Java: InputStream轉化為byte數組

在commons-io包中org.apache.commons.io.IOUtils類的toByteArray(InputStream input)已經有實現了,我們可以參考下思路,完成我們的方法,我們可以用類似下面的代碼實現inputStream轉化為byte[]數組

public static byte[] toByteArray(InputStream input) throws IOException {
    ByteArrayOutputStream output = new ByteArrayOutputStream();
    byte[] buffer = new byte[4096];
    int n = 0;
    while (-1 != (n = input.read(buffer))) {
        output.write(buffer, 0, n);
    }
    return output.toByteArray();
}

可利用此Api 讀取android sdcard上存儲的二進制文件內容：

  public static byte[] readBinaryFileContent(Context context, Uri uri) {
        if (context == null || uri == null) return null;
        try {
            InputStream inputStream = context.getContentResolver().openInputStream(uri);
            if (inputStream == null) return null;
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            byte buff[] = new byte[1024];
            int len = 0;
            while ((len = inputStream.read(buff)) != -1) {
                baos.write(buff, 0, len);
            }
            baos.flush();
            return baos.toByteArray();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }