base64编码音频文件并作为String发送然后解码字符串 [英] base64 encode audio file and send as a String then decode the String

问题描述

我已经坚持这个问题几个小时了，现在试图让它运转起来。基本上我想要做的是以下内容。 Base64编码从Android设备上的SD卡中拾取的音频文件，Base64对其进行编码，将其转换为字符串，然后再次使用Base64解码字符串并将文件保存回sdcard。听起来相当简单，使用文本文件时效果很好。例如，如果我创建一个简单的文本文件，调用它dave.text并注入一些文本，说Hello Dave或类似的东西它工作得很好，但是当我尝试用二进制文件做同样的事情时失败，在这个例子中是音频。这是我正在使用的代码。

I have been stuck on this issue for a few hours now trying to get it working. Basically what I am trying to do is the following. Base64 encode an audio file picked up from an sdcard on an Android device, Base64 encode it, convert it into a String and then decode the String using Base64 again and save the file back to sdcard. It all sounds fairly simple and works great when doing it using a text file. For example if I create a simple text file, call it dave.text and inject some text it in say "Hello Dave" or something similar it works great, but fails when I try doing the same with a binary file, audio in this example. Here's the code that I am using.

File file = new File(Environment.getExternalStorageDirectory() + "/hello-4.wav");
byte[] FileBytes = FileUtils.readFileToByteArray(file);

byte[] encodedBytes = Base64.encode(FileBytes, 0);
String encodedString = new String(encodedBytes);                                        
Utilities.log("~~~~~~~~ Encoded: ", new String(encodedString));

byte[] decodedBytes = Base64.decode(encodedString, 0);
String decodedString = new String(decodedBytes);
Utilities.log("~~~~~~~~ Decoded: ", new String(decodedString));

try {
    File file2 = new File(Environment.getExternalStorageDirectory() + "/hello-5.wav");
    FileOutputStream os = new FileOutputStream(file2, true);
    os.write(decodedString.getBytes());
    os.flush();
    os.close();
} catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

此时如果我尝试保存文件，它就会损坏。音频文件hello-5.wav的大小比原始文件大，而且没有播放。

At this point if I try to save the file, it becomes corrupted. The audio file hello-5.wav is larger in size then the original and it doesn't play.

任何想法我在这里做错了什么？如果我尝试使用os.write（decodingBytes）保存decodeBytes，它可以工作但不能转换为String并使用getBytes（）。

Any ideas what I am doing wrong here? If I try to save decodedBytes using os.write(decodedBytes) it works but not when converted to a String and getBytes() is used.

有什么想法吗？谢谢！

推荐答案

你正在大量混合 String s和字节[] 秒。不要那样做。如果要将 byte [] 编码为 String ，请使用 Base64.encodeToString（） ，而不是编码为字节，然后然后创建一个字符串。

You're heavily mixing Strings and byte[]s. Don't do that. If you want to encode a byte[] to a String, use Base64.encodeToString(), instead of encoding to bytes and then creating a string.

如果我尝试使用os.write（decodingBytes）保存decodeBytes它可以工作，但是当转换为String并且没有使用getBytes（）时。

If I try to save decodedBytes using os.write(decodedBytes) it works but not when converted to a String and getBytes() is used.

调用 new String（byte []） 不能达到您的预期。

Calling new String(byte[]) does not do what you think it does.

同样使用 Base64.decode （String，int） 解码字符串。

Likewise use Base64.decode(String, int) to decode the string.

像这样（未经测试）：

File file = new File(Environment.getExternalStorageDirectory() + "/hello-4.wav");
byte[] bytes = FileUtils.readFileToByteArray(file);

String encoded = Base64.encodeToString(bytes, 0);                                       
Utilities.log("~~~~~~~~ Encoded: ", encoded);

byte[] decoded = Base64.decode(encoded, 0);
Utilities.log("~~~~~~~~ Decoded: ", Arrays.toString(decoded));

try
{
    File file2 = new File(Environment.getExternalStorageDirectory() + "/hello-5.wav");
    FileOutputStream os = new FileOutputStream(file2, true);
    os.write(decoded);
    os.close();
}
catch (Exception e)
{
    e.printStackTrace();
}

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但为什么你是base64首先编码音频文件？

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But why are you base64 encoding an audio file in the first place?

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