@Slf4j
@Component
public class ResponseGatewayFilterFactory extends AbstractGatewayFilterFactory<ResponseGatewayFilterFactory.Config> {
public ResponseGatewayFilterFactory() {
super(Config.class);
}
@Data
@AllArgsConstructor
@NoArgsConstructor
public static class Config {
// 不需要自定义的接口
List<String> pathExclude;
}
@Override
public GatewayFilter apply(Config config) {
RewriteResponseGatewayFilter rewriteResponseGatewayFilter = new RewriteResponseGatewayFilter(config);
return rewriteResponseGatewayFilter;
}
public class RewriteResponseGatewayFilter implements GatewayFilter, Ordered {
private Config config;
public RewriteResponseGatewayFilter(Config config) {
this.config = config;
}
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
// 不需要自定义的接口，直接返回
log.info("pathExclude:{}", config.pathExclude);
if (CollUtil.isNotEmpty(config.pathExclude)) {
long count = config.pathExclude.stream()
.filter(uri -> StrUtil.contains(exchange.getRequest().getPath().toString(), uri))
.count();
if (count > 0) {
return chain.filter(exchange);
}
}
String appId = exchange.getRequest().getHeaders().getFirst("X-APPID");
if (StrUtil.isBlank(appId)) {
return buildResponse(exchange, HttpStatus.UNAUTHORIZED.value(), "appId不能为空");
}
ServerHttpResponse originalResponse = exchange.getResponse();
DataBufferFactory bufferFactory = originalResponse.bufferFactory();
try {
ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
@Override
public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
if (body instanceof Flux) {
Flux<? extends DataBuffer> fluxBody = Flux.from(body);
return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
byte[] newContent = new byte[0];
try {
DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
DataBuffer join = dataBufferFactory.join(dataBuffers);
byte[] content = new byte[join.readableByteCount()];
join.read(content);
DataBufferUtils.release(join);
// 获取响应数据
String responseStr = new String(content, "UTF-8");
// 修改响应数据
JSONObject jsonObject = new JSONObject();
jsonObject.put("code", HttpStatus.UNAUTHORIZED.value());
jsonObject.put("message", "请求成功");
jsonObject.put("data", responseStr);
String message = jsonObject.toJSONString();
newContent = message.getBytes("UTF-8");
originalResponse.getHeaders().setContentLength(newContent.length);
}
catch (Exception e) {
log.error("appId:{}, responseStr exchange error:{}", appId, e);
throw new RuntimeException(e);
}
return bufferFactory.wrap(newContent);
}));
}
return super.writeWith(body);
}
@Override
public Mono<Void> writeAndFlushWith(Publisher<? extends Publisher<? extends DataBuffer>> body) {
return writeWith(Flux.from(body).flatMapSequential(p -> p));
}
};
return chain.filter(exchange.mutate().response(decoratedResponse).build());
}
catch (Exception e) {
log.error("RewriteResponse error:{}", e);
return Mono.error(new Exception("RewriteResponse fail", e));
}
}
@Override
public int getOrder() {
return NettyWriteResponseFilter.WRITE_RESPONSE_FILTER_ORDER - 2;
}
}
@SneakyThrows
public static Mono<Void> buildResponse(ServerWebExchange exchange, int code, String message) {
ServerHttpResponse response = exchange.getResponse();
response.setStatusCode(HttpStatus.OK);
response.getHeaders().add(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_UTF8_VALUE);
JSONObject jsonObject = new JSONObject();
jsonObject.put("code", code);
jsonObject.put("message", message);
jsonObject.put("data", "");
byte[] bytes = jsonObject.toJSONString().getBytes("UTF-8");
DataBuffer bodyDataBuffer = response.bufferFactory().wrap(bytes);
return response.writeWith(Mono.just(bodyDataBuffer));
}
}