Beispiel #1
0
  private String transformContent(
      ServerRequestContext context, String xsltId, String xmlNotif, String action, String user)
      throws RegistryException {
    try {
      RepositoryItem repositoryItem =
          RepositoryManagerFactory.getInstance().getRepositoryManager().getRepositoryItem(xsltId);
      StreamSource xsltIn = new StreamSource(repositoryItem.getDataHandler().getInputStream());

      TransformerFactory tFactory = TransformerFactory.newInstance();
      Transformer transformer = tFactory.newTransformer(xsltIn);

      // transformer.setURIResolver(rm.getURIResolver());
      transformer.setErrorListener(
          new ErrorListener() {
            public void error(TransformerException exception) throws TransformerException {
              log.info(ServerResourceBundle.getInstance().getString("xsltError"), exception);
            }

            public void fatalError(TransformerException exception) throws TransformerException {
              log.error(ServerResourceBundle.getInstance().getString("xsltFatalError"), exception);
              throw exception;
            }

            public void warning(TransformerException exception) throws TransformerException {
              log.info(ServerResourceBundle.getInstance().getString("xsltWarning"), exception);
            }
          });

      // Set parameters
      transformer.setParameter("action", action);
      transformer.setParameter("user", user);
      transformer.setParameter(
          "registryBaseURL", RegistryProperties.getInstance().getProperty("omar.registry.baseurl"));

      ByteArrayInputStream bais = new ByteArrayInputStream(xmlNotif.getBytes("utf-8"));
      StreamSource inputSrc = new StreamSource(bais);

      // TODO: use file in case we have a large amount of data to transform?
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      StreamResult streamResult = new StreamResult(baos);

      transformer.transform(inputSrc, streamResult);

      return baos.toString("utf-8");
    } catch (Exception e) {
      log.error(
          ServerResourceBundle.getInstance().getString("message.prettyPrintNotificationFailure"),
          e);
      throw new RegistryException(e);
    }
  }
Beispiel #2
0
  protected void sendNotification(
      ServerRequestContext context,
      NotifyActionType notifyAction,
      NotificationType notification,
      AuditableEventType ae)
      throws RegistryException {
    log.trace("Sending email notification");

    String endpoint = notifyAction.getEndPoint();

    if ((endpoint == null) || !endpoint.startsWith("mailto:")) {
      throw new RegistryException(
          ServerResourceBundle.getInstance()
              .getString("message.emailNotificationWOmailto", new Object[] {endpoint}));
    }

    try {
      // get the body of the message , not yet defined !
      StringWriter sw = new StringWriter();
      Marshaller marshaller = BindingUtility.getInstance().rimFac.createMarshaller();
      marshaller.setProperty(javax.xml.bind.Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
      marshaller.marshal(notification, sw);

      // Now get the RegistryResponse as a String

      // Produce verbose response
      String notif = sw.toString();
      String action = ae.getEventType();
      String userId = ae.getUser();

      String userInfo;
      if (userId != null) {
        UserType user = (UserType) context.getRegistryObject(userId, "User_");
        userInfo =
            ServerResourceBundle.getInstance()
                .getString("message.user", new String[] {getUserInfo(user)});
      } else {
        userInfo = ServerResourceBundle.getInstance().getString("message.userUnknown");
      }

      SubscriptionType subscription =
          (SubscriptionType)
              context.getRegistryObject(notification.getSubscription(), "Subscription");
      String xsltId = getStyleSheetId(subscription);
      RepositoryItem repositoryItem = null;

      // empty string for notification property == use old format
      if (!"".equals(xsltId)) {
        // Dont use transform if there are any problems
        try {
          repositoryItem =
              RepositoryManagerFactory.getInstance()
                  .getRepositoryManager()
                  .getRepositoryItem(xsltId);
        } catch (Exception e) {
          log.warn(ServerResourceBundle.getInstance().getString("message.rawEmailNotification"), e);
        }
      }

      String contentType;
      String message;
      if (repositoryItem == null) {
        // No style sheet so skip the tranformation
        contentType = "text/xml";
        message = sw.toString();
      } else {
        contentType = "text/html";
        try {
          message = transformContent(context, xsltId, notif, action, userInfo);
        } catch (RegistryException e) {
          contentType = "text/xml";
          message = sw.toString();
        }
      }

