fix: credential sign

Author: volc-sdk-team

volcengine-java-sdk-core/src/main/java/com/volcengine/ApiClient.java

@@ -1275,7 +1275,7 @@ public Request buildRequest(String path, String method, List<Pair> queryParams,
         //sign
         final Buffer buffer = new Buffer();
         try {
-            if(reqBody != null) {
+            if (reqBody != null) {
                 reqBody.writeTo(buffer);
             }
         } catch (IOException e) {
@@ -1399,8 +1399,10 @@ public void updateParamsForAuth(String[] authNames, List<Pair> queryParams, Map<
                 if (StringUtils.isEmpty(volcengineSign.getRegion())) {
                     throw new RuntimeException("Region must set when ApiClient init");
                 }
-                volcengineSign.setMethod(serviceInfo.getMethod().toUpperCase());
-                volcengineSign.setService(serviceInfo.getServiceName());
+                VolcstackSign requestSign = volcengineSign.copy();
+                requestSign.setMethod(serviceInfo.getMethod().toUpperCase());
+                requestSign.setService(serviceInfo.getServiceName());
+                auth = requestSign;
             }
             auth.applyToParams(queryParams, headerParams, payload);
         }

volcengine-java-sdk-core/src/main/java/com/volcengine/sign/VolcstackSign.java

@@ -299,5 +299,14 @@ private String signStringEncoder(String source) {
 
         return buf.toString();
     }
+
+    public VolcstackSign copy() {
+        VolcstackSign copySign = new VolcstackSign();
+        copySign.setRegion(this.region);
+        copySign.setCredentials(this.credentials);
+        copySign.setService(this.service);
+        copySign.setMethod(this.method);
+        return copySign;
+    }
 }