EntityReference (Sakai Entity Broker API 21.5 API)

java.lang.Object
- org.sakaiproject.entitybroker.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 Summary

Fields
Modifier and Type	Field and Description
`protected String`	`originalReference`
`static char`	`PERIOD`
`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
`static char`	`SEPARATOR`
`static long`	`serialVersionUID`

Constructor Summary

Constructors
Constructor and Description
`EntityReference()`
`EntityReference(String reference)` Constructor which takes an entity reference, this is the most common way to construct an entity reference object
`EntityReference(String prefix, String id)` Convenience constructor for when you know the prefix and/or id

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`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
`protected static void`	`checkReference(String reference)` Check if a reference is basically valid
`protected Object`	`clone()`
`EntityReference`	`copy()`
`static EntityReference`	`copy(EntityReference ref)` Creates a copy of an entity reference
`protected static String`	`findId(String reference)` Get the local entity id based on a full entity reference
`protected static String`	`findPrefix(String reference)` Get the entity prefix based on an entity reference
`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
`static String`	`getIdFromRef(String reference)` Will convert a reference into an id (even if it is not a reference)
`static String`	`getIdFromRefByKey(String reference, String key)` Get the id value out of a reference by the key that preceeds it
`String`	`getOriginalReference()` This is a special method and should not normally be used, use `toString()` or `getReference()`
`String`	`getPrefix()`
`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
`String`	`getReference()` Get the string reference for this entity reference object, same as calling `toString()`
`protected static int`	`getSeparatorPos(String reference, int number)`
`String`	`getSpaceReference()` Get the space reference for this entity reference, this ignored any id and only returns the reference to the entity space
`boolean`	`isEmpty()`
`protected String`	`makeEntityId()` Override this if you are making a new class to define your entity reference, called by public `getId()` method
`protected String`	`makeEntityPrefix()` Override this if you are making a new class to define your entity reference, called by public `getPrefix()` method
`protected String`	`makeEntityReference(boolean spaceOnly)` Override this if you are making a new class to define your entity reference
`protected void`	`setOriginalReference(String reference)`
`String`	`toString()`

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - serialVersionUID
```
public static final long serialVersionUID
```
    See Also:
    
    Constant Field Values
  - SEPARATOR
```
public static final transient char SEPARATOR
```
    See Also:
    
    Constant Field Values
  - PERIOD
```
public static final transient char PERIOD
```
    See Also:
    
    Constant Field Values
  - 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
  - clone
```
protected Object clone()
                throws CloneNotSupportedException
```
    Overrides:
    
    clone in class Object
    
    Throws:
    
    CloneNotSupportedException
  - copy
```
public EntityReference copy()
```
    Returns:
    
    a copy of this reference
    
    See Also:
    
    copy(EntityReference)
  - 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
  - copy
```
public static EntityReference copy(EntityReference ref)
```
    Creates a copy of an entity reference
    
    Parameters:
    
    ref - an entity reference object
    
    Returns:
    
    the new copy of the ref
    
    Throws:
    
    IllegalArgumentException - if the ref is invalid OR null

Class EntityReference

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

serialVersionUID

SEPARATOR

PERIOD

originalReference

prefix

Constructor Detail

EntityReference

EntityReference

EntityReference

Method Detail

getOriginalReference

setOriginalReference

getPrefix

getId

isEmpty

makeEntityReference

makeEntityPrefix

makeEntityId

getReference

getSpaceReference

toString

clone

copy

getPrefix

getIdFromRef

getIdFromRefByKey

findPrefix

findId

getSeparatorPos

checkReference

checkPrefixId

copy