      // set parameters and send the mail
      String subject =
          ServerResourceBundle.getInstance()
              .getString("message.registryNotification", new Object[] {notification.getId()});
      postMail(endpoint, message, subject, contentType);
    } catch (MessagingException e) {
      throw new RegistryException(e);
    } catch (JAXBException e) {
      throw new RegistryException(e);
    }
  }
/**
 * @author Farrukh S. Najmi
 *     <p>This class handles version management for RegistryObjects and RepositoryItems.
 */
public class VersionProcessor {

  public static BindingUtility bu = BindingUtility.getInstance();
  private static Log log = LogFactory.getLog(VersionProcessor.class);
  private QueryManager qm = QueryManagerFactory.getInstance().getQueryManager();
  private AuthenticationServiceImpl ac = AuthenticationServiceImpl.getInstance();
  private RepositoryManager rm = RepositoryManagerFactory.getInstance().getRepositoryManager();
  private HashSet versionableClassNameSet = new HashSet();
  private List versions;

  /** @associates <{org.freebxml.omar.server.persistence.PersistenceManagerImpl}> */
  PersistenceManager pm = PersistenceManagerFactory.getInstance().getPersistenceManager();;

  ServerRequestContext context = null;

  /** Creates a new instance of VersionManagerImpl */
  public VersionProcessor(ServerRequestContext context) {
    this.context = context;
    loadVersionableClasses();
  }

  public boolean needToVersionRegistryObject(RegistryObjectType ro) throws RegistryException {
    boolean needToVersion = true;

    BindingUtility bu = BindingUtility.getInstance();
    boolean newObject = false;

    try {
      needToVersion = isVersionableClass(ro);

      if (needToVersion) {
        HashMap slotsMap;
        // Honour dontVersion flag if specified on request
        if (!context.getRegistryRequestStack().empty()) {
          slotsMap = bu.getSlotsFromRequest(context.getCurrentRegistryRequest());
          if (slotsMap.containsKey(bu.CANONICAL_SLOT_LCM_DONT_VERSION)) {
            String val = (String) slotsMap.get(bu.CANONICAL_SLOT_LCM_DONT_VERSION);
            if (val.trim().equalsIgnoreCase("true")) {
              needToVersion = false;
            }
          }
        }

        // Honour dontVersion flag if specified on ro
        slotsMap = bu.getSlotsFromRegistryObject(ro);
        if (slotsMap.containsKey(bu.CANONICAL_SLOT_LCM_DONT_VERSION)) {
          String val = (String) slotsMap.get(bu.CANONICAL_SLOT_LCM_DONT_VERSION);
          if (val.trim().equalsIgnoreCase("true")) {
            needToVersion = false;
          }
        }
      }

      // TODO:
      // Need to investigate case where not versioning and it is a new object.
      // Need unit test for this case.
      if (needToVersion) {
        versions = getAllRegistryObjectVersions(ro);

        if (versions.size()
            == 0) { // If there are any existing versions (ie. ro's with same LID) then we need to
          // version
          // This is a new ro and therefor need not be versioned
          needToVersion = false;
          newObject = true;
        }
      }

      // Must set versionName to match latest versionName if existing object
      // or set to version 1.1 if new object.
      if (!needToVersion) {
        RegistryObjectType lastVersion = getLatestVersionOfRegistryObject(ro);
        String versionName = null;
        if (lastVersion == null) {
          versionName = "1.1";
        } else {
          versionName = lastVersion.getVersionInfo().getVersionName();

          // Must bump up versionName for new objects
          if (newObject) {
            versionName = nextVersion(versionName);
          }
        }

        VersionInfoType versionInfo = ro.getVersionInfo();
        if (versionInfo == null) {
          versionInfo = bu.rimFac.createVersionInfoType();
          ro.setVersionInfo(versionInfo);
        }
        versionInfo.setVersionName(versionName);
        if (!context.getRegistryRequestStack().empty()) {
          setVersionInfoComment(versionInfo);
        }
      }
    } catch (JAXBException e) {
      throw new RegistryException(e);
    }

    return needToVersion;
  }

  private void setVersionInfoComment(VersionInfoType versionInfo) {
    String requestComment = context.getCurrentRegistryRequest().getComment();
    if (versionInfo.getComment() == null && requestComment != null) {
      versionInfo.setComment(requestComment);
    }
  }

  public void checkRegistryObjectLid(RegistryObjectType ro) throws RegistryException {
    String id = ro.getId();
    String lid = ro.getLid();

