Class Feed

sdk/java/src/main/java/com/chain/api/Transaction.java:1074–1216

When used in conjunction with /list-transactions, Feeds can be used to receive notifications about transactions.

   * receive notifications about transactions.
   */
  public static class Feed {
    /**
     * Feed ID, automatically generated when a feed is created.
     */
    public String id;

    /**
     * An optional, user-supplied alias that can be used to uniquely identify
     * this feed.
     */
    public String alias;

    /**
     * The query filter used in /list-transactions.
     */
    public String filter;

    /**
     * Indicates the last transaction consumed by this feed.
     */
    public String after;

    private ListIterator<Transaction> txIter;
    private Transaction lastTx;

    /**
     * Creates a feed.
     *
     * @param client client object that makes requests to core
     * @param alias an alias which uniquely identifies this feed
     * @param filter a query filter which identifies which transactions this feed consumes
     * @return a feed object
     * @throws ChainException
     */
    public static Feed create(Client client, String alias, String filter) throws ChainException {
      Map<String, Object> req = new HashMap<>();
      req.put("alias", alias);
      req.put("filter", filter);
      req.put("client_token", UUID.randomUUID().toString());
      return client.request("create-transaction-feed", req, Feed.class);
    }

    /**
     * Retrieves a feed by ID.
     *
     * @param client client object that makes requests to core
     * @param id the feed id
     * @return a feed object
     * @throws ChainException
     */
    public static Feed getByID(Client client, String id) throws ChainException {
      Map<String, Object> req = new HashMap<>();
      req.put("id", id);
      return client.request("get-transaction-feed", req, Feed.class);
    }

    /**
     * Retrieves a feed by alias.