Incremental backup now works (tested, but not thoroughly)

1 files changed, 36 insertions, 2 deletions

diff --git a/src/main/java/com/keuin/kbackupfabric/util/FilesystemUtil.java b/src/main/java/com/keuin/kbackupfabric/util/FilesystemUtil.java
index 7f74725..f245cff 100644
--- a/src/main/java/com/keuin/kbackupfabric/util/FilesystemUtil.java
+++ b/src/main/java/com/keuin/kbackupfabric/util/FilesystemUtil.java
@@ -1,6 +1,9 @@
 package com.keuin.kbackupfabric.util;
 
 import java.io.File;
+import java.io.IOException;
+
+import static org.apache.commons.io.FileUtils.forceDelete;
 
 public class FilesystemUtil {
 
@@ -22,12 +25,43 @@ public class FilesystemUtil {
 
     public static long getFileSizeBytes(String filePath) {
         long fileSize = -1;
-        try{
+        try {
             File backupZipFile = new File(filePath);
             fileSize = backupZipFile.length();
-        } catch (SecurityException ignored){
+        } catch (SecurityException ignored) {
         }
         return fileSize;
     }
 
+    public static boolean forceDeleteDirectory(File levelDirFile) throws IOException {
+        int failedCounter = 0;
+        final int MAX_RETRY_TIMES = 20;
+        IOException exception = null;
+        while (failedCounter < MAX_RETRY_TIMES) {
+            System.gc();
+            if (!levelDirFile.delete() && levelDirFile.exists()) {
+                System.gc();
+                try {
+                    forceDelete(levelDirFile); // Try to force delete.
+                } catch (IOException e) {
+                    exception = e;
+                }
+            }
+            if (!levelDirFile.exists())
+                break;
+            ++failedCounter;
+            try {
+                Thread.sleep(500);
+            } catch (InterruptedException ignored) {
+            }
+        }
+        if (exception != null)
+            throw exception;
+        if (levelDirFile.exists()) {
+            PrintUtil.error(String.format("Cannot restore: failed to delete old level %s .", levelDirFile.getName()));
+            return false;
+        }
+        return true;
+    }
+
 }