code: public static String getStringValue(String primaryKey) {
          String val = (String) CFG.get(primaryKey);
          if (val == null) {
              throw new SofaRpcRuntimeException("Not Found Key: " + primaryKey);
          } else {
              return val;
          }
      }
docs: Gets string value.
  
  @param primaryKey the primary key
  @return the string value