如何在 Google People API 上使用同步令牌

Question

我真的找不到如何使用它的示例。

现在，我正在这样做：

    // Request 10 connections.
    ListConnectionsResponse response = peopleService.people().connections()
            .list("people/me")
            .setRequestSyncToken(true)
            .setPageSize(10)
            .setPersonFields("names,emailAddresses")
            .execute();

我对我的联系人进行了一些更改（添加、删除、更新），然后我这样做：

    // Request 10 connections.
    ListConnectionsResponse response2 = peopleService.people().connections()
            .list("people/me")
            .setSyncToken(response.getNextSyncToken())
            .setPageSize(10)
            .setPersonFields("names,emailAddresses")
            .execute();

但似乎我无法获得我之前所做的更改，即使我直接从 UI 进行更改也是如此。我很确定我以错误的方式使用了同步令牌。

更新（19/02/2020）：在这个例子中，我在第一个请求中调用了请求同步令牌的 API（我成功获取了联系人），暂停执行（通过断点），删除一个联系人并更新另一个联系人（从网页），恢复执行，然后我使用从上一次调用中提取的同步令牌再次调用 API。结果是由于某种原因没有进行任何更改：

   // Build a new authorized API client service.
    final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
    PeopleService peopleService = new PeopleService.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
            .setApplicationName(APPLICATION_NAME)
            .build();

    // Request 10 connections.
    ListConnectionsResponse response = peopleService.people().connections()
            .list("people/me")
            .setPageSize(10)
            .setPersonFields("names,emailAddresses")
            .setRequestSyncToken(true)
            .execute();

    // Print display name of connections if available.
    List<Person> connections = response.getConnections();
    if (connections != null && connections.size() > 0) {
        for (Person person : connections) {
            List<Name> names = person.getNames();
            if (names != null && names.size() > 0) {
                System.out.println("Name: " + person.getNames().get(0)
                        .getDisplayName());
            } else {
                System.out.println("No names available for connection.");
            }
        }
    } else {
        System.out.println("No connections found.");
    }
    // CORRECT: 2 CONTACTS PRINTED

    // CORRECT: THE SYNC TOKEN IS THERE
    String syncToken = response.getNextSyncToken();
    System.out.println("syncToken = "+syncToken);

    // I SETUP A BREAKPOINT BELOW, I DELETE ONE CONTACT AND EDIT ANOTHER AND THEN I RESUME THE EXECUTING
    // Request 10 connections.
    response = peopleService.people().connections()
            .list("people/me")
            .setPageSize(10)
            .setPersonFields("names,emailAddresses")
            .setSyncToken(syncToken)
            .execute();

    // Print display name of connections if available.
    connections = response.getConnections();
    if (connections != null && connections.size() > 0) {
        for (Person person : connections) {
            List<Name> names = person.getNames();
            if (names != null && names.size() > 0) {
                System.out.println("Name: " + person.getNames().get(0)
                        .getDisplayName());
            } else {
                System.out.println("No names available for connection.");
            }
        }
    } else {
        System.out.println("No connections found.");
    }
    // WRONG: I GET "NO CONNECTIONS FOUND"

Answer 1

我发现，在请求或设置同步令牌时，您必须迭代整个联系人以填充 nextSyncToken。

也就是说只要有nextPageToken(wink wink setPageSize(10))，同步令牌就不会被填充。

你可以：

A) 使用您当前的循环遍历所有联系人 分页，做任何你需要做的事情 迭代，并在最后一次调用后检索填充的 同步令牌。

B) 一次遍历所有联系人，使用最大值 页面大小为 2000 和单个 personField，检索 令牌，然后做任何你需要做的事情。请注意，如果 您期望用户拥有超过 2000 个 联系人，您仍然需要使用 下一个PageToken。

这里是一个同步循环的例子，改编自Synchronize Resources Efficiently。请注意，我通常使用 Python 客户端，因此此 Java 代码可能不是 100% 无错误：

private static void run() throws IOException {
    Request request = people_service.people().connections()
            .list("people/me")
            .setPageSize(10)
            .setPersonFields("names,emailAddresses");

    // Load the sync token stored from the last execution, if any. 
    // The syncSettingsDataStore is whatever you use for storage.
    String syncToken = syncSettingsDataStore.get(SYNC_TOKEN_KEY);

    String syncType = null;

    // Perform the appropiate sync
    if (syncToken == null) {
        // Perform a full sync
        request.setRequestSyncToken(true);
        syncType = "FULL";
    } else {
        // Try to perform an incremental sync.
        request.setSyncToken(syncToken);
        syncType = "INCREMENTAL";
    }

    String pageToken = null;
    ListConnectionsResponse response = null;
    List<Person> contacts = null;

    // Iterate over all the contacts, page by page.
    do {
        request.setPageToken(pageToken);

        try {
            response = request.execute();
        } catch (GoogleJsonResponseException e) {
            if (e.getStatusCode() == 410) {
                // A 410 status code, "Gone", indicates that the sync token is 
                // invalid/expired.
                // WARNING: The code is 400 in the Python client. I think the 
                //  Java client uses the correct code, but be on the lookout.

                // Clear the sync token.
                syncSettingsDataStore.delete(SYNC_TOKEN_KEY);
                // And anything else you need before re-syncing.
                dataStore.clear();
                // Restart
                run();
            } else {
              throw e;
            }
        }

        contacts = response.getItems();
        if (contacts.size() == 0) {
            System.out.println("No contacts to sync.");
        } else if (syncType == "FULL"){
            //do full sync for this page.
        } else if (syncType == "INCREMENTAL") {
            //do incremental sync for this page.
        } else {
            // What are you doing here???
        }

        pageToken = response.getNextPageToken();
    } while (pageToken != null);

    // Store the sync token from the last request for use at the next execution.
    syncSettingsDataStore.set(SYNC_TOKEN_KEY, response.getNextSyncToken());

    System.out.println("Sync complete.");
}