Spring Cloud Gateway 3 全局过滤器中修改响应体案例 1

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.HttpHeaders;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
 
public class ModifyResponseBodyGlobalFilter implements GlobalFilter {
 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpResponse originalResponse = exchange.getResponse();
        DataBufferFactory bufferFactory = originalResponse.bufferFactory();
        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
            private boolean bodyWritten = false;
 
            @Override
            public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
                if (body instanceof Flux) {
                    Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>) body;
                    return super.writeWith(fluxBody.map(dataBuffer -> {
                        // 这里可以对响应体进行修改操作
                        byte[] content = new byte[dataBuffer.readableByteCount()];
                        dataBuffer.read(content);
                        DataBufferUtils.release(dataBuffer);
                        
                        // 修改content内容
                        // ...
 
                        // 将修改后的内容重新封装成DataBuffer
                        // ...
 
                        return bufferFactory.wrap(modifiedContent);
                    }));
                }
                // 否则，直接返回原有响应体
                return super.writeWith(body);
            }
        };
 
        // 将修饰后的ServerHttpResponse替换到exchange中
        return chain.filter(exchange.mutate().response(decoratedResponse).build());
    }
}

这段代码展示了如何在Spring Cloud Gateway的全局过滤器中修改响应体。它首先定义了一个\`ModifyRespon