Spring Gateway 对请求体和响应体进行修改

请求体修改

使用 GlobalFilter 过滤所有请求，用 ModifyRequestBodyGatewayFilterFactory 生成的 filter 通过 RewriteFunction 修改请求体。

源码

@Component
@Order(10)
public class RequestBodyModifyFilter implements GlobalFilter{
    @Resource
    private ModifyRequestBodyGatewayFilterFactory modifyRequestBodyGatewayFilterFactory;

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        return reqBodyRewriter().filter(exchange, chain);
    }

    /**
     * 修改请求体的filter
     */
    @Bean
    private GatewayFilter reqBodyRewriter(){
        return modifyRequestBodyGatewayFilterFactory.apply(new ModifyRequestBodyGatewayFilterFactory.Config().setRewriteFunction(
                String.class, String.class, rewriteFunction()
        ));
    }

    /**
     * 此处是对原请求体的修改方法
     */
    private RewriteFunction<String, String> rewriteFunction(){
        return (serverWebExchange, s) -> {
            //对请求体进行操作、s为原请求体
            return Mono.just("修改后的结果");
        };
    }
}

响应体修改

同上，通过 RewriteFunction 修改请求体。

源码

@Component
public class SM2ResponseBodyEncryptFilter implements GlobalFilter, Ordered {
    @Resource
    private ModifyResponseBodyGatewayFilterFactory modifyResponseBodyGatewayFilterFactory;

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        return resBodyRewriter().filter(exchange, chain);
    }


    /**
     * 修改请求体的filter
     */
    @Bean
    private GatewayFilter resBodyRewriter() {
        return modifyResponseBodyGatewayFilterFactory.apply(new ModifyResponseBodyGatewayFilterFactory.Config().setRewriteFunction(
                String.class, String.class, rewriteFunction()
        ));
    }

    /**
     * 响应体修改方法
     */
    private RewriteFunction<String, String> rewriteFunction() {
        return (serverWebExchange, s) -> {
            //此处对响应体进行修改、s为原响应体
            return Mono.just("修改后的响应体");
        };
    }

    /**
     * 此处为必须配置！！！否则RewriteFunction不会生效！
     * 引用自 <a href="https://gist.github.com/gatspy/a5cc3b26e9ada5c492e2b71689dd62b4">...</a>
     */
    @Override
    public int getOrder() {
        return -2; //-1 is response write filter, call before that
    }
}

Ordered

响应体执行 write 的过滤器 order 为 -1，所以必须要在执行 write 前执行修改响应体的方法。