Java 生成的csv文件为0k，不报错，求指导。?报错

Java 生成的csv文件为0k,,

public static boolean genCsv(String csvPath, List<String> dataList) {
		{
			try {
				FileWriter fw = new FileWriter(csvPath);
				for (int i = 0; i < dataList.size(); i++) {
					StringBuffer str = new StringBuffer();
					System.out.println("*dataList.get(i)---"+dataList.get(i));
					 str.append(dataList.get(i) +"\r");
					fw.write(str.toString());
					fw.flush();
				 }
				fw.close();
			} catch (IOException e) {
				e.printStackTrace();
				return false;
			}
		}
		return true;
	}