org.jfree.xml.factory.objects.CollectionObjectDescription Maven / Gradle / Ivy
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/* ========================================================================
* JCommon : a free general purpose class library for the Java(tm) platform
* ========================================================================
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jcommon/index.html
*
* 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; either version 2.1 of the License, or
* (at your option) any later version.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ----------------------
* ObjectDescription.java
* ----------------------
* (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
*
* Original Author: Thomas Morgner;
* Contributor(s): David Gilbert (for Object Refinery Limited);
*
* $Id: CollectionObjectDescription.java,v 1.2 2005/10/18 13:31:58 mungady Exp $
*
* Changes
* -------------------------
* 06-May-2003 : Initial version
*/
package org.jfree.xml.factory.objects;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import org.jfree.util.Log;
/**
* An object description for simple collection objects, like java.util.List
* or java.util.Set.
*
* @author Thomas Morgner
*/
public class CollectionObjectDescription extends AbstractObjectDescription {
/**
* Creates a list object description for the given collection class.
*
* Throws ClassCastException if the given class is no collection instance.
*
* @param c the class of the collection implementation.
*/
public CollectionObjectDescription(final Class c) {
super(c);
if (!Collection.class.isAssignableFrom(c)) {
throw new ClassCastException("The given class is no Collection instance");
}
}
/**
* Tries to parse the given parameter string into a positive integer.
* Returns -1 if the parsing failed for some reason.
*
* @param name the name of the parameter.
* @return the parsed int value or -1 on errors.
*/
private int parseParameterName(final String name) {
try {
return Integer.parseInt(name);
}
catch (Exception e) {
return -1;
}
}
/**
* Returns a parameter definition. If the parameter is invalid, this
* function returns null.
*
* @param name the definition name.
*
* @return The parameter class or null, if the parameter is not defined.
*/
public Class getParameterDefinition(final String name) {
if (name.equals("size")) {
return Integer.TYPE;
}
final int par = parseParameterName(name);
if (par < 0) {
return null;
}
return Object.class;
}
/**
* Returns an iterator for the parameter names.
*
* @return The iterator.
*/
public Iterator getParameterNames() {
final Integer size = (Integer) getParameter("size");
if (size == null) {
return getDefinedParameterNames();
}
else {
final ArrayList l = new ArrayList();
l.add("size");
for (int i = 0; i < size.intValue(); i++) {
l.add(String.valueOf(i));
}
return l.iterator();
}
}
/**
* Creates an object based on the description.
*
* @return The object.
*/
public Object createObject() {
try {
final Collection l = (Collection) getObjectClass().newInstance();
int counter = 0;
while (getParameterDefinition(String.valueOf(counter)) != null) {
final Object value = getParameter(String.valueOf(counter));
if (value == null) {
break;
}
l.add(value);
counter += 1;
}
return l;
}
catch (Exception ie) {
Log.warn("Unable to instantiate Object", ie);
return null;
}
}
/**
* Sets the parameters of this description object to match the supplied object.
*
* @param o the object.
*
* @throws ObjectFactoryException if there is a problem while reading the
* properties of the given object.
*/
public void setParameterFromObject(final Object o) throws ObjectFactoryException {
if (o == null) {
throw new NullPointerException("Given object is null");
}
final Class c = getObjectClass();
if (!c.isInstance(o)) {
throw new ObjectFactoryException("Object is no instance of " + c + "(is "
+ o.getClass() + ")");
}
final Collection l = (Collection) o;
final Iterator it = l.iterator();
int counter = 0;
while (it.hasNext()) {
final Object ob = it.next();
setParameter(String.valueOf(counter), ob);
counter++;
}
}
}