fix: 修复概率性返回 503 的问题

src/main/java/com/ywt/gateway/filter/AuthGatewayFilterFactory.java

@@ -127,16 +127,6 @@ public class AuthGatewayFilterFactory extends AbstractGatewayFilterFactory<HostL
                     logger.warn("Could not get local address!");
                 }
             }
-            // 获取 request body
-            AtomicReference<String> requestBody = new AtomicReference<>("");
-            // 复用现成的 decorator
-            RecorderServerHttpRequestDecorator requestDecorator = new RecorderServerHttpRequestDecorator(request);
-            Flux<DataBuffer> body = requestDecorator.getBody();
-            body.subscribe(buffer -> {
-                CharBuffer charBuffer = StandardCharsets.UTF_8.decode(buffer.asByteBuffer());
-                requestBody.set(charBuffer.toString());
-            });
-            String bodyStr = requestBody.get();
             try {
                 String auth = config.getAuth();
                 String protocol = config.getProtocol();
@@ -249,6 +239,17 @@ public class AuthGatewayFilterFactory extends AbstractGatewayFilterFactory<HostL
                             //判断是否需要验证checksum
                             if (appInfo.isChecksum()) {
                                 String checksum = (String) payload.getClaim(KEY_CHECKSUM);
+                                // FIXME: the following code snippet may have issues with `java.lang.IllegalStateException: Rejecting additional inbound receiver.`
+                                // 获取 request body
+                                AtomicReference<String> requestBody = new AtomicReference<>("");
+                                // 复用现成的 decorator
+                                RecorderServerHttpRequestDecorator requestDecorator = new RecorderServerHttpRequestDecorator(request);
+                                Flux<DataBuffer> body = requestDecorator.getBody();
+                                body.subscribe(buffer -> {
+                                    CharBuffer charBuffer = StandardCharsets.UTF_8.decode(buffer.asByteBuffer());
+                                    requestBody.set(charBuffer.toString());
+                                });
+                                String bodyStr = requestBody.get();
                                 if (!DigestUtil.md5Hex(bodyStr).equals(checksum)) {
                                     throw new HttpMsgException(HttpStatus.INTERNAL_SERVER_ERROR, HTTP_STATUS_CODE_601,
                                             "Checksum Error");