| 1 |
26600
|
sandro.lab
|
package eu.dnetlib.enabling.is.sn;
|
| 2 |
|
|
|
| 3 |
|
|
import java.io.StringWriter;
|
| 4 |
|
|
import java.util.Collection;
|
| 5 |
|
|
|
| 6 |
|
|
import javax.xml.transform.Transformer;
|
| 7 |
|
|
import javax.xml.transform.TransformerException;
|
| 8 |
|
|
import javax.xml.transform.TransformerFactory;
|
| 9 |
|
|
import javax.xml.transform.dom.DOMSource;
|
| 10 |
|
|
import javax.xml.transform.stream.StreamResult;
|
| 11 |
|
|
import javax.xml.xpath.XPath;
|
| 12 |
|
|
import javax.xml.xpath.XPathConstants;
|
| 13 |
|
|
import javax.xml.xpath.XPathExpressionException;
|
| 14 |
|
|
import javax.xml.xpath.XPathFactory;
|
| 15 |
|
|
|
| 16 |
|
|
import org.apache.commons.logging.Log;
|
| 17 |
|
|
import org.apache.commons.logging.LogFactory;
|
| 18 |
|
|
import org.w3c.dom.Node;
|
| 19 |
|
|
|
| 20 |
|
|
import eu.dnetlib.enabling.is.sn.resourcestate.ResourceStateNotificationDetector;
|
| 21 |
|
|
import eu.dnetlib.enabling.is.sn.resourcestate.ResourceStateSubscription;
|
| 22 |
|
|
import eu.dnetlib.enabling.is.sn.resourcestate.ResourceStateSubscriptionRegistry;
|
| 23 |
|
|
import eu.dnetlib.enabling.tools.OpaqueResource;
|
| 24 |
|
|
|
| 25 |
|
|
/**
|
| 26 |
|
|
* This notification detector uses a local xmldb trigger as a source of events.
|
| 27 |
|
|
*
|
| 28 |
|
|
* @author marko
|
| 29 |
|
|
*
|
| 30 |
|
|
*/
|
| 31 |
|
|
public class NotificationDetectorImpl extends AbstractNotificationDetector implements ResourceStateNotificationDetector<OpaqueResource> {
|
| 32 |
|
|
|
| 33 |
|
|
/**
|
| 34 |
|
|
* logger.
|
| 35 |
|
|
*/
|
| 36 |
|
|
private static final Log log = LogFactory.getLog(NotificationDetectorImpl.class); // NOPMD by marko on 11/24/08 5:02 PM
|
| 37 |
|
|
|
| 38 |
|
|
/**
|
| 39 |
|
|
* subscription registries to lookup.
|
| 40 |
|
|
*/
|
| 41 |
43289
|
claudio.at
|
private SubscriptionRegistry registry;
|
| 42 |
26600
|
sandro.lab
|
|
| 43 |
|
|
/**
|
| 44 |
|
|
* {@inheritDoc}
|
| 45 |
|
|
*
|
| 46 |
|
|
* @see eu.dnetlib.enabling.is.sn.resourcestate.ResourceStateNotificationDetector#resourceCreated(java.lang.Object)
|
| 47 |
|
|
*/
|
| 48 |
|
|
@Override
|
| 49 |
|
|
public void resourceCreated(final OpaqueResource newResource) {
|
| 50 |
43289
|
claudio.at
|
log.debug("resource created: " + getRegistry());
|
| 51 |
|
|
|
| 52 |
|
|
final Collection<ResourceStateSubscription> subs =
|
| 53 |
|
|
getRegistry().listMatchingSubscriptions(ResourceStateSubscription.PREFIX_CREATE, newResource.getResourceType(), newResource.getResourceId());
|
| 54 |
|
|
for (ResourceStateSubscription sub : subs) {
|
| 55 |
|
|
if (matchPath(newResource, sub.getXpath())) {
|
| 56 |
|
|
send(sub, newResource, ResourceStateSubscription.PREFIX_CREATE);
|
| 57 |
|
|
}
|
| 58 |
26600
|
sandro.lab
|
}
|
| 59 |
|
|
}
|
| 60 |
|
|
|
| 61 |
|
|
/**
|
| 62 |
|
|
* helper method. sends a notification for a given prefix.
