Partition key collection not allow specify partition name (#511)

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

src/main/java/io/milvus/param/ParamUtils.java

@@ -221,7 +221,12 @@ public class ParamUtils {
         }
 
         // set partition name only when there is no partition key field
-        if (!isPartitionKeyEnabled) {
+        if (isPartitionKeyEnabled) {
+            if (partitionName != null && !partitionName.isEmpty()) {
+                String msg = "Collection " + collectionName + " has partition key, not allow to specify partition name";
+                throw new ParamException(msg);
+            }
+        } else if (partitionName != null) {
             insertBuilder.setPartitionName(partitionName);
         }
 

src/main/java/io/milvus/param/dml/InsertParam.java

@@ -53,7 +53,7 @@ public class InsertParam {
      */
     public static class Builder {
         private String collectionName;
-        private String partitionName = "_default";
+        private String partitionName = "";
         private List<InsertParam.Field> fields;
         private int rowCount;