如何在等待回调中保存一个对象？

Question

我的代码调用服务器并获得 old-response。

然后我想进行轮询，直到从服务器（又名 new-response）收到不同的响应。

我使用 while 循环我可以保持 new-response 并在轮询后使用它。

如果我使用 awaitility 我怎样才能轻松获得 new-response？

这是我的代码：

public Version waitForNewConfig() throws Exception {
    Version oldVersion = deploymentClient.getCurrentConfigVersion(appName);
    await().atMost(1, MINUTES).pollInterval(5, SECONDS).until(newVersionIsReady(oldVersion));
    Version newVersion = deploymentClient.getCurrentConfigVersion(appName);

}

private Callable<Boolean> newVersionIsReady(Version oldVersion) {
    return new Callable<Boolean>() {
        public Boolean call() throws Exception {
            Version newVersion = deploymentClient.getCurrentConfigVersion(appName);

            return !oldVersion.equals(newVersion);
        }
    };
}

Answer 1

一种方法是制作一个记住它的专用 Callable 实现：

public Version waitForNewConfig() throws Exception {
    NewVersionIsReady newVersionIsReady = new NewVersionIsReady(deploymentClient.getCurrentConfigVersion(appName));
    await().atMost(1, MINUTES).pollInterval(5, SECONDS).until(newVersionIsReady);

    return newVersionIsReady.getNewVersion();
}

private final class NewVersionIsReady implements Callable<Boolean> {
    private final Version oldVersion;
    private Version newVersion;

    private NewVersionIsReady(Version oldVersion) {
        this.oldVersion = oldVersion;
    }

    public Boolean call() throws Exception {
        Version newVersion = deploymentClient.getCurrentConfigVersion(appName);

        return !oldVersion.equals(newVersion);
    }

    public Version getNewVersion() {
        return newVersion;
    }
}

另一种是将其存储在容器中（例如我使用数组）

public Version waitForNewConfig() throws Exception {
    Version[] currentVersionHolder = new Version[1];
    Version oldVersion = deploymentClient.getCurrentConfigVersion(appName);
    await().atMost(1, MINUTES).pollInterval(5, SECONDS).until(() -> {
        Version newVersion = deploymentClient.getCurrentConfigVersion(appName);
        currentVersionHolder[0] = newVersion;
        return !oldVersion.equals(newVersion);
    });

    return currentVersionHolder[0];
}

如果您还没有使用 java 8，您也可以使用匿名内部 class。

Answer 2

您可以使用ConditionFactory.until(Callable[T], Predicate[T])

例如：

Callable<MyObject> supplier = () -> queryForMyObject();
Predicate<MyObject> predicate = myObject -> myObject.getFooCount() > 3;

MyObject myObject = Awaitility.await()
   .atMost(1, TimeUnit.MINUTE)
   .pollInterval(Duration.ofSeconds(5))
   .until(supplier, predicate);

doStuff(myObject);

如何在等待回调中保存一个对象？

How can I save aside an object in awaitility callback?

java

multithreading

polling

awaitility