[
https://issues.apache.org/jira/browse/SIS-113?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13931631#comment-13931631
]
Martin Desruisseaux commented on SIS-113:
-----------------------------------------
Example of a possible implementation:
{code:java}
import java.util.Map;
import java.util.List;
import java.util.ArrayList;
import java.util.Collection;
import java.util.IdentityHashMap;
import org.apache.sis.metadata.AbstractMetadata;
import org.apache.sis.metadata.KeyNamePolicy;
import org.apache.sis.metadata.ValueExistencePolicy;
public class DeepCopy {
public static AbstractMetadata clone(final AbstractMetadata metadata) {
return clone(metadata, new
IdentityHashMap<AbstractMetadata,AbstractMetadata>());
}
private static AbstractMetadata clone(final AbstractMetadata metadata,
final Map<AbstractMetadata,AbstractMetadata> done) {
AbstractMetadata clone = done.get(metadata);
if (clone == null) {
clone = shallowCopy(metadata);
done.put(metadata, clone);
for (Map.Entry<String,Object> entry :
clone.getStandard().asValueMap(metadata,
KeyNamePolicy.JAVABEANS_PROPERTY,
ValueExistencePolicy.NON_NULL).entrySet())
{
final Object value = entry.getValue();
if (value instanceof AbstractMetadata) {
entry.setValue(clone((AbstractMetadata) value, done));
} else if (value instanceof Collection<?>) {
final List<Object> list = new ArrayList<>((Collection<?>)
value);
boolean modified = false;
for (int i=list.size(); --i>=0;) {
final Object element = list.get(i);
if (element instanceof AbstractMetadata) {
list.set(i, clone((AbstractMetadata) element,
done));
modified = true;
}
}
if (modified) {
entry.setValue(list);
}
}
}
}
return clone;
}
private static AbstractMetadata shallowCopy(final AbstractMetadata
metadata) {
final Class<?> c = metadata.getClass();
try {
return (AbstractMetadata)
c.getConstructor(metadata.getStandard().getInterface(c)).newInstance(metadata);
} catch (ReflectiveOperationException e) {
throw new IllegalArgumentException("Malformed metadata class.", e);
// TODO: define a better exception.
}
}
}
{code}
> Support deep copy of metadata objects
> -------------------------------------
>
> Key: SIS-113
> URL: https://issues.apache.org/jira/browse/SIS-113
> Project: Spatial Information Systems
> Issue Type: New Feature
> Components: Metadata
> Affects Versions: 0.3
> Reporter: Martin Desruisseaux
> Assignee: Martin Desruisseaux
>
> Current metadata implementations provide constructors performing shallow copy
> of metadata objects. We also need a method providing a deep copy. It shall
> not be a constructor (using reflection in constructors is unsafe).
--
This message was sent by Atlassian JIRA
(v6.2#6252)
