Class MessageSet

java.lang.Object
com.chilkatsoft.chilkat2.ChilkatObject
com.chilkatsoft.chilkat2.MessageSet
All Implemented Interfaces:
AutoCloseable

public class MessageSet extends ChilkatObject
<section class="messageset-summary">

Represent and pass sets of IMAP message identifiers.

Chilkat.MessageSet represents a set of IMAP message identifiers used by Chilkat.Imap. It is a helper object for passing groups of messages to IMAP methods and for receiving groups of message IDs returned by IMAP search, fetch, copy, delete, or flag-related operations. A MessageSet may contain either UIDs or sequence numbers, and the HasUids setting identifies which form is being used.

IMAP message IDs

Store the identifiers used by IMAP operations, either as message UIDs or as sequence numbers.

Used by Chilkat.Imap

Pass message sets to IMAP methods that operate on multiple messages, or receive them from IMAP methods that return matching messages.

UID awareness

Use HasUids to indicate whether the contained identifiers are stable IMAP UIDs or mailbox-relative sequence numbers.

Add and remove IDs

Insert message identifiers, remove identifiers, check whether an ID is present, and build the exact message group needed for an IMAP operation.

Compact string formats

Load or emit compact IMAP-style message ranges such as comma-separated lists and range expressions.

Set operations

Subtract one message set from another when application logic needs to exclude already-processed or unwanted messages.

Common pattern: Use MessageSet only for IMAP message identifiers, not as a general-purpose collection. Obtain a message set from an IMAP search or build one manually, confirm whether it contains UIDs or sequence numbers, then pass it to the appropriate Chilkat.Imap method for fetching, copying, deleting, flagging, or otherwise processing the selected messages.

For an extended overview, see MessageSet Class Overview.

</section>

Instances hold a native Chilkat object: close them with ChilkatObject.close() (try-with-resources) when done; an unclosed instance is freed when it becomes unreachable.

See Also:
Online reference
  • Constructor Details

    • MessageSet

      public MessageSet()
      Creates a new MessageSet object.
  • Method Details

    • getCount

      public int getCount()
      Returns the number of unique message identifiers currently stored in the set. A newly created MessageSet has a count of 0.

      The identifiers are maintained in ascending numeric order. They are interpreted as UIDs when getHasUids() is true, or as sequence numbers when it is false.

      Returns:
      the value of the Count property (read-only)
    • getHasUids

      public boolean getHasUids()
      Indicates how the numeric identifiers in this message set are interpreted:
      • true — the values are IMAP UIDs. This is the default.
      • false — the values are mailbox-relative sequence numbers.

      Changing this property only changes how the existing numeric values are interpreted. It does not convert, validate, reorder, or clear the identifiers.

      An IMAP UID is stable only within its mailbox and while that mailbox's UIDVALIDITY remains unchanged. Sequence numbers are temporary and can change when messages are added or expunged.

      Set this property consistently before passing a manually constructed message set to an Imap method. The string formats produced by toCommaSeparatedStr() and toCompactString() contain only the numeric values and do not include this setting.

      Returns:
      the value of the HasUids property
    • setHasUids

      public void setHasUids​(boolean value)
      Sets the HasUids property; see getHasUids().
      Parameters:
      value - the new value
    • containsId

      public boolean containsId​(long msgId)
      Returns true if the raw numeric value in msgId is present in the message set; otherwise, returns false.

      The comparison is numeric only. The getHasUids() setting does not participate in the comparison.

      Parameters:
      msgId - the msgId argument (0 .. 4294967295)
      Returns:
      the result; this method never throws ChilkatException
    • fromCompactString

      public void fromCompactString​(String str)
      Clears the identifiers currently stored in this object and loads the compact message-set representation in str. The existing getHasUids() setting is preserved.

      Important: The existing set is cleared before str is parsed. If parsing fails, the message set remains empty.

      An empty string succeeds and leaves the set empty. Valid identifiers are unsigned 32-bit decimal values from 1 through 4294967295. The value 0 is not accepted. Values too large for an unsigned 32-bit integer cause the method to fail.

      The syntax uses commas to separate values or ranges, and a colon to specify an inclusive ascending range. A single range may contain at most 500,001 identifiers; equivalently, the ending value minus the starting value cannot exceed 500000.

