code: private boolean isExistCmisObject(String path) {
          try {
              session.getObjectByPath(path);
              return true;
          }
          catch (CmisObjectNotFoundException e) {
              return false;
          }
      }
docs: Utility method for checking if CMIS object exists at defined path
  @param path path for object
  @return <code>true</code> if exists, <code>false</code> otherwise