Add a method to return the current used database name

Signed-off-by: yhmo <yihua.mo@zilliz.com>

Author: yhmo

sdk-core/src/main/java/io/milvus/v2/client/MilvusClientV2.java

@@ -53,6 +53,7 @@
 import io.milvus.v2.utils.RpcUtils;
 import lombok.NonNull;
 import lombok.Setter;
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -85,7 +86,6 @@ public MilvusClientV2(ConnectConfig connectConfig) {
             connect(connectConfig);
 
             initServices(connectConfig.getDbName());
-
         }
     }
 
@@ -191,6 +191,14 @@ public MilvusClientV2 withTimeout(long timeout, TimeUnit timeoutUnit) {
         return this;
     }
 
+    public String currentUsedDatabase() {
+        String dbName = this.connectConfig.getDbName();
+        if (StringUtils.isEmpty(dbName)) {
+            return "default";
+        }
+        return dbName;
+    }
+
     /////////////////////////////////////////////////////////////////////////////////////////////
     // Database Operations
     /////////////////////////////////////////////////////////////////////////////////////////////