      Version note: The error-handling behavior described here was added in Chilkat version 11.6.0.

      Input Result

      1,2,3,4,5 Loads 1,2,3,4,5.

      1:5 Loads the inclusive range 1 through 5.

      1:5,8:10 Loads 1,2,3,4,5,8,9,10.

      1,1,2,2,3 Loads the unique values 1,2,3.

      1:5,3:7 Loads the unique values 1 through 7.

      1,,3 Empty comma-separated elements are ignored; loads 1,3.

      1,2,abc,4 Unrecognized elements are ignored; loads 1,2,4.

      +1 A leading plus sign is accepted; loads 1.

      Whitespace is accepted around values, commas, and colons. This includes spaces, tabs, carriage returns, and line feeds. Empty comma-separated elements and unrecognized non-numeric elements are intentionally ignored. If str is nonempty and no valid identifier is loaded, the method returns false.

      Descending ranges, ranges containing 0, wildcard ranges such as 1:*, malformed range syntax, oversized ranges, and numeric overflow cause the method to return false.

      On success, duplicate identifiers are removed and the resulting identifiers are stored in ascending numeric order. The serialized form contains only the numbers and does not indicate whether they are UIDs or sequence numbers.

      Use toCompactString() to generate the canonical compact representation.

      Parameters:
      str - the str argument (not null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why
    • getId

      public long getId​(int index)
      Returns the message identifier at the zero-based index specified by index. Identifiers are returned in ascending numeric order.

      If index is negative or is greater than or equal to getCount(), this method returns 0xFFFFFFFF.

      Important: The numeric value 0xFFFFFFFF can also be stored in the set. Check index against Count before calling this method when that value could be present.

      Parameters:
      index - the index argument
      Returns:
      the result (see ChilkatObject.getLastMethodSuccess() where the description mentions failure)
    • insertId

      public void insertId​(long id)
      Adds id to the message set and maintains the identifiers in ascending numeric order.
      • If id is already present, no duplicate is added.
      • If id is 0, the set is unchanged.
      • The value 0xFFFFFFFF is accepted.

      The getHasUids() setting determines whether the stored values are interpreted as UIDs or sequence numbers.

      Parameters:
      id - the id argument (0 .. 4294967295)
    • removeId

      public void removeId​(long id)
      Removes the identifier whose raw numeric value equals id. If the value is not present, the set is unchanged.

      The comparison is numeric only and does not depend on getHasUids(). The remaining identifiers stay in ascending numeric order.

      Parameters:
      id - the id argument (0 .. 4294967295)
    • subtract

      public void subtract​(MessageSet msgSet)
      Removes from this message set every identifier whose raw numeric value is present in msgSet. Values not present in this set are ignored.

      The comparison is numeric only; the getHasUids() values of the two objects are not compared. This object's HasUids value is preserved, and the remaining identifiers stay in ascending numeric order.

      Passing the same object as msgSet clears the set. Passing an empty set leaves this set unchanged.

      For meaningful IMAP results, both objects should represent identifiers of the same type and from the same mailbox.

      Parameters:
      msgSet - the msgSet argument (not null)
    • toCommaSeparatedStr

      public String toCommaSeparatedStr()
      Returns the unique identifiers as a comma-separated string in ascending numeric order. An empty set returns an empty string.

      For example, a set containing the identifiers 1 through 5 returns 1,2,3,4,5.

      The returned string contains only the numeric values; it does not include the getHasUids() setting.

      Returns:
      the result (never null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why
    • toCompactString

      public String toCompactString()
      Returns the unique identifiers in ascending numeric order using compact IMAP message-set syntax. Consecutive identifiers are represented as an inclusive range. An empty set returns an empty string.

      Comma-separated form Compact form

      1,2,3,4,5 1:5

      1,2,3,4,5,8,9,10 1:5,8:10

      1,3,4,5,8,9,10 1,3:5,8:10

      The returned string is canonical for the current set: identifiers are unique, sorted, and consecutive runs are compacted. It contains only the numeric values and does not include the getHasUids() setting.

      Use fromCompactString(String) to load this format.

      Returns:
      the result (never null)
      Throws:
      ChilkatException - if the operation fails; ChilkatException.getLastErrorText() says why