    String existingObjectLid = (String) context.getIdToLidMap().get(id);

    // Assign lid if not specified, validate lid if specified
    if (existingObjectLid != null) {
      if (lid == null) {
        ro.setLid(existingObjectLid);
      } else {
        // Validate that lid matches existing objects lid
        if (!lid.equals(existingObjectLid)) {
          throw new RegistryException(
              ServerResourceBundle.getInstance()
                  .getString("message.idDoesNotMatch", new Object[] {lid, existingObjectLid, id}));
        }
      }
    } else {
      checkRegistryObjectLidOnNewObject(ro);
    }
  }

  public void checkRegistryObjectLidOnNewObject(RegistryObjectType ro) throws RegistryException {
    String id = ro.getId();
    String lid = ro.getLid();

    // Object does not exists already
    if (lid == null) {
      ro.setLid(ro.getId());
    }
  }

  public boolean needToVersionRepositoryItem(ExtrinsicObjectType eo, RepositoryItem riNew)
      throws RegistryException {
    boolean needToVersion = true;

    try {
      // dontVersion eo imples dontVersion ro
      needToVersion = needToVersionRegistryObject(eo);

      if (needToVersion) {
        // This is an existing object not a newly submitted object
        // See if repository item has changed or not.
        HashMap slotsMap;

        // Honour dontVersion flag if specified on request
        if (!context.getRegistryRequestStack().empty()) {
          slotsMap = bu.getSlotsFromRequest(context.getCurrentRegistryRequest());
          if (slotsMap.containsKey(bu.CANONICAL_SLOT_LCM_DONT_VERSION_CONTENT)) {
            String val = (String) slotsMap.get(bu.CANONICAL_SLOT_LCM_DONT_VERSION_CONTENT);
            if (val.trim().equalsIgnoreCase("true")) {
              needToVersion = false;
            }
          }
        }

        // Honour dontVersion flag if specified on ro
        slotsMap = bu.getSlotsFromRegistryObject(eo);
        if (slotsMap.containsKey(bu.CANONICAL_SLOT_LCM_DONT_VERSION_CONTENT)) {
          String val = (String) slotsMap.get(bu.CANONICAL_SLOT_LCM_DONT_VERSION_CONTENT);
          if (val.trim().equalsIgnoreCase("true")) {
            needToVersion = false;
          }
        }
      }

      if (needToVersion) {
        if (riNew == null) {
          needToVersion = false;
          return needToVersion;
        } else {
          RepositoryItem riOld = null;

          try {
            riOld = rm.getRepositoryItem(eo.getId());
          } catch (RepositoryItemNotFoundException e) {
            // It is possible that there is no RepositoryItem yet.
            // Ignore the exception.
          } catch (ObjectNotFoundException e) {
            // It is possible that there is no RepositoryItem yet.
            // Ignore the exception.
          }

          if (riOld == null) {
            needToVersion = false;
          } else {
            if (repositoryItemsAreIdentical(riOld, riNew)) {
              needToVersion = false;
            }
          }
        }
      }

      // Must set contentVersionName to match latest versionName if existing object
      // or set to version 1.1 if new object.
      if (!needToVersion) {
        ExtrinsicObjectType lastVersion =
            (ExtrinsicObjectType) getLatestVersionOfRegistryObject(eo);

        VersionInfoType contentVersionInfo = eo.getContentVersionInfo();
        if (contentVersionInfo == null) {
          contentVersionInfo = bu.rimFac.createVersionInfoType();
        }

        if (lastVersion == null) {
          // This is the first ExtrinsicObject version.
          if (riNew != null) {
            // This is the first RepositoryItem version. Make sure versionName is "1.1"
            contentVersionInfo.setVersionName("1.1");
          } else {
            // No repository item means that the contentVersionInfo MUST be set to null
            contentVersionInfo = null;
          }
        } else {
          // This is not the first ExtrinsicObject version.
          // Note that contentversionName is set even if no RI is submitted since
          // it is OK to update just the EO and have new version use last version of RO

