Package org.geotools.util.decorate
Interface Wrapper
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- All Superinterfaces:
Wrapper
- All Known Implementing Classes:
AbstractDecorator
,DecoratingDataStore
public interface Wrapper extends Wrapper
Interface for classes which provide the ability to retrieve the delegate instance when the instance in question is in fact a proxy/decorator class.Developers may wish to gain access to the resources that are wrapped (the delegates) as proxy class instances representing the the actual resources.
This interface extends JDK Wrapper class, overriding the thrown exception with a more meaningful named one.
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description 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.<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.
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Method Detail
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isWrapperFor
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. Returns false otherwise. If this implements the interface then return true, else if this is a wrapper then return the result of recursively callingisWrapperFor
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 tounwrap
so that callers can use this method to avoid expensiveunwrap
calls that may fail. If this method returns true then callingunwrap
with the same argument should succeed.- Specified by:
isWrapperFor
in interfaceWrapper
- Parameters:
iface
- a Class defining an interface.- Returns:
- true if this implements the interface or directly or indirectly wraps an object that does.
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unwrap
<T> T unwrap(Class<T> iface) throws IllegalArgumentException
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 anIllegalArgumentException
is thrown.- Specified by:
unwrap
in interfaceWrapper
- 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
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