这里有一种方法可以解决这个问题，而不依赖于第三方库：

inputStream.reset();
byte[] bytes = new byte[inputStream.available()];
DataInputStream dataInputStream = new DataInputStream(inputStream);
dataInputStream.readFully(bytes);

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或者，如果你不介意使用第三方（Commons IO）：

byte[] bytes = IOUtils.toByteArray(is);

型
Guava还有助于：

byte[] bytes = ByteStreams.toByteArray(inputStream);

型

你可以像这样使用read方法：

public static byte[] readAllBytes(InputStream inputStream) throws IOException {
    final int bufLen = 1024;
    byte[] buf = new byte[bufLen];
    int readLen;
    IOException exception = null;
    try {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        while ((readLen = inputStream.read(buf, 0, bufLen)) != -1)
            outputStream.write(buf, 0, readLen);
        return outputStream.toByteArray();
    } catch (IOException e) {
        exception = e;
        throw e;
    } finally {
        if (exception == null) inputStream.close();
        else try {
            inputStream.close();
        } catch (IOException e) {
            exception.addSuppressed(e);
        }
    }
}

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