Package uk.ac.starlink.vo

Class UserAgentUtil

  • public class UserAgentUtil
extends java.lang.Object
    Utilities for manipulating the HTTP User-Agent header from the JVM, following IVOA usage conventions. At time of writing, these conventions are sketched in the UserAgentUsage page on the IVOA wiki; they may be amended and/or written up more formally in the future.

    Typical usage would be: 

       String uaComment = UserAgentUtil.COMMENT_VALIDATE;   // "(IVOA-validate)"
   UserAgentUtil.pushUserAgentToken( uaComment );
   ... do validation ...
   UserAgentUtil.popUserAgentToken( uaComment );
    Since:
    12 Apr 2019
    Author:
    Mark Taylor
    See Also:
    RFC 2616 sec 14.43, UserAgentUsage IVOA wiki page

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String AGENT_PROPNAME
      System property that can be used to manipulate the UserAgent header.
      static java.lang.String COMMENT_HARVEST
      Comment token indicating client performs VO harvesting.
      static java.lang.String COMMENT_MONITOR
      Comment token indicating client performs VO monitoring.
      static java.lang.String COMMENT_VALIDATE
      Comment token indicating client performs VO validation.
      static java.lang.String IVOA_PREFIX
      String prefixed to purpose verb to introduce IVOA operation comment.
      static java.lang.String PURPOSE_HARVEST
      Purpose verb indicating service harvesting: "harvest".
      static java.lang.String PURPOSE_MONITOR
      Purpose verb indicating service monitoring: "monitor".
      static java.lang.String PURPOSE_VALIDATE
      Purpose verb indicating validation: "validate".

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static java.lang.String createOpPurposeComment​(java.lang.String purpose, java.lang.String extra)
      Assembles a string of the form (IVOA-<purpose> <extra>).
      static void popUserAgentToken​(java.lang.String token)
      Removes a token/comment from the currently-used User-Agent string.
      static void pushUserAgentToken​(java.lang.String token)
      Appends a token/comment to the currently used User-Agent string.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • PURPOSE_VALIDATE

        public static final java.lang.String PURPOSE_VALIDATE
        Purpose verb indicating validation: "validate".
        See Also:
        Constant Field Values

      • PURPOSE_MONITOR

        public static final java.lang.String PURPOSE_MONITOR
        Purpose verb indicating service monitoring: "monitor".
        See Also:
        Constant Field Values

      • PURPOSE_HARVEST

        public static final java.lang.String PURPOSE_HARVEST
        Purpose verb indicating service harvesting: "harvest".
        See Also:
        Constant Field Values

      • IVOA_PREFIX

        public static final java.lang.String IVOA_PREFIX
        String prefixed to purpose verb to introduce IVOA operation comment.
        See Also:
        Constant Field Values

      • COMMENT_VALIDATE

        public static final java.lang.String COMMENT_VALIDATE
        Comment token indicating client performs VO validation.

      • COMMENT_MONITOR

        public static final java.lang.String COMMENT_MONITOR
        Comment token indicating client performs VO monitoring.

      • COMMENT_HARVEST

        public static final java.lang.String COMMENT_HARVEST
        Comment token indicating client performs VO harvesting.

      • AGENT_PROPNAME

        public static final java.lang.String AGENT_PROPNAME
        System property that can be used to manipulate the UserAgent header.
        See Also:
        Constant Field Values

    • Method Detail

      • pushUserAgentToken

        public static void pushUserAgentToken​(java.lang.String token)
        Appends a token/comment to the currently used User-Agent string. This does not overwrite existing text, which is in general useful.
        Parameters:
        token - string to add

      • popUserAgentToken

        public static void popUserAgentToken​(java.lang.String token)
        Removes a token/comment from the currently-used User-Agent string. This only has effect if the given token is at the end of the current list, that is if it has just been added. If it's not present or not at the end, a warning is logged and there is no other effect.
        Parameters:
        token - previously added string to remove

      • createOpPurposeComment

        public static java.lang.String createOpPurposeComment​(java.lang.String purpose,
                                                      java.lang.String extra)
        Assembles a string of the form (IVOA-<purpose> <extra>).
        Parameters:
        purpose - operational purpose string; recommended values are PURPOSE_* static members of this class
        extra - free form additional text excluding "(" or ")"; may be null
        Returns:
        string suitable for User-Agent header comment
        Throws:
        java.lang.IllegalArgumentException - if rudimentary syntax checking detects errors