判断文本内容编码格式

//获取编码格式 gb2312,UTF-16,UTF-8,Unicode,UTF-8
public static String getCode(String path) throws Exception {
    InputStream inputStream = new FileInputStream(path);
    byte[] head = new byte[3];
    inputStream.read(head);
    String code = "GBK";    // 或gb2312
    if (head[0] == -1 && head[1] == -2)
        code = "UTF-16";
    else if (head[0] == -2 && head[1] == -1)
        code = "Unicode";
    else if (head[0] == -17 && head[1] == -69 && head[2] == -65)
        code = "UTF-8";
    inputStream.close();
    return code;
}