Module org.apache.wicket.core

Package org.apache.wicket

Class MetaDataKey<T>

java.lang.Object

org.apache.wicket.MetaDataKey<T>

Type Parameters:

T - The type of the object which is stored

All Implemented Interfaces:

Serializable, IClusterable

public abstract class MetaDataKey<T>
extends Object
implements IClusterable

A key to a piece of metadata associated with a Component, Session or Application at runtime. The key contains type information that can be used to check the type of any metadata value for the key when the value is set. MetaDataKey is abstract in order to force the creation of a subtype. That subtype is used to test for identity when looking for the metadata because actual object identity would suffer from problems under serialization. So, the correct way to declare a MetaDataKey is like this:

 
 public static final MetaDataKey<Role> ROLE = new MetaDataKey<Role>() { };
 
 

Author:

Jonathan Locke

See Also:

• Session.getMetaData(MetaDataKey)
• Component.getMetaData(MetaDataKey)
• Application.getMetaData(MetaDataKey)
• Serialized Form

Constructor Summary

Constructors

Constructor	Description
MetaDataKey()	Constructor.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)
T	get(MetaDataEntry<?>[] metaData)
int	hashCode()
MetaDataEntry<?>[]	set(MetaDataEntry<?>[] metaData, Object object)
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

MetaDataKey

public MetaDataKey()

Constructor.

Method Details

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

See Also:

• Object.equals(java.lang.Object)

get

public T get(MetaDataEntry<?>[] metaData)

Parameters:

metaData - Array of metadata to search

Returns:

The entry value

set

public MetaDataEntry<?>[] set(MetaDataEntry<?>[] metaData,
 Object object)

Parameters:

metaData - The array of metadata

object - The object to set, null to remove

Returns:

Any new metadata array (if it was reallocated)

toString

public String toString()

Overrides:

toString in class Object

See Also:

• Object.toString()