Futures.addCallback(ListenableFuture, new FutureCallback<Object>() {

  public void onSuccess(Object result) {
    System.out.printf("onSuccess with: %s%n", result);
  }

  public void onFailure(Throwable thrown) {
    System.out.printf("onFailure %s%n", thrown.getMessage());
  }
});

同時(shí)Guava中Futures對于Future擴(kuò)展還有：

transform：對于ListenableFuture的返回值進(jìn)行轉(zhuǎn)換。
allAsList：對多個(gè)ListenableFuture的合并，返回一個(gè)當(dāng)所有Future成功時(shí)返回多個(gè)Future返回值組成的List對象。注：當(dāng)其中一個(gè)Future失敗或者取消的時(shí)候，將會進(jìn)入失敗或者取消。
successfulAsList：和allAsList相似，唯一差別是對于失敗或取消的Future返回值用null代替。不會進(jìn)入失敗或者取消流程。
immediateFuture/immediateCancelledFuture：立即返回一個(gè)待返回值的ListenableFuture。
makeChecked: 將ListenableFuture 轉(zhuǎn)換成CheckedFuture。CheckedFuture 是一個(gè)ListenableFuture ，其中包含了多個(gè)版本的get 方法，方法聲明拋出檢查異常.這樣使得創(chuàng)建一個(gè)在執(zhí)行邏輯中可以拋出異常的Future更加容易
JdkFutureAdapters.listenInPoolThread(future): guava同時(shí)提供了將JDK Future轉(zhuǎn)換為ListenableFuture的接口函數(shù)。

下邊是一個(gè)對于Future的測試demo：

@Test
public void should_test_furture() throws Exception {
  ListeningExecutorService service = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(10));

  ListenableFuture future1 = service.submit(new Callable<Integer>() {
    public Integer call() throws InterruptedException {
      Thread.sleep(1000);
      System.out.println("call future 1.");
      return 1;
    }
  });

  ListenableFuture future2 = service.submit(new Callable<Integer>() {
    public Integer call() throws InterruptedException {
      Thread.sleep(1000);
      System.out.println("call future 2.");
  //    throw new RuntimeException("----call future 2.");
      return 2;
    }
  });

  final ListenableFuture allFutures = Futures.allAsList(future1, future2);

  final ListenableFuture transform = Futures.transform(allFutures, new AsyncFunction<List<Integer>, Boolean>() {
    @Override
    public ListenableFuture apply(List<Integer> results) throws Exception {
      return Futures.immediateFuture(String.format("success future:%d", results.size()));
    }
  });

  Futures.addCallback(transform, new FutureCallback<Object>() {

    public void onSuccess(Object result) {
      System.out.println(result.getClass());
      System.out.printf("success with: %s%n", result);
    }

    public void onFailure(Throwable thrown) {
      System.out.printf("onFailure%s%n", thrown.getMessage());
    }
  });

  System.out.println(transform.get());
}

官方資料主頁：https://awk.so/@code.google.com!/p/guava-libraries/wiki/ListenableFutureExplained

以上就是對Guava - 并行編程Futures 的資料整理，后續(xù)繼續(xù)補(bǔ)充相關(guān)資料謝謝大家對本站的支持！

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