1 files changed, 30 insertions, 0 deletions
diff --git a/src/main/java/com/keuin/kbackupfabric/backup/incremental/ObjectCollectionConverter.java b/src/main/java/com/keuin/kbackupfabric/backup/incremental/ObjectCollectionConverter.java
new file mode 100644
index 0000000..4e8a379
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/backup/incremental/ObjectCollectionConverter.java
@@ -0,0 +1,30 @@
+package com.keuin.kbackupfabric.backup.incremental;
+
+import com.keuin.kbackupfabric.util.backup.incremental.ObjectCollection;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Convert legacy `ObjectCollection` (keep for backward-compatibility after refactoring the code)
+ * to new `ObjectCollection2`.
+ */
+public class ObjectCollectionConverter {
+    /**
+     * Convert legacy `ObjectCollection` (keep for backward-compatibility after refactoring the code)
+     * to new `ObjectCollection2`.
+     *
+     * @param objectCollection old instance.
+     * @return new instance.
+     */
+    public static ObjectCollection2 convert(ObjectCollection objectCollection) {
+        Map<String, ObjectCollection> oldSubCollectionMap = objectCollection.getSubCollectionMap();
+        Map<String, ObjectCollection2> convertedSubCollectionMap = new HashMap<>(oldSubCollectionMap.size());
+        oldSubCollectionMap.forEach((s, c) -> convertedSubCollectionMap.put(s, convert(c)));
+        Set<ObjectElement> convertedElementSet = new HashSet<>();
+        objectCollection.getElementSet().forEach(oldElement -> convertedElementSet.add(ObjectElementConverter.convert(oldElement)));
+        return new ObjectCollection2(objectCollection.getName(), convertedElementSet, convertedSubCollectionMap);
+    }
+}