          VersionInfoType lastContentVersionInfo = lastVersion.getContentVersionInfo();

          if (lastContentVersionInfo == null) {
            // Previous version had no repository item
            String lastContentVersionName = rm.getLatestVersionName(context, eo.getLid());
            if (lastContentVersionName != null) {
              contentVersionInfo.setVersionName(lastContentVersionName);
            } else {
              contentVersionInfo.setVersionName("1.1");
            }
          } else {
            // Previous version had a repository item
            // Use the last contentVersionName
            contentVersionInfo.setVersionName(lastContentVersionInfo.getVersionName());
          }
        }
        eo.setContentVersionInfo(contentVersionInfo);
      }

    } catch (JAXBException e) {
      throw new RegistryException(e);
    }

    return needToVersion;
  }

  /**
   * Creates a new version of the RepositoryItem associated with specified ExtrinsicObject. Note
   * that when the RepositoryItem is versioned its ExtrinsicObject must also be versioned.
   */
  public RepositoryItem createRepositoryItemVersion(ExtrinsicObjectType eo)
      throws RegistryException {
    RepositoryItem riNew = null;

    try {
      ExtrinsicObjectType eoNew = (ExtrinsicObjectType) createRegistryObjectVersion(eo);

      String latestContentVersionName = rm.getLatestVersionName(context, eo.getLid());
      String nextContentVersionName = nextVersion(latestContentVersionName);

      VersionInfoType nextContentVersionInfo = bu.rimFac.createVersionInfoType();
      nextContentVersionInfo.setVersionName(nextContentVersionName);

      // Set the contentComment from the submitted object's contentVersionInfo
      VersionInfoType submittedContentVersionInfo = eo.getContentVersionInfo();
      if (submittedContentVersionInfo != null) {
        nextContentVersionInfo.setComment(submittedContentVersionInfo.getComment());
      }

      // Update the eo contentVersionName to match newContentVersionName
      eoNew.setContentVersionInfo(nextContentVersionInfo);

      RepositoryItem riOld = (RepositoryItem) context.getRepositoryItemsMap().get(eo.getId());
      riNew = (RepositoryItem) riOld.clone();

      // A new version must have a unique id that matches its new ExtrinsicObject eoNew
      riNew.setId(eoNew.getId());

      // Now remeber in context.newRIVersionMap fro later replacement
      // Should we be using old or new eo.getId().
      // Maybe we dont need newRIVersionMap and newROVersionMap
      // Lets see how to just use existing idMap and other structures.
      context.getNewRIVersionMap().put(context.getRepositoryItemsMap().get(eo.getId()), riNew);
    } catch (CloneNotSupportedException e) {
      // This cannot happen
      throw new RegistryException(e);
    } catch (JAXBException e) {
      throw new RegistryException(e);
    }

    return riNew;
  }

  private List getAllRegistryObjectVersions(RegistryObjectType ro) throws RegistryException {
    if (versions == null) {
      ServerRequestContext queryContext = null;

      // Note: ORDER BY versionName DESC is not safe because String(1.10) < String(1.9)
      String query =
          "SELECT ro.* FROM "
              + Utility.getInstance().mapTableName(ro)
              + " ro WHERE ro.lid = '"
              + ro.getLid()
              + "'";

      try {
        AdhocQueryRequest queryRequest = bu.createAdhocQueryRequest(query);
        queryContext =
            new ServerRequestContext("VersionProcessor.getAllRegistryObjectVersions", queryRequest);

        queryContext.setUser(ac.registryOperator);

        AdhocQueryResponseType queryResp = qm.submitAdhocQuery(queryContext);
        versions = queryResp.getRegistryObjectList().getIdentifiable();
        queryContext.commit();
        queryContext = null;
      } catch (JAXBException e) {
        throw (new RegistryException(e));
      } catch (JAXRException e) {
        throw (new RegistryException(e));
      } finally {
        if (queryContext != null) {
          queryContext.rollback();
        }
      }
    }

    return (versions);
  }

  private RegistryObjectType getLatestVersionOfRegistryObject(RegistryObjectType ro)
      throws RegistryException {
    RegistryObjectType latestRO = null;

