code: private void setResourceInformation() {
  
          String sitePath = m_cms.getSitePath(m_resource);
          int pathEnd = sitePath.lastIndexOf('/') + 1;
          String baseName = sitePath.substring(pathEnd);
          m_sitepath = sitePath.substring(0, pathEnd);
          switch (CmsMessageBundleEditorTypes.BundleType.toBundleType(
              OpenCms.getResourceManager().getResourceType(m_resource).getTypeName())) {
              case PROPERTY:
                  String localeSuffix = CmsStringUtil.getLocaleSuffixForName(baseName);
                  if ((null != localeSuffix) && !localeSuffix.isEmpty()) {
                      baseName = baseName.substring(
                          0,
                          baseName.lastIndexOf(localeSuffix) - (1 /* cut off trailing underscore, too*/));
                      m_locale = CmsLocaleManager.getLocale(localeSuffix);
                  }
                  if ((null == m_locale) || !m_locales.contains(m_locale)) {
                      m_switchedLocaleOnOpening = true;
                      m_locale = m_locales.iterator().next();
                  }
                  break;
              case XML:
                  m_locale = OpenCms.getLocaleManager().getBestAvailableLocaleForXmlContent(
                      m_cms,
                      m_resource,
                      m_xmlBundle);
                  break;
              case DESCRIPTOR:
                  m_basename = baseName.substring(
                      0,
                      baseName.length() - CmsMessageBundleEditorTypes.Descriptor.POSTFIX.length());
                  m_locale = new Locale("en");
                  break;
              default:
                  throw new IllegalArgumentException(
                      Messages.get().container(
                          Messages.ERR_UNSUPPORTED_BUNDLE_TYPE_1,
                          CmsMessageBundleEditorTypes.BundleType.toBundleType(
                              OpenCms.getResourceManager().getResourceType(m_resource).getTypeName())).toString());
          }
          m_basename = baseName;
  
      }
docs: Extract site path, base name and locale from the resource opened with the editor.