How to use

Callbacks

in

com.nesscomputing.callback

/**
 * For every element, invoke the given callback.
 * Stops if {@link CallbackRefusedException} is thrown.
 */
@SafeVarargs
public static <T> void stream(Callback<T> callback, T... items) throws Exception
{
  stream(callback, Arrays.asList(items));
}

/**
 * Combine multiple callbacks into a single callback, preserving order.
 */
@SafeVarargs
public static <T> Callback<T> chain(Callback<T>... callbacks)
{
  return chain(Arrays.asList(callbacks));
}

  @Test
  public void testCallbackRefused() throws Exception
  {
    final List<Collection<String>> items = Lists.newArrayList();
    Callback<Collection<String>> callback = new Callback<Collection<String>>() {
      @Override
      public void call(Collection<String> item) throws Exception
      {
        if (items.size() > 1) {
          throw new CallbackRefusedException();
        }
        items.add(item);
      }
    };

    try (BatchingCallback<String> batcher = BatchingCallback.<String>batchInto(2, callback)) {
      Callbacks.stream(batcher, "a", "b", "c", "d", "e", "f", "g");
    }

    assertEquals(of(
        of("a", "b"),
        of("c", "d")
      ), items);
  }
}