springCloud gateway 替换请求体

最新推荐文章于 2024-09-20 15:35:29 发布

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最新推荐文章于 2024-09-20 15:35:29 发布

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本文链接：https://blog.youkuaiyun.com/weixin_42331178/article/details/118974397

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该博客介绍了如何在Spring Cloud Gateway中实现过滤器，动态替换HTTP请求体。通过创建一个`GlobalFilter`，利用`ServerHttpRequestDecorator`装饰器模式，读取原始请求体，解析为JSON，添加新的属性，然后返回新的`DataBuffer`。这个过程有助于在微服务架构中统一处理和增强入站请求。

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springCloud gateway 替换请求体

/**
 * @author ：chenqiwei
 * @date ：Created in 2021/7/12 11:41
 */
@Component
public class MyFilter implements GlobalFilter {


    private final DataBufferFactory dataBufferFactory = new NettyDataBufferFactory(ByteBufAllocator.DEFAULT);

    @Autowired
    private ObjectMapper objectMapper;

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        System.out.println("123456");
        ServerHttpRequest request = exchange.getRequest();

        // 新建一个ServerHttpRequest装饰器,覆盖需要装饰的方法
        ServerHttpRequestDecorator decorator = new ServerHttpRequestDecorator(request) {

            @Override
            public Flux<DataBuffer> getBody() {
                Flux<DataBuffer> body = super.getBody();
                InputStreamHolder holder = new InputStreamHolder();
//                InputStream inputStream;
                body.subscribe(buffer -> {
                    holder.inputStream = buffer.asInputStream();
                });
                if (null != holder.inputStream) {
                    try {
                        // 解析JSON的节点
                        JsonNode jsonNode = objectMapper.readTree(holder.inputStream);
                        Assert.isTrue(jsonNode instanceof ObjectNode, "JSON格式异常");
                        ObjectNode objectNode = (ObjectNode) jsonNode;
                        // JSON节点最外层写入新的属性
                        objectNode.put("name", "网关过滤器添加");
                        DataBuffer dataBuffer = dataBufferFactory.allocateBuffer();
                        String json = objectNode.toString();
                        System.out.println("最终的JSON数据为:{}"+ json);
                        dataBuffer.write(json.getBytes(StandardCharsets.UTF_8));
                        return Flux.just(dataBuffer);
                    } catch (Exception e) {
                        throw new IllegalStateException(e);
                    }
                } else {
                    return super.getBody();
                }
            }
        };
        // 使用修改后的ServerHttpRequestDecorator重新生成一个新的ServerWebExchange
        return chain.filter(exchange.mutate().request(decorator).build());

//        return chain.filter(exchange);
    }
}