Spring Cloud Gateway 3.x 获取body中的数据鉴权

在Spring Cloud Gateway中，你可以通过定义一个全局过滤器来获取请求体中的数据并进行鉴权。以下是一个简单的示例，展示了如何在全局过滤器中读取请求体数据：

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.NettyDataBufferFactory;
import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
 
import java.nio.charset.StandardCharsets;
 
public class AuthGlobalFilter implements GlobalFilter {
 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 获取请求体
        return DataBufferUtils.join(exchange.getRequest().getBody())
                .flatMap(dataBuffer -> {
                    // 将数据缓冲区内容转换成字符串
                    byte[] bytes = new byte[dataBuffer.readableByteCount()];
                    dataBuffer.read(bytes);
                    String body = new String(bytes, StandardCharsets.UTF_8);
 
                    // 这里可以添加鉴权逻辑，例如检查body中的token
                    // boolean isAuthenticated = authenticate(body);
                    // if (!isAuthenticated) {
                    //     // 不通过鉴权，返回错误响应
                    //     return Mono.defer(() -> Mono.error(new RuntimeException("Authentication failed")));
                    // }
 
                    // 重置请求体，以便后续过滤器可以正常读取
                    DataBufferUtils.release(dataBuffer);
                    Flux<DataBuffer> cachedFlux = Flux.defer(() -> Flux.just(bufferFactory.wrap(bytes)));
                    ServerHttpRequestDecorator decorator = new ServerHttpRequestDecorator(exchange.getRequest()) {
                        @Override
                        public Flux<DataBuffer> getBody() {
                            return cachedFlux;
                        }
                    };
                    return chain.filter(exchange.mutate().request(decorator).build());
                });
    }
}

在上面