code: public String getValue(String key) throws Exception{
  
      Object val = null;
  
      for (ObjectName oname: hadoopObjectNames) {
        try {
          val = mbsc.getAttribute(oname, key);
        } catch (AttributeNotFoundException anfe) {
          /*just go to the next */
          continue;
        } catch(ReflectionException re) {
          if (re.getCause() instanceof NoSuchMethodException) {
            continue;
          }
        }
        err("Info: key = " + key + "; val = " + val);
        break;
      }
  
      return (val == null) ? null : val.toString();
    }
docs: get single value by key