diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/structure/HugeElement.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/structure/HugeElement.java
index cbd03d37f3..825eb73585 100644
--- a/hugegraph-core/src/main/java/com/baidu/hugegraph/structure/HugeElement.java
+++ b/hugegraph-core/src/main/java/com/baidu/hugegraph/structure/HugeElement.java
@@ -59,7 +59,7 @@
 public abstract class HugeElement implements Element, GraphType, Idfiable {
 
     private static final MutableIntObjectMap<HugeProperty<?>> EMPTY_MAP =
-                         new IntObjectHashMap<>();
+                         CollectionFactory.newIntObjectMap();
     private static final int MAX_PROPERTIES = BytesBuffer.UINT16_MAX;
 
     private final HugeGraph graph;
diff --git a/hugegraph-core/src/main/java/com/baidu/hugegraph/util/collection/SingleThreadObjectIntMapping.java b/hugegraph-core/src/main/java/com/baidu/hugegraph/util/collection/SingleThreadObjectIntMapping.java
index 4cf5d0198d..b254565adb 100644
--- a/hugegraph-core/src/main/java/com/baidu/hugegraph/util/collection/SingleThreadObjectIntMapping.java
+++ b/hugegraph-core/src/main/java/com/baidu/hugegraph/util/collection/SingleThreadObjectIntMapping.java
@@ -28,6 +28,7 @@
 public class SingleThreadObjectIntMapping<V> implements ObjectIntMapping<V> {
 
     private static final int MAGIC = 1 << 16;
+
     private final IntObjectHashMap<V> int2IdMap;
 
     public SingleThreadObjectIntMapping() {
@@ -37,19 +38,22 @@ public SingleThreadObjectIntMapping() {
     @Watched
     @SuppressWarnings("unchecked")
     public int object2Code(Object object) {
-        int key = object.hashCode();
+        int code = object.hashCode();
         // TODO: improve hash algorithm
         for (int i = 1; i > 0; i <<= 1) {
-            for (int j = 0; i >= MAGIC && j < 10; j++) {
-                Id existed = (Id) this.int2IdMap.get(key);
+            for (int j = 0; j < 10; j++) {
+                Id existed = (Id) this.int2IdMap.get(code);
                 if (existed == null) {
-                    this.int2IdMap.put(key, (V) object);
-                    return key;
+                    this.int2IdMap.put(code, (V) object);
+                    return code;
                 }
                 if (existed.equals(object)) {
-                    return key;
+                    return code;
+                }
+                code = code + i + j;
+                if (i < MAGIC) {
+                    break;
                 }
-                key = key + i + j;
             }
         }
         throw new HugeException("Failed to get code for id: %s", object);
diff --git a/hugegraph-test/src/main/java/com/baidu/hugegraph/unit/core/Int2IntsMapTest.java b/hugegraph-test/src/main/java/com/baidu/hugegraph/unit/core/Int2IntsMapTest.java
index 52b2ca1b81..cfe8abbcf3 100644
--- a/hugegraph-test/src/main/java/com/baidu/hugegraph/unit/core/Int2IntsMapTest.java
+++ b/hugegraph-test/src/main/java/com/baidu/hugegraph/unit/core/Int2IntsMapTest.java
@@ -104,11 +104,11 @@ public void testInt2IntsMap() {
                                263,264,265,266,267,268,269};
         results[4] = new int[]{270,271,272,273,274,275,276,277,278,279,
                                280,281,282,283,284,285,286,287,288,289,
-                               290, 291,292,293,294,295,296,297,298,299};
+                               290,291,292,293,294,295,296,297,298,299};
 
         for (int ii = 0; ii < 5; ii++) {
             int[] result = map.getValues(ii + 1);
-            Assert.assertTrue(Arrays.equals(results[ii], result));
+            Assert.assertArrayEquals(results[ii], result);
         }
     }