Handler.java

private final class Handler implements HelloService.AsyncIface {
    @Override
    public void hello(String name, AsyncMethodCallback resultHandler) throws TException {
        setAsyncResult(resultHandler, CompletableFuture.completedFuture("hello"));
    }
}

public static <T> void setAsyncResult(AsyncMethodCallback<T> resultHandler,
                                      ListenableFuture<T> future) {
    Futures.addCallback(future, new FutureCallback<T>() {
        @Override
        public void onSuccess(@Nullable T result) {
            resultHandler.onComplete(result);
        }

        @Override
        public void onFailure(Throwable t) {
            if (t instanceof Exception) {
                resultHandler.onError((Exception) t);
            }
        }
    });
}

public static <T> void setAsyncResult(AsyncMethodCallback<T> resultHandler,
                                      CompletableFuture<T> future) {
    future.handle(voidFunction((result, thrown) -> {
        if (thrown != null) {
            resultHandler.onError((Exception) thrown);
        } else {
            resultHandler.onComplete(result);
        }
    }));
}

Sample.java

// Server side
private final class HelloServiceHandler implements HelloService.AsyncIface {
    @Override
    public void hello(String name, AsyncMethodCallback resultHandler) throws TException {
        resultHandler.onComplete(name);
    }
}

private void setup() {
    new ServerBuilder()
            .port(8080, SessionProtocol.HTTP)
            .serviceAt("/thrift", THttpService.of(new HelloServiceHandler()))
            .build()
            .start()
            .join();
}

// Client side
public CompletableFuture<String> hello(String name) throws TException {
    HelloService.AsyncIface async = Clients.newClient("http+tbinary://127.0.0.1:8080/thrift",
                                                      HelloService.AsyncIface.class);
    ThriftCompletableFuture<String> future = new ThriftCompletableFuture<>();
    async.hello(name, future);
    return future;
}