@Override
    public String getShortName() {
      if (this.shortName == null) {
        try {
          this.shortName = new HadoopKerberosName(this.name).getShortName();
        } catch (IOException ioe) {
          throw new IllegalArgumentException(
            "Illegal principal name " + this.name + ": " + ioe.toString(), ioe);
        }
      }
      return shortName;
    }
A temporary user class to instantiate User instance based on the name and groups.
hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessChecker.java