java获取文本文件的编码格式

Posted 2022-12-06 peak wang

/**
     * 获取文件的编码格式
     * @param file
     * @return
     */
    public String GetCharset(File file) 
        String charset = "GBK";
        byte[] first3Bytes = new byte[3];
        try 
            boolean checked = false;
            //BufferedInputStream bis = new BufferedInputStream(
            //new FileInputStream(file));
            //bis.mark(0);
            //int read = bis.read(first3Bytes, 0, 3);
            InputStream is = new FileInputStream(file);
            int read = is.read(first3Bytes, 0, 3);

            if (read == -1)
                return charset;
            //Log.i(TAG,"[GetCharset]first3Bytes[0]:"+first3Bytes[0]+", first3Bytes[1]:"+first3Bytes[1]+",first3Bytes[2]:"+first3Bytes[2]);
            if (first3Bytes[0] == (byte) 0xFF && first3Bytes[1] == (byte) 0xFE) 
                charset = "UTF-16LE";
                checked = true;
             else if (first3Bytes[0] == (byte) 0xFE
                    && first3Bytes[1] == (byte) 0xFF) 
                charset = "UTF-16BE";
                checked = true;
             else if (first3Bytes[0] == (byte) 0xEF
                    && first3Bytes[1] == (byte) 0xBB
                    && first3Bytes[2] == (byte) 0xBF) 
                charset = "UTF-8";
                checked = true;
            else if (first3Bytes[0] == (byte) 0xA
                    && first3Bytes[1] == (byte) 0x5B
                    && first3Bytes[2] == (byte) 0x30) 
                charset = "UTF-8";
                checked = true;
            else if (first3Bytes[0] == (byte) 0xD
                    && first3Bytes[1] == (byte) 0xA
                    && first3Bytes[2] == (byte) 0x5B) 
                charset = "GBK";
                checked = true;
            else if (first3Bytes[0] == (byte) 0x5B
                    && first3Bytes[1] == (byte) 0x54
                    && first3Bytes[2] == (byte) 0x49) 
                charset = "windows-1251";
                checked = true;
            
            //bis.reset();
            InputStream istmp = new FileInputStream(file);
            if (!checked) 
                int loc = 0;
                while ((read = istmp.read()) != -1) 
                    loc++;
                    if (read >= 0xF0)
                        break;
                    if (0x80 <= read && read <= 0xBF)
                        break;
                    if (0xC0 <= read && read <= 0xDF) 
                        read = istmp.read();
                        if (0x80 <= read && read <= 0xBF)
                            continue;
                        else
                            break;
                     else if (0xE0 <= read && read <= 0xEF) 
                        read = istmp.read();
                        if (0x80 <= read && read <= 0xBF) 
                            read = istmp.read();
                            if (0x80 <= read && read <= 0xBF) 
                                charset = "UTF-8";
                                break;
                             else
                                break;
                         else
                            break;
                    
                
            
            is.close();
            istmp.close();
         catch (Exception e) 
            e.printStackTrace();
        
        return charset;