フィールド マスク

// 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));

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));

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

// 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));

// 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();

// 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));

// 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();