Package com.sun.mail.imap.protocol

Class BASE64MailboxEncoder

java.lang.Object
com.sun.mail.imap.protocol.BASE64MailboxEncoder
public class BASE64MailboxEncoder extends Object
From RFC2060: 

 5.1.3.  Mailbox International Naming Convention

   By convention, international mailbox names are specified using a
   modified version of the UTF-7 encoding described in [UTF-7].  The
   purpose of these modifications is to correct the following problems
   with UTF-7:

      1) UTF-7 uses the "+" character for shifting; this conflicts with
         the common use of "+" in mailbox names, in particular USENET
         newsgroup names.

      2) UTF-7's encoding is BASE64 which uses the "/" character; this
         conflicts with the use of "/" as a popular hierarchy delimiter.

      3) UTF-7 prohibits the unencoded usage of "\"; this conflicts with
         the use of "\" as a popular hierarchy delimiter.

      4) UTF-7 prohibits the unencoded usage of "~"; this conflicts with
         the use of "~" in some servers as a home directory indicator.

      5) UTF-7 permits multiple alternate forms to represent the same
         string; in particular, printable US-ASCII chararacters can be
         represented in encoded form.

   In modified UTF-7, printable US-ASCII characters except for "&"
   represent themselves; that is, characters with octet values 0x20-0x25
   and 0x27-0x7e.  The character "&" (0x26) is represented by the two-
   octet sequence "&-".

   All other characters (octet values 0x00-0x1f, 0x7f-0xff, and all
   Unicode 16-bit octets) are represented in modified BASE64, with a
   further modification from [UTF-7] that "," is used instead of "/".
   Modified BASE64 MUST NOT be used to represent any printing US-ASCII
   character which can represent itself.

   "&" is used to shift to modified BASE64 and "-" to shift back to US-
   ASCII.  All names start in US-ASCII, and MUST end in US-ASCII (that
   is, a name that ends with a Unicode 16-bit octet MUST end with a "-
   ").

   For example, here is a mailbox name which mixes English, Japanese,
   and Chinese text: ~peter/mail/&ZeVnLIqe-/&U,BTFw-
This class will do the correct Encoding for the IMAP mailboxes.

  • Constructor Details

    • BASE64MailboxEncoder

      public BASE64MailboxEncoder(Writer what)
      Create a BASE64 encoder
      Parameters:
      what - where to write the encoded name

  • Method Details

    • encode

      public static String encode(String original)

    • write

      public void write(int c)

    • flush

      public void flush()