#fixed code
                             private void getFolderView(String folderId) throws Exception {
		try {
			currentView = FileSystemManager.getInstance().getFolderView(folderId);
			if(currentView!=null && currentView.getCurrent()!=null) {
				filesTable.updateValues(currentView.getFolders(), currentView.getFiles());
				window.setTitle("kiftd-" + currentView.getCurrent().getFolderName());
			}else {
				//浏览一个不存在的文件夹时自动返回根目录
				getFolderView("root");
			}
		} catch (Exception e) {
			throw e;
		}
	}
#vulnerable code 
                             private void getFolderView(String folderId) throws Exception {
		try {
			currentView = FileSystemManager.getInstance().getFolderView(folderId);
			filesTable.updateValues(currentView.getFolders(), currentView.getFiles());
			window.setTitle("kiftd-" + currentView.getCurrent().getFolderName());
		} catch (Exception e) {
			throw e;
		}
	} 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE