字段掩码

在 Google Ads API 中，更新是使用字段掩码完成的。字段掩码列出 您打算随更新而更改的所有字段，以及任何指定的字段 字段掩码范围外的其他字词，即使发送到服务器，也会被忽略。

FieldMaskUtil

推荐使用我们的内置字段掩码生成字段掩码 实用程序，它可让您通过修改的对象（而不是 从零开始构建它们

以下是一个更新广告系列的示例：

// Creates a Campaign object with the proper resource name and any other changes.
Campaign campaign =
    Campaign.newBuilder()
        .setResourceName(ResourceNames.campaign(customerId, campaignId))
        .setStatus(CampaignStatus.PAUSED)
        .build();

// Constructs an operation that will update the campaign, using the FieldMasks'
// allSetFieldsOf utility to derive the update mask. This mask tells the Google
// Ads API which attributes of the campaign you want to change.
CampaignOperation operation =
    CampaignOperation.newBuilder()
        .setUpdate(campaign)
        .setUpdateMask(FieldMasks.allSetFieldsOf(campaign))
        .build();

// Sends the operation in a mutate request.
MutateCampaignsResponse response =
    campaignServiceClient.mutateCampaigns(
        customerId.toString(), Collections.singletonList(operation));

此示例首先创建一个空的 Campaign 对象，然后设置其资源 以便 API 了解正在更新哪个广告系列。

该示例对广告系列使用 FieldMasks.allSetFieldsOf() 方法 自动生成枚举所有已设置字段的字段掩码。然后，您可以 将返回的掩码直接传递给 update 调用。

如果您需要使用现有对象更新一些字段，可以 按如下所示修改代码：

Campaign existingCampaign;

// Obtains existingCampaign from elsewhere.
...

// Creates a new campaign based off the existing campaign and updates the
// campaign by setting its status to paused.
Campaign campaignToUpdate =
    existingCampaign.toBuilder()
        .setStatus(CampaignStatus.PAUSED)
        .build();

// Constructs an operation that will update the campaign, using the FieldMasks'
// compare utility to derive the update mask. This mask tells the Google Ads API
// which attributes of the campaign you want to change.
CampaignOperation operation =
    CampaignOperation.newBuilder()
        .setUpdate(campaignToUpdate)
        .setUpdateMask(FieldMasks.compare(existingCampaign, campaignToUpdate))
        .build();

// Sends the operation in a mutate request.
MutateCampaignsResponse response =
    campaignServiceClient.mutateCampaigns(
        customerId.toString(), Collections.singletonList(operation));

要从头开始创建字段掩码，您首先需要创建一个 FieldMask 对象，然后将要更改的每个字段的名称添加到 对象。

FieldMask fieldMask =
    FieldMask.newBuilder()
        .addPaths("status")
        .addPaths("name")
        .build();

更新消息字段及其子字段

MESSAGE 字段可以包含子字段（例如 MaximizeConversions，其中包含三个： target_cpa_micros, cpc_bid_ceiling_micros 和 cpc_bid_floor_micros），也可以不将任何 （例如 ManualCpm）。

没有已定义子字段的消息字段

在更新未使用任何子字段定义的 MESSAGE 字段时，请使用 FieldMaskUtil ，以生成字段掩码（如上所述）。

包含已定义子字段的消息字段

更新使用不包含子字段的子字段定义的 MESSAGE 字段时 因此您必须手动设置 将每个可变的 MESSAGE 子字段添加到 FieldMask，类似于 上面的示例，它从头开始创建字段掩码。

一个常见的例子是，在未设置任何选项的情况下更新广告系列的出价策略 新出价策略的字段。以下示例演示了如何 更新广告系列以使用 MaximizeConversions出价策略 而不必为出价策略设置任何子字段。

在本例中，使用 allSetFieldsOf() 和 compare() 方法的 FieldMaskUtil 未达到预期目标。

以下示例将生成包含以下内容的字段掩码： maximize_conversions。但是，Google Ads API 不允许这种行为 防止意外清除字段 FieldMaskError.FIELD_HAS_SUBFIELDS 错误。

// Creates a campaign with the proper resource name and an empty
// MaximizeConversions field.
Campaign campaign = Campaign.newBuilder()
    .setResourceName(ResourceNames.campaign(customerId, campaignId))
    .setMaximizeConversions(MaximizeConversions.newBuilder().build())
    .build();

