android - 是否可以使用内部存储创建和维护包含文件的文件夹结构

Question

I have studied the link below, but it doesn't answer my question. http://developer.android.com/guide/topics/data/data-storage.html#filesInternal

If the answer to the question in the title is yes. Could someone please supply a simple example creating a subfolder and adding a file to that folder? And perhaps show how to read the file back from the sub folder?

Or maybe tell me why the example below fails miserably

在将 file.mkdirs(); 更改为 file.getParentFile().mkdirs();
后现在可以使用在下面的答案中解释

public static void Test(String path, String fileName, String fileStr, Context ctx)
{

    SaveFile(path, fileName, fileStr, ctx);
    String returnFileStr = ReadFile(path, fileName, ctx);
}
public static Boolean pathExists(String path, Context ctx)
{
    Boolean result = false;
    String[] pathSeqments = path.split("/");
    String pathStr = "";
    for(int i = 0;i<pathSeqments.length;i++ )
    {
        pathStr += pathSeqments[i];
        if(!new File(ctx.getFilesDir() +"/" + pathStr).exists())
        {
            result = false;
            break;
        }
        pathStr += "/";
        result = true;
    }
    return result;
}

public static void SaveFile(String path, String fileName, String fileStr, Context ctx) {
    try {           
        File file = new File(ctx.getFilesDir() +"/" + path, fileName); //new File(ctx.getFilesDir() +"/" + path + "/" + fileName);
        file.getParentFile().mkdirs();

        FileOutputStream fOut = new FileOutputStream(file);
        OutputStreamWriter osw = new OutputStreamWriter(fOut);

        osw.write(fileStr);

        osw.flush();
        osw.close();

    } catch (IOException ioe) {
        ioe.printStackTrace();
    }
}

public static String ReadFile(String path, String fileName, Context ctx) {
    String fileStr = null;
    try {           
        if(pathExists(path, ctx))
        {
            File file = new File(ctx.getFilesDir() +"/" + path, fileName);
            FileInputStream fIn = new FileInputStream(file);

            StringWriter writer = new StringWriter();

            IOUtils.copy(fIn, writer, "UTF-8");
            fileStr = writer.toString();
        }

    } catch (IOException ioe) {
        ioe.printStackTrace();
    }
    return fileStr;
}

Answer 1

Is it possible to create and maintain a folder structure with files Using the Internal Storage

是的，使用标准的 Java I/O。

Or maybe tell me why the example below fails miserably

有才华的程序员知道如何描述症状，而不是使用“惨败”等毫无意义的短语。

也就是说，file.mkdirs(); 创建了一个目录。然后您尝试打开该目录，就好像它是一个文件一样，以便向其中写入数据。这不适用于我所知道的任何操作系统，当然也不适用于 Android。请调用 mkdirs() 来创建文件的父目录(例如，file.getParentFile().mkdirs())。

此外，切勿使用串联来创建 File 对象。使用正确的 File 构造函数。