org.argeo.core/src/org/argeo/jcr/proxy/AbstractUrlProxy.java

   1 package org.argeo.jcr.proxy;
   2
   3 import java.io.IOException;
   4 import java.io.InputStream;
   5 import java.net.URL;
   6
   7 import javax.jcr.Binary;
   8 import javax.jcr.Node;
   9 import javax.jcr.Property;
  10 import javax.jcr.Repository;
  11 import javax.jcr.RepositoryException;
  12 import javax.jcr.Session;
  13 import javax.jcr.nodetype.NodeType;
  14
  15 import org.apache.commons.logging.Log;
  16 import org.apache.commons.logging.LogFactory;
  17 import org.argeo.jcr.JcrException;
  18 import org.argeo.jcr.JcrUtils;
  19
  20 /** Base class for URL based proxys. */
  21 public abstract class AbstractUrlProxy implements ResourceProxy {
  22         private final static Log log = LogFactory.getLog(AbstractUrlProxy.class);
  23
  24         private Repository jcrRepository;
  25         private Session jcrAdminSession;
  26         private String proxyWorkspace = "proxy";
  27
  28         protected abstract Node retrieve(Session session, String path);
  29
  30         void init() {
  31                 try {
  32                         jcrAdminSession = JcrUtils.loginOrCreateWorkspace(jcrRepository, proxyWorkspace);
  33                         beforeInitSessionSave(jcrAdminSession);
  34                         if (jcrAdminSession.hasPendingChanges())
  35                                 jcrAdminSession.save();
  36                 } catch (RepositoryException e) {
  37                         JcrUtils.discardQuietly(jcrAdminSession);
  38                         throw new JcrException("Cannot initialize URL proxy", e);
  39                 }
  40         }
  41
  42         /**
  43          * Called before the (admin) session is saved at the end of the initialization.
  44          * Does nothing by default, to be overridden.
  45          */
  46         protected void beforeInitSessionSave(Session session) throws RepositoryException {
  47         }
  48
  49         void destroy() {
  50                 JcrUtils.logoutQuietly(jcrAdminSession);
  51         }
  52
  53         /**
  54          * Called before the (admin) session is logged out when resources are released.
  55          * Does nothing by default, to be overridden.
  56          */
  57         protected void beforeDestroySessionLogout() throws RepositoryException {
  58         }
  59
  60         public Node proxy(String path) {
  61                 // we open a JCR session with client credentials in order not to use the
  62                 // admin session in multiple thread or make it a bottleneck.
  63                 Node nodeAdmin = null;
  64                 Node nodeClient = null;
  65                 Session clientSession = null;
  66                 try {
  67                         clientSession = jcrRepository.login(proxyWorkspace);
  68                         if (!clientSession.itemExists(path) || shouldUpdate(clientSession, path)) {
  69                                 nodeAdmin = retrieveAndSave(path);
  70                                 if (nodeAdmin != null)
  71                                         nodeClient = clientSession.getNode(path);
  72                         } else
  73                                 nodeClient = clientSession.getNode(path);
  74                         return nodeClient;
  75                 } catch (RepositoryException e) {
  76                         throw new JcrException("Cannot proxy " + path, e);
  77                 } finally {
  78                         if (nodeClient == null)
  79                                 JcrUtils.logoutQuietly(clientSession);
  80                 }
  81         }
  82
  83         protected synchronized Node retrieveAndSave(String path) {
  84                 try {
  85                         Node node = retrieve(jcrAdminSession, path);
  86                         if (node == null)
  87                                 return null;
  88                         jcrAdminSession.save();
  89                         return node;
  90                 } catch (RepositoryException e) {
  91                         JcrUtils.discardQuietly(jcrAdminSession);
  92                         throw new JcrException("Cannot retrieve and save " + path, e);
  93                 } finally {
  94                         notifyAll();
  95                 }
  96         }
  97
  98         /** Session is not saved */
  99         protected synchronized Node proxyUrl(Session session, String remoteUrl, String path) throws RepositoryException {
 100                 Node node = null;
 101                 if (session.itemExists(path)) {
 102                         // throw new ArgeoJcrException("Node " + path + " already exists");
 103                 }
 104                 try (InputStream in = new URL(remoteUrl).openStream()) {
 105                         // URL u = new URL(remoteUrl);
 106                         // in = u.openStream();
 107                         node = importFile(session, path, in);
 108                 } catch (IOException e) {
 109                         if (log.isDebugEnabled()) {
 110                                 log.debug("Cannot read " + remoteUrl + ", skipping... " + e.getMessage());
 111                                 // log.trace("Cannot read because of ", e);
 112                         }
 113                         JcrUtils.discardQuietly(session);
 114                         // } finally {
 115                         // IOUtils.closeQuietly(in);
 116                 }
 117                 return node;
 118         }
 119
 120         protected synchronized Node importFile(Session session, String path, InputStream in) throws RepositoryException {
 121                 Binary binary = null;
 122                 try {
 123                         Node content = null;
 124                         Node node = null;
 125                         if (!session.itemExists(path)) {
 126                                 node = JcrUtils.mkdirs(session, path, NodeType.NT_FILE, NodeType.NT_FOLDER, false);
 127                                 content = node.addNode(Node.JCR_CONTENT, NodeType.NT_UNSTRUCTURED);
 128                         } else {
 129                                 node = session.getNode(path);
 130                                 content = node.getNode(Node.JCR_CONTENT);
 131                         }
 132                         binary = session.getValueFactory().createBinary(in);
 133                         content.setProperty(Property.JCR_DATA, binary);
 134                         JcrUtils.updateLastModifiedAndParents(node, null, true);
 135                         return node;
 136                 } finally {
 137                         JcrUtils.closeQuietly(binary);
 138                 }
 139         }
 140
 141         /** Whether the file should be updated. */
 142         protected Boolean shouldUpdate(Session clientSession, String nodePath) {
 143                 return false;
 144         }
 145
 146         public void setJcrRepository(Repository jcrRepository) {
 147                 this.jcrRepository = jcrRepository;
 148         }
 149
 150         public void setProxyWorkspace(String localWorkspace) {
 151                 this.proxyWorkspace = localWorkspace;
 152         }
 153
 154 }