mirror of git://gcc.gnu.org/git/gcc.git
114 lines
4.1 KiB
Java
114 lines
4.1 KiB
Java
/* gnu.java.beans.decoder.AbstractCreatableContext
|
|
Copyright (C) 2004 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath 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
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
02110-1301 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
package gnu.java.beans.decoder;
|
|
|
|
|
|
/** AbstractCreatableObjectContext is the base class for all Context implementations
|
|
* which create a result object in their lifetime. It provides means for preventing
|
|
* to create the object twice.
|
|
*
|
|
* @author Robert Schuster
|
|
*
|
|
*/
|
|
abstract class AbstractCreatableObjectContext extends AbstractObjectContext
|
|
{
|
|
AbstractCreatableObjectContext()
|
|
{
|
|
}
|
|
|
|
/** Adds a parameter object to this Context if the result object has not been
|
|
* created yet. Otherwise an AssemblyException is thrown that indicates a wrong
|
|
* behavior of the decoder.
|
|
*/
|
|
public final void addParameterObject(Object o) throws AssemblyException
|
|
{
|
|
if (object == null)
|
|
addParameterObjectImpl(o);
|
|
else
|
|
throw new AssemblyException(new IllegalStateException("No more parameter objects are allowed when the object as already been created."));
|
|
}
|
|
|
|
/** Adds a parameter object to this Context. Implement this without caring
|
|
* for illegal states because this has been done already.
|
|
*
|
|
* @param obj The parameter object to be added.
|
|
*/
|
|
protected abstract void addParameterObjectImpl(Object obj);
|
|
|
|
/** Creates the result object if it does not exist already.
|
|
*/
|
|
public final void notifyStatement(Context outerContext)
|
|
throws AssemblyException
|
|
{
|
|
if (object != null)
|
|
return;
|
|
|
|
object = createObject(outerContext);
|
|
}
|
|
|
|
/** Creates the result object. This method is called only once. Implement this
|
|
* without checking for double invocations as this is already being prevented.
|
|
*
|
|
* @param outerContext The Context that exists around this one.
|
|
* @return The result object.
|
|
* @throws AssemblerException if the object creation fails somehow.
|
|
*/
|
|
protected abstract Object createObject(Context outerContext)
|
|
throws AssemblyException;
|
|
|
|
/* (non-Javadoc)
|
|
* @see gnu.java.beans.decoder.Context#endContext(gnu.java.beans.decoder.Context)
|
|
*/
|
|
public final Object endContext(Context outerContext)
|
|
throws AssemblyException
|
|
{
|
|
notifyStatement(outerContext);
|
|
return object;
|
|
}
|
|
|
|
/* (non-Javadoc)
|
|
* @see gnu.java.beans.decoder.Context#subContextFailed()
|
|
*/
|
|
public boolean subContextFailed()
|
|
{
|
|
/* Returns true when the AbstractCreatableObjectContext has not created the result object yet
|
|
* (A failed subcontext automatically lets this context fail too.)
|
|
*/
|
|
return object == null;
|
|
}
|
|
}
|