org.opencadc.vospace.server.AbstractView Maven / Gradle / Ivy
/*
************************************************************************
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*
* (c) 2023. (c) 2023.
* Government of Canada Gouvernement du Canada
* National Research Council Conseil national de recherches
* Ottawa, Canada, K1A 0R6 Ottawa, Canada, K1A 0R6
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*
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* expressed, implied, or énoncée, implicite ou légale,
* statutory, of any kind with de quelque nature que ce
* respect to the software, soit, concernant le logiciel,
* including without limitation y compris sans restriction
* any warranty of merchantability toute garantie de valeur
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* indirect, special or general, dommage, direct ou indirect,
* consequential or incidental, particulier ou général,
* arising from the use of the accessoire ou fortuit, résultant
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* of the National Research le nom du Conseil National de
* Council of Canada nor the Recherches du Canada ni les noms
* names of its contributors may de ses participants ne peuvent
* be used to endorse or promote être utilisés pour approuver ou
* products derived from this promouvoir les produits dérivés
* software without specific prior de ce logiciel sans autorisation
* written permission. préalable et particulière
* par écrit.
*
* This file is part of the Ce fichier fait partie du projet
* OpenCADC project. OpenCADC.
*
* OpenCADC is free software: OpenCADC est un logiciel libre ;
* you can redistribute it and/or vous pouvez le redistribuer ou le
* modify it under the terms of modifier suivant les termes de
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* License as published by the License” telle que publiée
* Free Software Foundation, par la Free Software Foundation
* either version 3 of the : soit la version 3 de cette
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* without even the implied GARANTIE : sans même la garantie
* warranty of MERCHANTABILITY implicite de COMMERCIALISABILITÉ
* or FITNESS FOR A PARTICULAR ni d’ADÉQUATION À UN OBJECTIF
* PURPOSE. See the GNU Affero PARTICULIER. Consultez la Licence
* General Public License for Générale Publique GNU Affero
* more details. pour plus de détails.
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* You should have received Vous devriez avoir reçu une
* a copy of the GNU Affero copie de la Licence Générale
* General Public License along Publique GNU Affero avec
* with OpenCADC. If not, see OpenCADC ; si ce n’est
* Generally, subclasses should implement setNode(Node, String) and either:
*
*
1) For views that result in a redirect:
* - getRedirectURL()
*
*
or, the set of:
*
*
2) For views that result in data returned:
* - write(OutputStream)
* - getContentLength()
* - getMediaType()
* - getEncodings()
* - getContentMD5()
*
*
The VOSpaceAuthorizer and NodePersistence objects are available to view implementations.
*
*
Please note: The node returned by getNode() has already gone through an authorization
* check using the VOSpaceAuthorizer.
*
* @author majorb
*/
public abstract class AbstractView extends View {
protected static Logger log = Logger.getLogger(AbstractView.class);
// The node for which to create the view
protected Node node;
protected URL requestURL;
// The node authorizer available for use
protected VOSpaceAuthorizer voSpaceAuthorizer;
// The node permisistence available for use
protected NodePersistence nodePersistence;
// The subject in which the view can choose to operate.
protected Subject subject;
/**
* AbstractView constructor.
*/
protected AbstractView() {
super();
loadSubject();
}
/**
* AbstractView constructor.
*
* @param uri The view identifier.
*/
public AbstractView(URI uri) {
super(uri);
loadSubject();
}
/**
* AbstractView constructor for service-side.
*
* @param uri The view identifier.
* @param original
*/
public AbstractView(URI uri, boolean original) {
super(uri, original);
loadSubject();
}
/**
* Get the node for this view.
*/
protected Node getNode() {
return node;
}
/**
* Get the VOSpaceAuthorizer
*
*
Note: The node available in getNode() has already gone
* through an authorization check with this authorizer.
*/
protected VOSpaceAuthorizer getVOSpaceAuthorizer() {
return voSpaceAuthorizer;
}
public void setVOSpaceAuthorizer(VOSpaceAuthorizer vospaceAuthorizer) {
this.voSpaceAuthorizer = vospaceAuthorizer;
}
/**
* Get the NodePersistence
*/
protected NodePersistence getNodePersistence() {
return nodePersistence;
}
public void setNodePersistence(NodePersistence nodePersistence) {
this.nodePersistence = nodePersistence;
}
/**
* Set the node to be used by the view.
*
* @param node The node to be used.
* @param viewReference The name used to reference this view.
* @param requestURL the original URL
* @throws UnsupportedOperationException If this view cannot be created for the given node.
*/
public void setNode(Node node, String viewReference, URL requestURL)
throws UnsupportedOperationException, TransientException {
if (node == null) {
throw new UnsupportedOperationException("BUG: node for view is null.");
}
if (requestURL == null) {
throw new UnsupportedOperationException("BUG: return requestURL for view is null.");
}
this.node = node;
this.requestURL = requestURL;
}
/**
* Return true if the supplied node accepts this view.
* The default implementation here always returns false.
*
* @param node node
*/
public boolean canAccept(Node node) {
return false;
}
/**
* Return true if the supplied node provides this view.
* The default implementation here always returns false.
*
* @param node node
*/
public boolean canProvide(Node node) {
return false;
}
/**
* Return the redirect URL for this view, or null if a redirect is not
* a result of the view.
*/
public URL getRedirectURL() {
return null;
}
/**
* Write the view data to the outputStream if that is the result of the view.
*
* @param outputStream The output stream on which to write.
* @throws IOException If an I/O problem occurs.
*/
public void write(OutputStream outputStream) throws IOException {
}
/**
* Return the content length of the data for the view.
*/
public long getContentLength() {
return 0;
}
/**
* Return the MD5 Checksum of the data for the view.
*/
public String getContentMD5() {
return null;
}
/**
* Return the last modification date of the Node.
*/
public Date getLastModified() {
NodeProperty modificationDate = node.getProperty(VOS.PROPERTY_URI_DATE);
if (modificationDate != null) {
try {
DateFormat df = DateUtil.getDateFormat(DateUtil.IVOA_DATE_FORMAT, DateUtil.UTC);
return df.parse(modificationDate.getValue());
} catch (ParseException e) {
log.warn("Date " + modificationDate.getValue()
+ " could not be parsed.");
}
}
return null;
}
private void loadSubject() {
AccessControlContext acContext = AccessController.getContext();
subject = Subject.getSubject(acContext);
}
}