org.mycore.datamodel.common.MCRObjectMerger Maven / Gradle / Ivy
/*
* This file is part of *** M y C o R e ***
* See http://www.mycore.de/ for details.
*
* MyCoRe 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 3 of the License, or
* (at your option) any later version.
*
* MyCoRe 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 MyCoRe. If not, see .
*/
package org.mycore.datamodel.common;
import org.mycore.common.content.MCRJDOMContent;
import org.mycore.common.xml.MCRXMLParserFactory;
import org.mycore.datamodel.metadata.MCRMetaElement;
import org.mycore.datamodel.metadata.MCRMetaInterface;
import org.mycore.datamodel.metadata.MCRObject;
import org.mycore.datamodel.metadata.MCRObjectMetadata;
/**
* Helper class to merge mycore objects. Only metadata merging is
* currently supported.
*
* @author Matthias Eichner
*/
public class MCRObjectMerger {
protected MCRObject target;
/**
* Creates a new instance of the object merger. The target will be cloned for
* further processing. You will receive a copy when calling {@link #get()}.
*
* @param target the target mycore object
*/
public MCRObjectMerger(MCRObject target) {
this.target = new MCRObject(target.createXML());
}
/**
* Merges the metadata of the given source into the target object. Be aware that
* performance isn't that good when validation is activated, due checking against
* the schema each time a change is made.
*
* @param source the source which is merged into the target
* @param validate If true, every change is tracked and validated against the
* xml schema of the mycore object. When a change is invalid it will be
* canceled and the merging continues.
* When set to false the mycore object will be merged without validation.
* This can result in an invalid object.
*
* @return true if something was merged
*/
public boolean mergeMetadata(MCRObject source, boolean validate) {
MCRObjectMetadata targetMetadata = this.target.getMetadata();
boolean merged = false;
for (MCRMetaElement metaElementSource : source.getMetadata()) {
MCRMetaElement metaElementTarget = targetMetadata.getMetadataElement(metaElementSource.getTag());
if (metaElementTarget == null) {
targetMetadata.setMetadataElement(metaElementSource.clone());
if (validate && !validate(this.target)) {
targetMetadata.removeMetadataElement(metaElementSource.getTag());
} else {
merged = true;
}
} else {
for (MCRMetaInterface metaInterfaceSource : metaElementSource) {
boolean equal = false;
for (MCRMetaInterface metaInterfaceTarget : metaElementTarget) {
if (metaInterfaceSource.equals(metaInterfaceTarget)) {
equal = true;
break;
}
}
if (!equal) {
metaElementTarget.addMetaObject(metaInterfaceSource.clone());
if (validate && !validate(this.target)) {
metaElementTarget.removeMetaObject(metaInterfaceSource);
} else {
merged = true;
}
}
}
}
}
return merged;
}
/**
* Validates the given mcr object against its own schema.
*
* @param mcrobj the object to validate
* @return true if the object is valid, otherwise false
*/
protected boolean validate(MCRObject mcrobj) {
try {
MCRXMLParserFactory.getParser(true, true).parseXML(new MCRJDOMContent(mcrobj.createXML()));
return true;
} catch (Exception exc) {
return false;
}
}
/**
* Returns a copy of the merged target object.
*
*/
public MCRObject get() {
return this.target;
}
}