|
| 63 |
|
|
*
|
| 64 |
|
|
* @param sub
|
| 65 |
|
|
* subscription
|
| 66 |
|
|
* @param resource
|
| 67 |
|
|
* resource
|
| 68 |
|
|
* @param prefix
|
| 69 |
|
|
* prefix
|
| 70 |
|
|
*/
|
| 71 |
|
|
private void send(final ResourceStateSubscription sub, final OpaqueResource resource, final String prefix) {
|
| 72 |
|
|
log.debug("RESOURCE " + resource);
|
| 73 |
|
|
log.debug("id: " + resource.getResourceId());
|
| 74 |
|
|
log.debug("dom: " + resource.asDom());
|
| 75 |
|
|
|
| 76 |
|
|
final StringBuffer topicBuffer = new StringBuffer();
|
| 77 |
|
|
|
| 78 |
|
|
if (sub.getPrefix() == null && "*".equals(sub.getPrefix()))
|
| 79 |
|
|
topicBuffer.append(prefix);
|
| 80 |
|
|
else
|
| 81 |
|
|
topicBuffer.append(sub.getPrefix());
|
| 82 |
|
|
|
| 83 |
|
|
topicBuffer.append('.');
|
| 84 |
|
|
topicBuffer.append(sub.getType());
|
| 85 |
|
|
topicBuffer.append('.');
|
| 86 |
|
|
topicBuffer.append(sub.getResourceId());
|
| 87 |
|
|
if (sub.getXpath() != null && !sub.getXpath().isEmpty()) {
|
| 88 |
|
|
topicBuffer.append(sub.getXpath().replace('/', '.'));
|
| 89 |
|
|
}
|
| 90 |
|
|
|
| 91 |
|
|
getSender().send(sub.getSubscriberAsEpr(), new NotificationMessage(sub.getSubscriptionId(), topicBuffer.toString(), resource.getResourceId(), // NOPMD
|
| 92 |
|
|
resource.asString()));
|
| 93 |
|
|
}
|
| 94 |
|
|
|
| 95 |
|
|
/**
|
| 96 |
|
|
* {@inheritDoc}
|
| 97 |
|
|
*
|
| 98 |
|
|
* @see eu.dnetlib.enabling.is.sn.resourcestate.ResourceStateNotificationDetector#resourceDeleted(java.lang.Object)
|
| 99 |
|
|
*/
|
| 100 |
|
|
@Override
|
| 101 |
|
|
public void resourceDeleted(final OpaqueResource oldResource) {
|
| 102 |
43289
|
claudio.at
|
log.debug("resource deleted: " + getRegistry());
|
| 103 |
|
|
|
| 104 |
|
|
final Collection<ResourceStateSubscription> subs =
|
| 105 |
|
|
registry.listMatchingSubscriptions(ResourceStateSubscription.PREFIX_DELETE, oldResource.getResourceType(), oldResource.getResourceId());
|
| 106 |
|
|
for (ResourceStateSubscription sub : subs) {
|
| 107 |
|
|
if (matchPath(oldResource, sub.getXpath())) {
|
| 108 |
|
|
send(sub, oldResource, ResourceStateSubscription.PREFIX_DELETE);
|
| 109 |
|
|
}
|
| 110 |
26600
|
sandro.lab
|
}
|
| 111 |
|
|
}
|
| 112 |
|
|
|
| 113 |
|
|
/**
|
| 114 |
|
|
* {@inheritDoc}
|
| 115 |
|
|
*
|
| 116 |
|
|
* @see eu.dnetlib.enabling.is.sn.resourcestate.ResourceStateNotificationDetector#resourceUpdated(java.lang.Object,
|
| 117 |
|
|
* java.lang.Object)
|
| 118 |
|
|
*/
|
| 119 |
|
|
@Override
|
| 120 |
|
|
public void resourceUpdated(final OpaqueResource oldResource, final OpaqueResource newResource) {
|
| 121 |
43289
|
claudio.at
|
log.debug("resource updated: " + getRegistry());
|
| 122 |
|
|
|
| 123 |
|
|
final Collection<ResourceStateSubscription> subs =
|
| 124 |
|
|
registry.listMatchingSubscriptions(ResourceStateSubscription.PREFIX_UPDATE, oldResource.getResourceType(), oldResource.getResourceId());
|
| 125 |
|
|
for (ResourceStateSubscription sub : subs) {
|
| 126 |
|
|
if (comparePath(oldResource, newResource, sub.getXpath())) {
|
| 127 |
|
|
log.debug("updated, sending: " + newResource.asString());
|
| 128 |
|
|
send(sub, newResource, ResourceStateSubscription.PREFIX_UPDATE);
|
| 129 |
|
|
}
|
| 130 |
26600
|
sandro.lab
|
}
|
| 131 |
|
|
}
|
| 132 |
|
|
|
| 133 |
|
|
/**
|
| 134 |
|
|
* check if an xpath matches a given resource.
