org.geotools.util.decorate

Class AbstractDecorator<D>

Object

AbstractDecorator<D>

All Implemented Interfaces:

Serializable, Wrapper

Direct Known Subclasses:

DecoratingDataStore

public class AbstractDecorator<D>
extends Object
implements Wrapper, Serializable

Generic delegating base class. Provides the following features:

• null check for the delegate object
• direct forwarding of equals(Object), hashCode() and toString() to the delegate
• implements the Wrapper interface for programmatic extraction

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected D	delegate

Constructor Summary

Constructors

Constructor and Description
AbstractDecorator(D delegate)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
int	hashCode()
boolean	isWrapperFor(Class<?> iface) Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does.
String	toString()
<T> T	unwrap(Class<T> iface) Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.

Methods inherited from class Object

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

Field Detail

delegate

protected D delegate

Constructor Detail

AbstractDecorator

public AbstractDecorator(D delegate)

Method Detail

isWrapperFor

public boolean isWrapperFor(Class<?> iface)

Description copied from interface: Wrapper

Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does. Returns false otherwise. If this implements the interface then return true, else if this is a wrapper then return the result of recursively calling isWrapperFor on the wrapped object. If this does not implement the interface and is not a wrapper, return false. This method should be implemented as a low-cost operation compared to unwrap so that callers can use this method to avoid expensive unwrap calls that may fail. If this method returns true then calling unwrap with the same argument should succeed.

Specified by:

isWrapperFor in interface Wrapper

Parameters:

iface - a Class defining an interface.

Returns:

true if this implements the interface or directly or indirectly wraps an object that does.

unwrap

public <T> T unwrap(Class<T> iface)
             throws IllegalArgumentException

Description copied from interface: Wrapper

Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.

If the receiver implements the interface then the result is the receiver or a proxy for the receiver. If the receiver is a wrapper and the wrapped object implements the interface then the result is the wrapped object or a proxy for the wrapped object. Otherwise return the the result of calling unwrap recursively on the wrapped object or a proxy for that result. If the receiver is not a wrapper and does not implement the interface, then an IllegalArgumentException is thrown.

Specified by:

unwrap in interface Wrapper

Parameters:

iface - A Class defining an interface that the result must implement.

Returns:

an object that implements the interface. May be a proxy for the actual implementing object.

Throws:

IllegalArgumentException - If no object found that implements the interface

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object