Beispiel #1
0
  /**
   * Constructor. Initialises the servlet, reading the ontology model from static files and creating
   * a cleaner thread that removes obsolete sessions.
   */
  public LiberServletImpl() {
    System.out.println("Starting up");
    try {
      ontology = new OntologyReader(); // reads PolicyGrid ontologies
      //	ontology = new GeographyOntologyReader(); //reads geography ontology

      clean =
          new TimerTask() {
            public void run() { // 	Removes obsolete sessions from the map, running every 10 min.
              long time = new GregorianCalendar().getTimeInMillis();
              synchronized (userMap) {
                Iterator it = userMap.keySet().iterator();
                List<String> obsolete = new ArrayList<String>();
                while (it.hasNext()) {
                  String key = (String) it.next();
                  long timeDif = time - userMap.get(key).getLastUpdated();
                  if ((timeDif < 0)
                      || (timeDif > 3600000)) // if an hour has lapsed, or the next day has started
                  obsolete.add(key); // (let's just hope no-one starts using the tool at midnight)
                }
                for (int i = 0; i < obsolete.size(); i++) // then remove that session
                userMap.remove(obsolete.get(i));
              }
            }
          };
      Timer timer = new Timer();
      timer.schedule(clean, 0, 600000);

      Runtime r = Runtime.getRuntime();
      r.gc(); // FORCES GARBAGE COLLECTION
      r.runFinalization();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
Beispiel #2
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 /**
  * Returns an NL-expression of the given date.
  *
  * @param user User ID
  * @param input QueryDateValue containing restriction on date
  * @return String with nl-expression for date restriction (e.g. 'before 2007'), empty String if
  *     session expired or null if error occurred
  */
 public String getDateExpression(String user, QueryDateValue input) {
   if (!userMap.containsKey(user)) return "";
   try {
     return new SGDateNode(input.getDates()).getQueryNLExpression(input.getComparator());
   } catch (Exception e) {
     e.printStackTrace();
     return null;
   }
 }
Beispiel #3
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  /**
   * Creates a new session for the editing tool.
   *
   * @param user user id
   * @param project Project ID
   * @param resource Resource ID
   * @return String[] with user id and name
   */
  public String[] newSession(String user, String project, String resource) {
    try {
      LiberSession session = new LiberSession(ontology, user, project, resource, LiberSession.EDIT);
      userMap.put(user, session);

      Runtime r = Runtime.getRuntime();
      r.gc(); // FORCES GARBAGE COLLECTION
      r.runFinalization();
      return session.getUserDetails();
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
Beispiel #4
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  /**
   * Returns the values of resourceID for the properties specified in formInformation.
   *
   * @param user User ID
   * @param resourceID Resource ID
   * @param formInformation FormInfo[] specifying properties
   * @return String[] with values, null if session expired or error occurred
   */
  public String[] getDescriptionValues(String user, String resourceID, FormInfo[] formInformation) {
    try {
      if (!userMap.containsKey(user)) return null;

      LiberSession session = userMap.get(user);
      synchronized (session) {
        session.setLastUpdated();
        return session.getDescriptionValues(resourceID, formInformation);
      }
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
Beispiel #5
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  /**
   * Returns a tag cloud for the given property.
   *
   * @param user User ID
   * @param property Property name
   * @return TagCloud, null if session expired or error occurred
   */
  public TagCloud getTagCloud(String user, String property) {
    try {
      if (!userMap.containsKey(user)) return null;

      LiberSession session = userMap.get(user);
      synchronized (session) {
        session.setLastUpdated();
        TagCloud tc =
            new Folksonomy(user)
                .getTagCloud(session.getReader(), session.getReader().getProperty(property));
        return tc;
      }
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
Beispiel #6
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  /**
   * Initialises a new editing session.
   *
   * @param user user id
   * @param data Data provided about resource
   * @return AnchorInfo[] containing the feedback text.
   */
  public AnchorInfo[] initSession(String user, InstanceData data) {
    try {
      LiberSession session = userMap.get(user);

      Runtime r = Runtime.getRuntime();
      r.gc(); // FORCES GARBAGE COLLECTION
      r.runFinalization();

      synchronized (session) {
        session.setLastUpdated();
        return session.init(data); // initialise the session and return the text
      }
    } catch (Exception e) {
      e.printStackTrace();
      return new AnchorInfo[0];
    }
  }
Beispiel #7
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  /**
   * Returns an aggregated tag cloud for a set of properties.
   *
   * @param user User ID
   * @param properties String[] with property names
   * @return TagCloud, null if session expired or error occurred
   */
  public TagCloud getTagCloud(String user, String[] properties) {
    try {
      if (!userMap.containsKey(user)) return null;

