DERObjectIdentifier(byte[] bytes) 
{
        StringBuffer    objId = new StringBuffer();
        long            value = 0;
        boolean         first = true;
        for (int i = 0; i != bytes.length; i++)
        {
            int b = bytes[i] & 0xff;
            value = value * 128 + (b & 0x7f);
            if ((b & 0x80) == 0)             // end of number reached
            {
                if (first)
                {
                    switch ((int)value / 40)
                    {
                    case 0:
                        objId.append('0');
                        break;
                    case 1:
                        objId.append('1');
                        value -= 40;
                        break;
                    default:
                        objId.append('2');
                        value -= 80;
                    }
                    first = false;
                }
                objId.append('.');
                objId.append(Long.toString(value));
                value = 0;
            }
        }
        this.identifier = objId.toString();
}

 public DERObjectIdentifier(String identifier) 
{
        for (int i = identifier.length() - 1; i  >= 0; i--)
        {
            char ch = identifier.charAt(i);
            if ('0' < = ch && ch < = '9')
            {
                continue;
            }
            if (ch == '.')
            {
                continue;
            }
            throw new IllegalArgumentException("string " + identifier + " not an OID");
        }
        this.identifier = identifier;
}

  void encode(DEROutputStream out) throws IOException 
{
        OIDTokenizer            tok = new OIDTokenizer(identifier);
        ByteArrayOutputStream   bOut = new ByteArrayOutputStream();
        DEROutputStream         dOut = new DEROutputStream(bOut);
        writeField(bOut,
                    Integer.parseInt(tok.nextToken()) * 40
                    + Integer.parseInt(tok.nextToken()));
        while (tok.hasMoreTokens())
        {
            writeField(bOut, Long.parseLong(tok.nextToken()));
        }
        dOut.close();
        byte[]  bytes = bOut.toByteArray();
        out.writeEncoded(OBJECT_IDENTIFIER, bytes);
}

 public boolean equals(Object o) 
{
        if ((o == null) || !(o instanceof DERObjectIdentifier))
        {
            return false;
        }
        return identifier.equals(((DERObjectIdentifier)o).identifier);
}

 public String getId() 
{
        return identifier;
}

 public static DERObjectIdentifier getInstance(Object obj) 
{
        if (obj == null || obj instanceof DERObjectIdentifier)
        {
            return (DERObjectIdentifier)obj;
        }
        if (obj instanceof ASN1OctetString)
        {
            return new DERObjectIdentifier(((ASN1OctetString)obj).getOctets());
        }
        if (obj instanceof ASN1TaggedObject)
        {
            return getInstance(((ASN1TaggedObject)obj).getObject());
        }
        throw new IllegalArgumentException("illegal object in getInstance: " + obj.getClass().getName());
}

return an OID from the passed in object

 public static DERObjectIdentifier getInstance(ASN1TaggedObject obj,
    boolean explicit) 
{
        return getInstance(obj.getObject());
}

return an Object Identifier from a tagged object.

 public int hashCode() 
{
        return identifier.hashCode();
}

 public String toString() 
{
        return getId();
}