如何在Android的“我的文件/内部存储/文档”文件夹中写入.txt文件？

Question

我试图使用此代码，但是什么也没发生。

    String content = "hello";
    File file;
    FileOutputStream oustrong texttputStream;
    try {
        file = new File(Environment.getExternalStorageDirectory(),"MyCache.txt");
        outputStream = new FileOutputStream(file);
        outputStream.write(content.getBytes());
        outputStream.close();
        Toast.makeText(this,"Successss ...", Toast.LENGTH_SHORT).show();
    } 
    catch (IOException e) {
        e.printStackTrace();
    }