org.simpleframework.xml.strategy.Value Maven / Gradle / Ivy
/*
* Value.java January 2007
*
* Copyright (C) 2007, Niall Gallagher
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.strategy;
/**
* The Value object describes a type that is represented
* by an XML element. This enables a Strategy to define
* not only the type an element represents, but also defines if that
* type needs to be created. This allows arrays as well as standard
* object types to be described. When instantiated the instance should
* be set on the value object for use by the strategy to detect cycles.
*
* @author Niall Gallagher
*
* @see org.simpleframework.xml.strategy.Strategy
*/
public interface Value {
/**
* This method is used to acquire an instance of the type that
* is defined by this object. If the value has not been set
* then this method will return null if this is not a reference.
*
* @return an instance of the type this object represents
*/
public Object getValue();
/**
* This method is used set the value within this object. Once
* this is set then the getValue method will return
* the object that has been provided for consistency.
*
* @param value this is the value to insert as the type
*/
public void setValue(Object value);
/**
* This is the type of the object instance this represents. The
* type returned by this is used to instantiate an object which
* will be set on this value and the internal graph maintained.
*
* @return the type of the object that must be instantiated
*/
public Class getType();
/**
* This returns the length of the array that is to be allocated.
* If this value does not represent an array then this should
* return zero to indicate that it is not an array object.
*
* @return this returns the number of elements for the array
*/
public int getLength();
/**
* This will return true if the object represents a reference.
* A reference will provide a valid instance when this objects
* getter is invoked. A valid instance can be a null.
*
* @return this returns true if this represents a reference
*/
public boolean isReference();
}