/*
* Copyright 2002-2005 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sf.sojo.core.conversion;
import net.sf.sojo.core.SimpleConversion;
/**
* Handle <code>null</code> objects. <code>Null</code> - objects can replace with a placeholder.
*
* @author linke
*
*/
public class NullConversion extends SimpleConversion {
private Object nullReplaceObject = null;
private Class fromType = null;
public NullConversion(Object pvNullReplaceObject) {
super(String.class, String.class);
fromType = (pvNullReplaceObject == null ? String.class : pvNullReplaceObject.getClass());
toType = fromType;
setNullReplaceObject(pvNullReplaceObject);
}
public Object getNullReplaceObject() { return nullReplaceObject; }
public final void setNullReplaceObject(Object pvNullReplaceObject) { nullReplaceObject = pvNullReplaceObject; }
public boolean isAssignableFrom(Object pvObject) {
if (pvObject == null) {
return true;
} else if (pvObject.equals(getNullReplaceObject())) {
return true;
} else {
return false;
}
}
public boolean isAssignableTo(final Class pvToType) {
boolean b = fromType.isAssignableFrom(pvToType);
return b;
}
public Object convert(final Object pvObject, final Class pvToType) {
if (pvObject == null) {
return getNullReplaceObject();
} else {
// convert back to null-value
return null;
}
}
}
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