Package org.sakaiproject.entitybroker

Class EntityReference

  • All Implemented Interfaces:
    Serializable, Cloneable
    Direct Known Subclasses:
    IdEntityReference
    public class EntityReference
extends Object
implements Cloneable, Serializable
    The class of all Entity references handled by the EntityBroker system. This provides the entity prefix, which uniquely identifies the EntityProvider responsible for handling the Entity. It optionally provides the entity id which uniquely identifies an entity locally within the prefix space. It also provides for all parsing methods for entity references (always of the form /prefix or /prefix/id)
    Author:
    Aaron Zeckoski (aaronz@vt.edu)
    See Also:
    Serialized Form

    • Field Detail

      • originalReference

        protected transient String originalReference

      • prefix

        public String prefix
        An entity prefix, should match with the prefix handled in an EntityProvider, uniquely identifies an entity space or entity type
        WARNING: use the getPrefix() method rather than referring to this directly

    • Constructor Detail

      • EntityReference

        public EntityReference()

      • EntityReference

        public EntityReference​(String reference)
        Constructor which takes an entity reference, this is the most common way to construct an entity reference object
        Parameters:
        reference - a globally unique reference to an entity, consists of the entity prefix and optional path segments

      • EntityReference

        public EntityReference​(String prefix,
                       String id)
        Convenience constructor for when you know the prefix and/or id
        Parameters:
        prefix - the entity prefix
        id - the local entity id (can be empty string if there is no id)

    • Method Detail

      • getOriginalReference

        public String getOriginalReference()
        This is a special method and should not normally be used, use toString() or getReference()
        Returns:
        the reference string used to create this object or null if this was created using a constructor which does not supply a reference

      • setOriginalReference

        protected void setOriginalReference​(String reference)

      • getPrefix

        public String getPrefix()
        Returns:
        the entity prefix (uniquely identifies an entity space or entity type), this should never be null

      • getId

        public String getId()
        A local entity id, represents an entity uniquely in a tool/webapp, could match with the actual id of a model data object, this will be null if this reference refers to an entity space only
        Returns:
        the entity id (locally unique id for an entity of this entity type) or null if this this reference refers to an entity space only

      • isEmpty

        public boolean isEmpty()
        Returns:
        true if this object contains no reference data, false if it contains a valid reference

      • makeEntityReference

        protected String makeEntityReference​(boolean spaceOnly)
        Override this if you are making a new class to define your entity reference
        Parameters:
        spaceOnly - if this is true then only return the entity space reference (e.g. /prefix), otherwise return the full reference (e.g. /prefix/id)
        Returns:
        an entity reference string

      • makeEntityPrefix

        protected String makeEntityPrefix()
        Override this if you are making a new class to define your entity reference, called by public getPrefix() method
        Returns:
        the prefix for the current entity reference

      • makeEntityId

        protected String makeEntityId()
        Override this if you are making a new class to define your entity reference, called by public getId() method
        Returns:
        the prefix for the current entity reference

      • getReference

        public String getReference()
        Get the string reference for this entity reference object, same as calling toString()
        Returns:
        the full entity reference

      • getSpaceReference

        public String getSpaceReference()
        Get the space reference for this entity reference, this ignored any id and only returns the reference to the entity space
        Returns:
        the entity space reference (e.g. /myPrefix)

      • toString

        public String toString()
        Overrides:
        toString in class Object
        Returns:
        the string version of this entity reference, example: /prefix if there is no id or /prefix/id if there is an id

      • getPrefix

        public static String getPrefix​(String reference)
        Get the entity prefix based on an entity reference string, WARNING: this is meant for internal use, use EntityReference(String) and the methods in EntityBroker to parse references
        Parameters:
        reference - an entity reference or entity URL
        Returns:
        the entity prefix

      • getIdFromRef

        public static String getIdFromRef​(String reference)
        Will convert a reference into an id (even if it is not a reference)
        Parameters:
        reference - an entity reference (e.g. /user/aaronz)
        Returns:
        the id from the reference (e.g. aaronz), preserves null

      • getIdFromRefByKey

        public static String getIdFromRefByKey​(String reference,
                                       String key)
        Get the id value out of a reference by the key that preceeds it
        Parameters:
        reference - an entity reference (e.g. /site/siteId/group/groupId)
        key - the key to get the id from (e.g. 'group' yields groupId)
        Returns:
        the id value OR null if no key is found or no id is available

      • findPrefix

        protected static String findPrefix​(String reference)
        Get the entity prefix based on an entity reference
        Parameters:
        reference - a globally unique reference to an entity, consists of the entity prefix and optional id
        Returns:
        the entity prefix

      • findId

        protected static String findId​(String reference)
        Get the local entity id based on a full entity reference
        Parameters:
        reference - a globally unique reference to an entity, consists of the entity prefix and optional id
        Returns:
        the local entity id or null if none can be found

      • getSeparatorPos

        protected static int getSeparatorPos​(String reference,
                                     int number)
        Parameters:
        reference - a globally unique reference to an entity, consists of the entity prefix and optional id
        number - this is the separator to get, 0 would return the first one found, 1 would return the second
        Returns:
        the location of the separator between the entity and the id or -1 if none found

      • checkReference

        protected static void checkReference​(String reference)
        Check if a reference is basically valid
        Parameters:
        reference -
        Throws:
        IllegalArgumentException - if the reference is not even basically valid

      • checkPrefixId

        protected static void checkPrefixId​(String prefix,
                                    String id)
        Checks this prefix and id to see if they are valid format, throw exceptions if they aren't