code: public CmsAliasEditValidationReply validateAliases(CmsAliasEditValidationRequest validationRequest) {
  
          List<CmsAliasTableRow> editedData = validationRequest.getEditedData();
          CmsAliasTableRow newEntry = validationRequest.getNewEntry();
          if (newEntry != null) {
              newEntry.setKey((new CmsUUID()).toString());
              editedData.add(newEntry);
  
          }
          CmsObject cms = m_cms;
          Locale locale = OpenCms.getWorkplaceManager().getWorkplaceLocale(cms);
          for (CmsAliasTableRow row : editedData) {
              row.clearErrors();
              validateSingleAliasRow(cms, row);
          }
          Set<String> foundAliasPaths = new HashSet<String>();
          Set<String> duplicateAliasPaths = new HashSet<String>();
          for (CmsAliasTableRow row : editedData) {
              String aliasPath = row.getAliasPath();
              if (foundAliasPaths.contains(aliasPath)) {
                  duplicateAliasPaths.add(aliasPath);
              }
              foundAliasPaths.add(aliasPath);
          }
          for (CmsAliasTableRow row : editedData) {
              if (duplicateAliasPaths.contains(row.getAliasPath())) {
                  if (row.getPathError() == null) {
                      row.setAliasError(messageDuplicateAliasPath(locale));
                      m_hasErrors = true;
                  }
              }
          }
          CmsAliasEditValidationReply result = new CmsAliasEditValidationReply();
          List<CmsAliasTableRow> changedRows = new ArrayList<CmsAliasTableRow>();
          for (CmsAliasTableRow row : editedData) {
              if (row.isChanged()) {
                  changedRows.add(row);
              }
          }
          if (newEntry != null) {
              changedRows.remove(newEntry);
          }
          result.setChangedRows(changedRows);
          result.setValidatedNewEntry(newEntry);
          return result;
      }
docs: Validates the alias data.<p>
  
  @param validationRequest an object containing the alias data to validate
  
  @return the validation result