Merge remote-tracking branch 'origin/master'

# Conflicts:
#	src/main/java/com/keuin/kbackupfabric/operation/backup/PrimitiveBackupMethod.java

1 files changed, 33 insertions, 0 deletions

diff --git a/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionSerializer.java b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionSerializer.java
new file mode 100644
index 0000000..6f9b792
--- /dev/null
+++ b/src/main/java/com/keuin/kbackupfabric/util/backup/incremental/ObjectCollectionSerializer.java
@@ -0,0 +1,33 @@
+package com.keuin.kbackupfabric.util.backup.incremental;
+
+import java.io.*;
+import java.util.Objects;
+
+/**
+ * Serialize and deserialize ObjectCollection from/to the disk file.
+ */
+public class ObjectCollectionSerializer {
+    public static ObjectCollection fromFile(File file) throws IOException {
+        Objects.requireNonNull(file);
+        ObjectCollection collection;
+        try (FileInputStream fileInputStream = new FileInputStream(file)) {
+            try (ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream)) {
+                collection = (ObjectCollection) objectInputStream.readObject();
+            } catch (ClassNotFoundException ignored) {
+                // this should not happen
+                return null;
+            }
+        }
+        return collection;
+    }
+
+    public static void toFile(ObjectCollection collection, File file) throws IOException {
+        Objects.requireNonNull(collection);
+        Objects.requireNonNull(file);
+        try (FileOutputStream fileOutputStream = new FileOutputStream(file)) {
+            try (ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream)) {
+                objectOutputStream.writeObject(collection);
+            }
+        }
+    }
+}