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:

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

Methods

Modifier and Type	Method and Description
int	compareTo(MetadataKey<?> other) Compares first on ID, then on element type, then on datatype.
boolean	equals(Object obj)
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<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, Class<? extends T> datatype, Class<? extends V> elementType) Construct an element key with the given id, datatype, and element type.
static <V extends Element> ElementKey<Void,V>	of(QName id, Class<? extends V> elementType) Construct an element key with the given id and element type, but with a Void datatype.
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<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<Void,V> of(QName id,
                                        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,
                                       Class<? extends T> datatype,
                                       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 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 Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class MetadataKey<D>