code: public static String[] getJournalHttpHosts(Configuration conf) {
      Collection<String> hosts = conf.getStringCollection(JournalConfigKeys.DFS_JOURNALNODE_HOSTS);
      int defaultHttpPort = JournalConfigKeys.DFS_JOURNALNODE_HTTP_PORT_DEFAULT;
  
      String[] httpAddresses = new String[hosts.size()];
      
      int i = 0;
      for (String address : hosts) {
        if (address.indexOf(":") < 0) {
          address += ":" + defaultHttpPort;
        }
        httpAddresses[i++] = address;
      }
      
      return httpAddresses;
    }
docs: Parse the DFS_JOURNALNODE_HOSTS to get the list of Journal Node Hosts
  
  This is used in JournalNode and QuorumJournalManager to talk to the
  Http servers of other JournalNodes.
  
  On the server side, the ports of the hosts are specified in the DFS_JOURNALNODE_HTTP_ADDRESS_KEY,
  so the ports in DFS_JOURNALNODE_HOSTS should be consistent with the port specified in
  DFS_JOURNALNODE_HTTP_ADDRESS_KEY, or left empty for DFS_JOURNALNODE_HTTP_PORT_DEFAULT.