|
| 135 |
|
|
*
|
| 136 |
|
|
* @param resource
|
| 137 |
|
|
* resource
|
| 138 |
|
|
* @param xpath
|
| 139 |
|
|
* xpath
|
| 140 |
|
|
* @return true if the resource has some value for the given path
|
| 141 |
|
|
*/
|
| 142 |
|
|
private boolean matchPath(final OpaqueResource resource, final String xpath) {
|
| 143 |
|
|
// by convention empty xpath matches any document
|
| 144 |
|
|
if (xpath == null || xpath.isEmpty())
|
| 145 |
|
|
return true;
|
| 146 |
|
|
|
| 147 |
|
|
final XPath xpa = XPathFactory.newInstance().newXPath();
|
| 148 |
|
|
try {
|
| 149 |
|
|
return !xpa.evaluate(xpath, resource.asDom()).isEmpty();
|
| 150 |
|
|
} catch (XPathExpressionException e) {
|
| 151 |
|
|
log.warn("wrong xpath expression, notification possibly missed", e);
|
| 152 |
|
|
}
|
| 153 |
|
|
return false;
|
| 154 |
|
|
}
|
| 155 |
|
|
|
| 156 |
|
|
/**
|
| 157 |
|
|
* compare the content of two profiles for the same xpath. Return true if some change has been made so that the
|
| 158 |
|
|
* notification can be delivered.
|
| 159 |
|
|
*
|
| 160 |
|
|
* @param oldResource
|
| 161 |
|
|
* old version
|
| 162 |
|
|
* @param newResource
|
| 163 |
|
|
* new version
|
| 164 |
|
|
* @param xpath
|
| 165 |
|
|
* XPath
|
| 166 |
|
|
* @return true if the two documents differ under a given path
|
| 167 |
|
|
*/
|
| 168 |
|
|
private boolean comparePath(final OpaqueResource oldResource, final OpaqueResource newResource, final String xpath) {
|
| 169 |
|
|
// by convention empty xpath matches any document
|
| 170 |
|
|
if (oldResource == null || newResource == null || xpath == null || xpath.isEmpty())
|
| 171 |
|
|
return true;
|
| 172 |
|
|
|
| 173 |
|
|
final XPath xpa = XPathFactory.newInstance().newXPath();
|
| 174 |
|
|
try {
|
| 175 |
|
|
final Transformer transformer = TransformerFactory.newInstance().newTransformer();
|
| 176 |
|
|
|
| 177 |
|
|
final Node left = (Node) xpa.evaluate(xpath, oldResource.asDom(), XPathConstants.NODE);
|
| 178 |
|
|
final Node right = (Node) xpa.evaluate(xpath, newResource.asDom(), XPathConstants.NODE);
|
| 179 |
|
|
|
| 180 |
|
|
if (left==null || right==null) {
|
| 181 |
|
|
if (left != null) {
|
| 182 |
|
|
return true;
|
| 183 |
|
|
}
|
| 184 |
|
|
else {
|
| 185 |
|
|
if (right != null) {
|
| 186 |
|
|
return true;
|
| 187 |
|
|
}
|
| 188 |
|
|
else {
|
| 189 |
|
|
return false;
|
| 190 |
|
|
}
|
| 191 |
|
|
}
|
| 192 |
|
|
}
|
| 193 |
|
|
|
| 194 |
|
|
final StringWriter leftWriter = new StringWriter();
|
| 195 |
|
|
final StringWriter rightWriter = new StringWriter();
|
| 196 |
|
|
|
| 197 |
|
|
transformer.transform(new DOMSource(left), new StreamResult(leftWriter));
|
| 198 |
|
|
transformer.transform(new DOMSource(right), new StreamResult(rightWriter));
|
| 199 |
|
|
|
| 200 |
|
|
return !leftWriter.toString().equals(rightWriter.toString());
|
| 201 |
|
|
} catch (XPathExpressionException e) {
|
| 202 |
|
|
log.warn("wrong xpath expression, notification possibly missed", e);
|
| 203 |
|
|
} catch (TransformerException e) {
|
| 204 |
|
|
log.warn("serialization problem", e);
|
| 205 |
|
|
}
|
| 206 |
|
|
|
| 207 |
|
|
return false;
|
| 208 |
|
|
}
|
| 209 |
|
|
|
| 210 |
43289
|
claudio.at
|
public SubscriptionRegistry getRegistry() {
|
| 211 |
|
|
return registry;
|
| 212 |
26600
|
sandro.lab
|
}
|
| 213 |
|
|
|
| 214 |
43289
|
claudio.at
|
public void setRegistry(final SubscriptionRegistry registry) {
|
| 215 |
|
|
this.registry = registry;
|
| 216 |
26600
|
sandro.lab
|
}
|
| 217 |
|
|
}
|