# Interface Xid

public interface Xid
The Xid interface is a Java mapping of the X/Open transaction identifier XID structure. This interface specifies three accessor methods to retrieve a global transaction format ID, global transaction ID, and branch qualifier. The Xid interface is used by the transaction manager and the resource managers. This interface is not visible to the application programs.

Since:
  1.4

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `MAXBQUALSIZE`
  Maximum number of bytes returned by `getBranchQualifier()`.
  `static final int`
  `MAXGTRIDSIZE`
  Maximum number of bytes returned by `getGlobalTransactionId()`.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `byte[]`
  `getBranchQualifier()`
  Obtain the transaction branch identifier part of XID as an array of bytes.
  `int`
  `getFormatId()`
  Obtain the format identifier part of the XID.
  `byte[]`
  `getGlobalTransactionId()`
  Obtain the global transaction identifier part of XID as an array of bytes.

- ## Field Details

  - ### MAXGTRIDSIZE

    static final int MAXGTRIDSIZE
    Maximum number of bytes returned by `getGlobalTransactionId()`.
    See Also:
      - Constant Field Values

  - ### MAXBQUALSIZE

    static final int MAXBQUALSIZE
    Maximum number of bytes returned by `getBranchQualifier()`.
    See Also:
      - Constant Field Values

- ## Method Details

  - ### getFormatId

    int getFormatId()
    Obtain the format identifier part of the XID.
    Returns:
      Format identifier. O means the OSI CCR format.

  - ### getGlobalTransactionId

    byte[] getGlobalTransactionId()
    Obtain the global transaction identifier part of XID as an array of bytes.
    Returns:
      Global transaction identifier.

  - ### getBranchQualifier

    byte[] getBranchQualifier()
    Obtain the transaction branch identifier part of XID as an array of bytes.
    Returns:
      Global transaction identifier.