Package org.apache.commons.configuration2

Class ImmutableConfigurationInvocationHandler

java.lang.Object

org.apache.commons.configuration2.ImmutableConfigurationInvocationHandler

All Implemented Interfaces:

InvocationHandler

final class ImmutableConfigurationInvocationHandler
extends Object
implements InvocationHandler

A specialized InvocationHandler implementation for supporting immutable configurations.

An instance of this class is constructed with a reference to a Configuration object. All method invocations (which stem from the ImmutableConfiguration interface) are delegated to this object. That way all functionality is actually backed by the underlying Configuration implementation, but because the associated proxy only implements the ImmutableConfiguration interface manipulations are not possible.

There is one caveat however: Some methods of the ImmutableConfiguration interface return an Iterator object. Using the iterator's remove() method it may be possible to remove keys from the underlying Configuration object. Therefore, in these cases a specialized Iterator is returned which does not support the remove operation.

Since:

2.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	ImmutableConfigurationInvocationHandler.ImmutableIterator	A specialized Iterator implementation which delegates to an underlying iterator, but does not support the remove() method.

Field Summary

Fields

Modifier and Type	Field	Description
private final Configuration	wrappedConfiguration	The underlying configuration object.

Constructor Summary

Constructors

Constructor	Description
ImmutableConfigurationInvocationHandler(Configuration configuration)	Creates a new instance of ImmutableConfigurationInvocationHandler and initializes it with the wrapped configuration object.

Method Summary

Modifier and Type	Method	Description
private static Object	handleResult(Object result)	Handles the result from the method invocation on the wrapped configuration.
Object	invoke(Object proxy, Method method, Object[] args)	This implementation delegates to the wrapped configuration object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

wrappedConfiguration

private final Configuration wrappedConfiguration

The underlying configuration object.

Constructor Details

ImmutableConfigurationInvocationHandler

public ImmutableConfigurationInvocationHandler(Configuration configuration)

Creates a new instance of ImmutableConfigurationInvocationHandler and initializes it with the wrapped configuration object.

Parameters:

configuration - the wrapped Configuration (must not be null)

Throws:

NullPointerException - if the Configuration is null

Method Details

handleResult

private static Object handleResult(Object result)

Handles the result from the method invocation on the wrapped configuration. This implementation wraps result objects if necessary so that the underlying configuration cannot be manipulated.

Parameters:

result - the result object

Returns:

the processed result object

invoke

public Object invoke(Object proxy,
 Method method,
 Object[] args)
              throws Throwable

This implementation delegates to the wrapped configuration object. Result objects are wrapped if necessary.

Specified by:

invoke in interface InvocationHandler

Throws:

Throwable