    // Call in case versions have not been initialized yet.
    getAllRegistryObjectVersions(ro);

    if (versions.size() == 0) {
      return null;
    }

    String latestVersion = null;
    for (Iterator it = versions.iterator(); it.hasNext(); ) {
      if (latestRO == null) {
        latestRO = (RegistryObjectType) it.next();
        latestVersion = latestRO.getVersionInfo().getVersionName();
        continue;
      }

      RegistryObjectType next = (RegistryObjectType) it.next();
      String nextVersion = next.getVersionInfo().getVersionName();

      if (compareVersions(nextVersion, latestVersion) > 0) {
        latestRO = next;
        latestVersion = latestRO.getVersionInfo().getVersionName();
      }
    }

    return latestRO;
  }

  // TODO: Consider replacing versions with idToVersionsMap as a performance optimization in future.
  private boolean isIdInVersions(String id) {
    RegistryObjectType ro = null;
    boolean foundId = false;

    if (versions != null) {
      Iterator iter = versions.iterator();

      while (iter.hasNext()) {
        ro = (RegistryObjectType) iter.next();

        if (id.equals(ro.getId())) {
          foundId = true;
          break;
        }
      }
    }

    return (foundId);
  }

  /**
   * Compares 2 version Strings, with major/minor versions separated by '.' Example: "1.10"
   *
   * @param v1 String for version 1.
   * @param v2 String for version 2.
   * @return int = 0 if params are equal; int > 0 if 1st is grater than 2nd; int < 0 if 2st is
   *     grater than 1nd.
   */
  public static int compareVersions(String v1, String v2) {
    String parts1[] = v1.split("\\.", 2);
    String parts2[] = v2.split("\\.", 2);

    int iCompare = Integer.parseInt(parts1[0]) - Integer.parseInt(parts2[0]);
    if (iCompare == 0) {
      // equal.. try subversions
      if (parts1.length == 1 && parts2.length == 1) {
        // really equal
        return 0;
      } else if (parts1.length == 1) {
        // other is bigger (v2)
        return -1;
      } else if (parts2.length == 1) {
        // other is bigger (v1)
        return +1;
      } else {
        // try subversions
        return compareVersions(parts1[1], parts2[1]);
      }
    } else {
      return iCompare;
    }
  }

  public RegistryObjectType createRegistryObjectVersion(RegistryObjectType ro)
      throws RegistryException {
    RegistryObjectType roNew = null;

    try {
      Utility util = Utility.getInstance();

      RegistryObjectType lastVersion = getLatestVersionOfRegistryObject(ro);
      String nextVersion = null;
      if (lastVersion == null) {
        nextVersion = "1.1";
      } else {
        nextVersion = nextVersion(lastVersion.getVersionInfo().getVersionName());
      }

      roNew = bu.cloneRegistryObject(ro);
      VersionInfoType nextVersionInfo = bu.rimFac.createVersionInfoType();
      nextVersionInfo.setVersionName(nextVersion);

      // Set the comment from the request comment (per the spec)
      if (!context.getRegistryRequestStack().empty()) {
        nextVersionInfo.setComment(context.getCurrentRegistryRequest().getComment());
      }

      roNew.setVersionInfo(nextVersionInfo);

      // A new version must have a unique id
      String id = ro.getId();
      String lid = ro.getLid();
      String idNew = id;

      // Only change id if it already exists in versions
      // Need to preserve client supplied id in the case where lid is an
      // existing lid but id is new
      if (isIdInVersions(id)) {
        // Make id of next version be lid with ":nextVersion" as suffix, if this id is already in
        // use in a version
        idNew = lid + ":" + nextVersion; // Utility.getInstance().createId();
        roNew.setId(idNew);

        // Add entry to idMap so old id and refs to it are mapped to idNew
        context.getIdMap().put(id, idNew);
      }

      // Add entry to context.newROVersionMap for later replacement
      context.getNewROVersionMap().put(ro, roNew);

      // Assign new ids to all composed RegistryObjects within roNew
      Set composedObjects = bu.getComposedRegistryObjects(roNew, -1);

      Iterator iter = composedObjects.iterator();
      while (iter.hasNext()) {
        RegistryObjectType composedObject = (RegistryObjectType) iter.next();

        // check for composed object if exist change the id and lid and
        // also update the idMap.
        if (objectExists(composedObject.getId())) {
          String oldId = composedObject.getId();
          String newId = oldId + ":" + nextVersion;
          composedObject.setId(newId);
          composedObject.setLid(newId);
          context.getIdMap().put(oldId, newId);
        }

