ディレクトリ/ファイルの判定メソッドを実装

source/src/main/java/one/nem/lacerta/source/file/impl/FileManagerImpl.java

@@ -78,13 +78,23 @@ public class FileManagerImpl implements FileManager {
 
     @Override
     public boolean isDirectory() {
+        if (this.isExist()) {
+            File file = this.path.toFile();
+            return file.isDirectory();
+        } else {
             return false;
         }
+    }
 
     @Override
     public boolean isFile() {
+        if (this.isExist()) {
+            File file = this.path.toFile();
+            return file.isFile();
+        } else {
             return false;
         }
+    }
 
     @Override
     public boolean isReadable() {