// Constructs an operation, using the FieldMasks' allSetFieldsOf utility to
// derive the update mask. The field mask will include 'maximize_conversions`,
// which will produce a FieldMaskError.FIELD_HAS_SUBFIELDS error.
CampaignOperation operation =
    CampaignOperation.newBuilder()
        .setUpdate(campaign)
        .setUpdateMask(FieldMasks.allSetFieldsOf(campaign))
        .build();

// Sends the operation in a mutate request that will result in a
// FieldMaskError.FIELD_HAS_SUBFIELDS error because empty MESSAGE fields cannot
// be included in a field mask.
MutateCampaignsResponse response =
    campaignServiceClient.mutateCampaigns(
        customerId.toString(), Collections.singletonList(operation));

以下示例演示了如何正确更新广告系列以使用 MaximizeConversions出价策略，但未设置任何子字段。

// Creates a Campaign object with the proper resource name.
Campaign campaign = Campaign.newBuilder()
    .setResourceName(ResourceNames.campaign(customerId, campaignId))
    .build();

// Creates a field mask from the existing campaign and adds all of the mutable
// fields (only one in this case) on the MaximizeConversions bidding strategy to
// the field mask. Because this field is included in the field mask but
// excluded from the campaign object, the Google Ads API will set the campaign's
// bidding strategy to a MaximizeConversions object without any of its subfields
// set.
FieldMask fieldMask = FieldMasks.allSetFieldsOf(campaign)
    .toBuilder()
    // Only include 'maximize_conversions.target_cpa_micros' in the field mask
    // as it is the only mutable subfield on MaximizeConversions when used as a
    // standard bidding strategy.
    //
    // Learn more about standard and portfolio bidding strategies here:
    // https://developers.google.com/google-ads/api/docs/campaigns/bidding/assign-strategies
    .addPaths("maximize_conversions.target_cpa_micros")
    .build();

// Creates an operation to update the campaign with the specified fields.
CampaignOperation operation =
    CampaignOperation.newBuilder()
        .setUpdate(campaign)
        .setUpdateMask(fieldMask)
        .build();

清除字段

某些字段是可以明确清除的。与上面的示例类似，您必须 明确地将这些字段添加到字段掩码中。例如，假设您有一个 广告系列，该广告系列采用的是MaximizeConversions出价策略，并且 “target_cpa_micros”字段的值大于 0。

系统会运行以下代码：不过，maximize_conversions.target_cpa_micros 因此也不会对 target_cpa_micros 字段：

// Creates a campaign with the proper resource name and a MaximizeConversions
// object with target_cpa_micros set to 0.
Campaign campaign =
    Campaign.newBuilder()
        .setResourceName(ResourceNames.campaign(customerId, campaignId))
        .setMaximizeConversions(
            MaximizeConversions.newBuilder().setTargetCpa(0).build())
        .setStatus(CampaignStatus.PAUSED)
        .build();

// Constructs an operation, using the FieldMasks' allSetFieldsOf utility to
// derive the update mask. However, the field mask will NOT include
// 'maximize_conversions.target_cpa_micros'.
CampaignOperation operation =
    CampaignOperation.newBuilder()
        .setUpdate(campaign)
        .setUpdateMask(FieldMasks.allSetFieldsOf(campaign))
        .build();

// Sends the operation in a mutate request that will succeed but will NOT update
// the 'target_cpa_micros' field because
// 'maximize_conversions.target_cpa_micros' was not included in the field mask.
MutateCampaignsResponse response =
    campaignServiceClient.mutateCampaigns(
        customerId.toString(), Collections.singletonList(operation));

下一个示例演示了如何正确清除 target_cpa_micros 字段（MaximizeConversions 出价策略）。

// Creates a Campaign object with the proper resource name.
Campaign campaign = Campaign.newBuilder()
    .setResourceName(ResourceNames.campaign(customerId, campaignId))
    .build();

// Constructs a field mask from the existing campaign and adds the
// 'maximize_conversions.target_cpa_micros' field to the field mask, which will
// clear this field from the bidding strategy without impacting any other fields
// on the bidding strategy.
FieldMask fieldMask = FieldMasks.allSetFieldsOf(campaign)
    .toBuilder()
    .addPaths("maximize_conversions.target_cpa_micros")
    .build();

// Creates an operation to update the campaign with the specified field.
CampaignOperation operation =
    CampaignOperation.newBuilder()
        .setUpdate(campaign)
        .setUpdateMask(fieldMask))
        .build();

请注意，上面的示例确实适用于 在 Google Ads API 中定义为 optional protocol buffers。 但自从使用 target_cpa_micros 不是 optional 字段，则“不正确”示例不会更新 清除 target_cpa 字段。