        String composedId = composedObject.getId();
        String composedLid = composedObject.getLid();
        String composedIdNew = composedId;

        if (!util.isValidRegistryId(composedId)) { // Replace the id if it's not a valid ID already
          composedIdNew = util.createId();

          composedObject.setId(composedIdNew);

          // Add entry to idMap so old composedId and refs to it are mapped to composedIdNew
          context.getIdMap().put(composedId, composedIdNew);
        }

        if (composedLid == null || composedLid.trim().length() == 0) {
          composedObject.setLid(composedIdNew);
        }
        // Set the parent id of this composed object to point to the new parent
        bu.setParentIdForComposedObject(composedObject, idNew);
      }
    } catch (JAXRException e) {
      throw new RegistryException(e);
    } catch (JAXBException e) {
      throw new RegistryException(e);
    }
    return roNew;
  }

  /** Checks if object exist in registry. */
  private boolean objectExists(String id) throws RegistryException {
    boolean exists = false;
    try {
      RegistryObjectType ro = context.getRegistryObject(id, "RegistryObject", true);
      if (ro != null) {
        exists = true;
      }
    } catch (ObjectNotFoundException e) {
      // do nothing
    }
    return exists;
  }

  private String nextVersion(String lastVersion) {
    if ((lastVersion == null) || (lastVersion.length() == 0)) {
      lastVersion = "1.1";
    }

    String parts[] = lastVersion.split("\\.", 3);
    int majorVersion = (new Integer(parts[0])).intValue();
    int minorVersion = (new Integer(parts[1])).intValue();

    // TODO: check this. What if version has more than major/minor?
    if (parts.length > 2 && log.isWarnEnabled()) {
      log.warn(
          ServerResourceBundle.getInstance()
              .getString(
                  "message.IgnoringVersionInfromationAfterMajorMinorVersion",
                  new Object[] {parts[2]}));
    }

    // Increment version
    int newMinorVersion = minorVersion + 1;

    String nextVersion = parts[0] + "." + (new Integer(newMinorVersion)).toString();
    return nextVersion;
  }

  /*
   * Loads the list of versionable RIM classes from the property file during startup.
   */
  private void loadVersionableClasses() {
    String versionableClassList =
        RegistryProperties.getInstance()
            .getProperty("omar.server.lcm.VersionManager.versionableClassList");
    // System.err.println("loadVersionableClasses: versionableClassList='" + versionableClassList +
    // "'");
    if (versionableClassList != null) {
      StringTokenizer tokenizer = new StringTokenizer(versionableClassList, "|");

      while (tokenizer.hasMoreTokens()) {
        try {
          String versionableClassName = tokenizer.nextToken();
          versionableClassName =
              "org.oasis.ebxml.registry.bindings.rim." + versionableClassName + "Type";
          // System.err.println("    loadVersionableClasses: versionableClassName='" +
          // versionableClassName + "'");
          Class versionableClass = Class.forName(versionableClassName);
          versionableClassNameSet.add(versionableClass);
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    } else {
      // System.err.println(
      // "Registry has not defined the classes that will be versioned yet. This can be done by
      // setting the omar.server.lcm.VersionManager.versionableClassList property in omar.properties
      // file.");
    }
  }

  private boolean isVersionableClass(RegistryObjectType ro) {
    boolean isVersionable = false;

    // System.err.println("isVersionable entered. ro=" + ro.getClass().getName());
    Iterator iter = versionableClassNameSet.iterator();
    while (iter.hasNext()) {
      Class clazz = (Class) iter.next();
      // System.err.println("    isVersionable clazz=" + clazz.getName() + " isAssignableFrom = " +
      // clazz.isAssignableFrom(ro.getClass()));
      if (clazz.isAssignableFrom(ro.getClass())) {
        isVersionable = true;
        break;
      }
    }
    return isVersionable;
  }

  private boolean repositoryItemsAreIdentical(RepositoryItem ri1, RepositoryItem ri2) {
    DataHandler dh1 = ri1.getDataHandler();
    DataHandler dh2 = ri2.getDataHandler();

    return dh1.equals(dh2);
  }
}