Java Callable -> 启动线程并等待

Question

我是新来的，如果我把这个放到错误的主题中，很抱歉？

我的问题:

class TaskEol implements Callable<ArrayList<Coordinates>> {
        ArrayList<CoordinatesEolEwp> coordinates = new ArrayList<Coordinates>();

        public ArrayList<Coordinates> call() throws Exception {
            new Thread (() -> {
                indicatorDatabaseAction.setVisible(true);
                coordinates = loadCoordinatesOutOfDatabase();
                indicatorDatabaseAction.setVisible(false);
            }).start();


            return coordinates;
        }
    }

如何等待数据库在返回对象之前将坐标写入对象中？

Answer 1

沿着这些线，其中 myCallable 是您的可调用内容，但没有 Thread 内容，即

public ArrayList<Coordinates> call() throws Exception {
    indicatorDatabaseAction.setVisible(true);
    coordinates = loadCoordinatesOutOfDatabase();
    indicatorDatabaseAction.setVisible(false);

    return coordinates;
}

然后...

ExecutorService e = Executors.newSingleThreadExecutor();
Future<ArrayList<Coordinates>> f = e.submit(myCallable);

// Note that Future.get() blocks until results are ready
ArrayList<Coordinates> coords = f.get();