com.google.gdata.model
Class ElementKey<D,E extends Element>

java.lang.Object
  com.google.gdata.model.MetadataKey<D>
      com.google.gdata.model.ElementKey<D,E>

Type Parameters:

D - the datatype of the element

E - the element type of the element

All Implemented Interfaces:

java.lang.Comparable<MetadataKey<?>>

public final class ElementKey<D,E extends Element>
extends MetadataKey<D>

A key referring to a particular element. Holds the ID of the element and the expected datatype and element type. Element keys support value-based equality, natural ordering, and matching.

• An element key is equals(Object) to another element key if their IDs are equivalent or both null, and their datatypes, and element types are the same.
• An element key's natural ordering is based first on the name, then on the element type, and finally on the data type.
• An element key matches(MetadataKey) another element key if the ID is a match for the ID of the other key, and the datatype and element type are both assignable from the other key's datatype and element type.

Method Summary

int	compareTo(MetadataKey<?> other) Compares first on ID, then on element type, then on datatype.
boolean	equals(java.lang.Object obj)
java.lang.Class<? extends E>	getElementType() Returns the element type of the element.
int	hashCode()
boolean	matches(MetadataKey<?> other) Returns true if this key is a match for the given key.
static ElementKey<java.lang.String,Element>	of(QName id) Return a default element key using a string datatype and Element as the element type.
static <T,V extends Element> ElementKey<T,V>	of(QName id, java.lang.Class<? extends T> datatype, java.lang.Class<? extends V> elementType) Construct an element key with the given id, datatype, and element type.
static <V extends Element> ElementKey<java.lang.Void,V>	of(QName id, java.lang.Class<? extends V> elementType) Construct an element key with the given id and element type, but with a Void datatype.
java.lang.String	toString()

Methods inherited from class com.google.gdata.model.MetadataKey

getDatatype, getId

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

of

public static ElementKey<java.lang.String,Element> of(QName id)

Return a default element key using a string datatype and Element as the element type. The id must not be null.

of

public static <V extends Element> ElementKey<java.lang.Void,V> of(QName id,
                                                                  java.lang.Class<? extends V> elementType)

Construct an element key with the given id and element type, but with a Void datatype. This is used for elements without text content.

The elementType must not be null. A null id is only valid for element types that are a subclass of Element, and are used as a key referring to all instances of that element type.

of

public static <T,V extends Element> ElementKey<T,V> of(QName id,
                                                       java.lang.Class<? extends T> datatype,
                                                       java.lang.Class<? extends V> elementType)

Construct an element key with the given id, datatype, and element type. This is used for elements that contain text content.

The elementType must not be null. A null id is only valid for element types that are a subclass of Element, and are used as a key referring to all instances of that element type.

getElementType

public java.lang.Class<? extends E> getElementType()

Returns the element type of the element.

matches

public boolean matches(MetadataKey<?> other)

Returns true if this key is a match for the given key. This key is a match for the other key if the other key is also an element key and if the ID, datatype, and element types all match.

Specified by:

matches in class MetadataKey<D>

compareTo

public int compareTo(MetadataKey<?> other)

Compares first on ID, then on element type, then on datatype.

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class MetadataKey<D>