Migrated Multiverse-Adventure's copyFolder() into core.

src/main/java/com/onarandombox/MultiverseCore/utils/FileUtils.java

@@ -8,6 +8,13 @@
 package com.onarandombox.MultiverseCore.utils;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.logging.Logger;
 
 /**
  * File-utilities.
@@ -37,4 +44,57 @@ public class FileUtils {
             return false;
         }
     }
+
+    /**
+     * Helper method to copy the world-folder
+     *
+     * @returns if it had success
+     */
+    public static boolean copyFolder(File source, File target, Logger log) {
+        InputStream in = null;
+        OutputStream out = null;
+        try {
+            if (source.isDirectory()) {
+
+                if (!target.exists())
+                    target.mkdir();
+
+                String[] children = source.list();
+                // for (int i=0; i<children.length; i++) {
+                for (String child : children) {
+                    copyFolder(new File(source, child), new File(target, child), log);
+                }
+            }
+            else {
+                in = new FileInputStream(source);
+                out = new FileOutputStream(target);
+
+                byte[] buf = new byte[1024];
+                int len;
+                while ((len = in.read(buf)) > 0) {
+                    out.write(buf, 0, len);
+                }
+            }
+            return true;
+        }
+        catch (FileNotFoundException e) {
+            log.warning("Exception while copying file: " + e.getMessage());
+        }
+        catch (IOException e) {
+            log.warning("Exception while copying file: " + e.getMessage());
+        }
+        finally {
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (IOException ignore) { }
+            }
+            if (out != null) {
+                try {
+                    out.close();
+                } catch (IOException ignore) { }
+            }
+        }
+        return false;
+    }
 }