      LiberSession session = userMap.get(user);
      synchronized (session) {
        session.setLastUpdated();
        List<OntProperty> list = new ArrayList<OntProperty>();
        for (int i = 0; i < properties.length; i++)
          list.add(session.getReader().getProperty(properties[i]));
        TagCloud tc = new Folksonomy(user).getTagCloud(session.getReader(), list);
        return tc;
      }
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
Beispiel #8
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  /**
   * Retrieves the values already added for this property and anchor
   *
   * @param user User ID
   * @param property Property name
   * @param anchor Unique ID of Anchor
   * @param key browsing session id (null if session type is EDIT)
   * @return String[] with values already added for this property and anchor, first element
   *     --EXPIRED-- if session expired, null if error occurred
   */
  public String[] getAddedValues(
      String user, String property, String anchor, int type, String key) {
    if (!userMap.containsKey(user)) {
      String[] result = new String[1];
      result[0] = "---EXPIRED---";
      return result;
    }

    try {
      LiberSession session = userMap.get(user);
      synchronized (session) {
        session.setLastUpdated();
        return session.getAddedValues(property, anchor, type, key);
      }
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
Beispiel #9
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  /**
   * Initialises a new query session, and returns the class hierarchy. This hierarchy is special
   * because it includes the number of instances of each type.
   *
   * @param user user id
   * @param roots root classes of the hierarchy (null to get complete hierarchy)
   * @return Hierarchy[] containing class hierarchy
   */
  public Hierarchy[] initSessionAndGetClassHierarchy(String user, String[] roots) {
    try {
      if (userMap.containsKey(user)) userMap.get(user).setLastUpdated();
      else userMap.put(user, new LiberSession(ontology, user, null, null, LiberSession.QUERY));

      LiberSession session = userMap.get(user);

      Runtime r = Runtime.getRuntime();
      r.gc(); // FORCES GARBAGE COLLECTION
      r.runFinalization();

      synchronized (session) {
        return session.getCountedClassHierarchy(roots);
      }
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
Beispiel #10
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  /**
   * Retrieves existing instances that qualify to be a target of this property, and instances that
   * already are a target of the property and anchor! Returns an array with first the range class
   * name, then those objects already in the range, then a 'null', and then all eligible objects.
   *
   * @param user user id
   * @param name property name
   * @param anchor Unique ID of Anchor
   * @param type session type
   * @param key browsing session id (null if session type is EDIT)
   * @return ExistingInstances, holds all necessary information about object that already are or
   *     could be in the range, empty if session expired, or null if error occurred.
   */
  public ExistingInstances getInstances(
      String user, String name, String anchor, int type, String key) {
    try {
      if (!userMap.containsKey(user)) {
        ExistingInstances result = new ExistingInstances();
        result.setRange(null, null);
        return result;
      }

      LiberSession session = userMap.get(user);
      synchronized (session) {
        session.setLastUpdated();
        ExistingInstances e = session.getRangeInstances(name, anchor, type, key);
        return e;
      }
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }
  }
Beispiel #11
0
  /**
   * Initialises a new browsing session, creating a new session for this user.
   *
   * @param user user id
   * @param resource Resource id
   * @param type Type of session (edit, query, browse)
   * @return AnchorInfo[] containing the feedback text.
   */
  public AnchorInfo[] initSession(String user, String resource, int type) {
    try {
      if (type == LiberSession.BROWSE) // make a new user session if this is the browse tab
      userMap.put(
            user, new LiberSession(ontology, user, null, resource.replaceAll("\"", ""), type));
      else if (!userMap.containsKey(user)) return null;

      LiberSession session = userMap.get(user);
      Runtime r = Runtime.getRuntime();
      r.gc(); // FORCES GARBAGE COLLECTION
      r.runFinalization();

      synchronized (session) {
        session.setLastUpdated();
        return session.init(
            resource.replaceAll("\"", "")); // initialise the session and return the text
      }
    } catch (Exception e) {
      e.printStackTrace();
      return new AnchorInfo[0];
    }
  }