Spring Cloud Gateway 修改响应数据

在Spring Cloud Gateway中，修改响应数据可以通过定义一个全局过滤器来实现。以下是一个简单的示例，展示了如何创建一个全局过滤器来修改响应体：

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
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.nio.charset.StandardCharsets;
 
@Component
public class ModifyResponseGlobalFilter implements GlobalFilter {
 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpResponse originalResponse = exchange.getResponse();
        
        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
            @Override
            public Mono<Void> writeWith(Flux<? extends DataBuffer> body) {
                if (getDelegate().isCommitted()) {
                    return super.writeWith(body);
                }
                
                return DataBufferUtils.join(body)
                        .flatMap(dataBuffer -> {
                            byte[] content = new byte[dataBuffer.readableByteCount()];
                            dataBuffer.read(content);
                            DataBufferUtils.release(dataBuffer);
 
                            // 修改响应体内容
                            String responseBody = new String(content, StandardCharsets.UTF_8);
                            String modifiedBody = modifyResponseBody(responseBody);
                            byte[] modifiedContent = modifiedBody.getBytes(StandardCharsets.UTF_8);
 
                            // 使用修改后的数据创建新的数据缓冲区
                            DataBuffer modifiedDataBuffer = originalResponse.bufferFactory().wrap(modifiedContent);
                            return super.writeWith(Flux.just(modifiedDataBuffer));
                        });
            }
        };
 
        // 将修改后的响应替换到当前的ServerWebExchange中
        return chain.filter(exchange.mutate().response(decoratedRe