Remove the concept of a TransferData abstract class (#2966)

The only type of thing that can be transferred now is a domain, so
there's no point in having this abstract class / redirection.

This does not include deletion of the contact-response-related XML
classes; that can come next.

core/src/main/java/google/registry/flows/domain/DomainTransferRequestFlow.java

@@ -76,7 +76,7 @@ import google.registry.model.reporting.HistoryEntry.HistoryEntryId;
 import google.registry.model.reporting.IcannReportingTypes.ActivityReportField;
 import google.registry.model.tld.Tld;
 import google.registry.model.transfer.DomainTransferData;
-import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
+import google.registry.model.transfer.DomainTransferData.TransferServerApproveEntity;
 import google.registry.model.transfer.TransferResponse.DomainTransferResponse;
 import google.registry.model.transfer.TransferStatus;
 import jakarta.inject.Inject;

core/src/main/java/google/registry/flows/domain/DomainTransferUtils.java

@@ -36,8 +36,7 @@ import google.registry.model.poll.PollMessage;
 import google.registry.model.reporting.HistoryEntry.HistoryEntryId;
 import google.registry.model.tld.Tld;
 import google.registry.model.transfer.DomainTransferData;
-import google.registry.model.transfer.TransferData;
-import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
+import google.registry.model.transfer.DomainTransferData.TransferServerApproveEntity;
 import google.registry.model.transfer.TransferResponse.DomainTransferResponse;
 import google.registry.model.transfer.TransferStatus;
 import google.registry.persistence.VKey;
@@ -51,7 +50,7 @@ import org.joda.time.DateTime;
  */
 public final class DomainTransferUtils {
 
-  /** Sets up {@link TransferData} for a domain with links to entities for server approval. */
+  /** Sets up {@link DomainTransferData} for a domain with links to entities for server approval. */
   public static DomainTransferData createPendingTransferData(
       String domainRepoId,
       Long historyId,
@@ -179,7 +178,7 @@ public final class DomainTransferUtils {
   /** Create a poll message for the gaining client in a transfer. */
   public static PollMessage createGainingTransferPollMessage(
       String targetId,
-      TransferData transferData,
+      DomainTransferData transferData,
       @Nullable DateTime extendedRegistrationExpirationTime,
       DateTime now,
       HistoryEntryId domainHistoryId) {
@@ -202,7 +201,7 @@ public final class DomainTransferUtils {
   /** Create a poll message for the losing client in a transfer. */
   public static PollMessage createLosingTransferPollMessage(
       String targetId,
-      TransferData transferData,
+      DomainTransferData transferData,
       @Nullable DateTime extendedRegistrationExpirationTime,
       HistoryEntryId domainHistoryId) {
     return new PollMessage.OneTime.Builder()
@@ -216,10 +215,10 @@ public final class DomainTransferUtils {
         .build();
   }
 
-  /** Create a {@link DomainTransferResponse} off of the info in a {@link TransferData}. */
+  /** Create a {@link DomainTransferResponse} off of the info in a {@link DomainTransferData}. */
   static DomainTransferResponse createTransferResponse(
       String targetId,
-      TransferData transferData,
+      DomainTransferData transferData,
       @Nullable DateTime extendedRegistrationExpirationTime) {
     return new DomainTransferResponse.Builder()
         .setDomainName(targetId)

core/src/main/java/google/registry/model/EppResource.java

@@ -34,7 +34,6 @@ import com.google.common.collect.ImmutableSet;
 import com.google.gson.annotations.Expose;
 import google.registry.config.RegistryConfig;
 import google.registry.model.eppcommon.StatusValue;
-import google.registry.model.transfer.TransferData;
 import google.registry.persistence.VKey;
 import google.registry.util.NonFinalForTesting;
 import jakarta.persistence.Access;
@@ -207,27 +206,6 @@ public abstract class EppResource extends UpdateAutoTimestampEntity implements B
   /** EppResources that are loaded via foreign keys should implement this marker interface. */
   public interface ForeignKeyedEppResource {}
 
-  /** An interface for resources that have transfer data. */
-  public interface ResourceWithTransferData<T extends TransferData> {
-    T getTransferData();
-
-    /**
-     * The time that this resource was last transferred.
-     *
-     * <p>Can be null if the resource has never been transferred.
-     */
-    DateTime getLastTransferTime();
-  }
-
-  /** An interface for builders of resources that have transfer data. */
-  public interface BuilderWithTransferData<
-      T extends TransferData, B extends BuilderWithTransferData<T, B>> {
-    B setTransferData(T transferData);
-
-    /** Set the time when this resource was transferred. */
-    B setLastTransferTime(DateTime lastTransferTime);
-  }
-
   /** Abstract builder for {@link EppResource} types. */
   public abstract static class Builder<T extends EppResource, B extends Builder<T, B>>
       extends GenericBuilder<T, B> {

core/src/main/java/google/registry/model/ResourceTransferUtils.java

@@ -29,7 +29,6 @@ import google.registry.model.poll.PendingActionNotificationResponse.DomainPendin
 import google.registry.model.poll.PollMessage;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.transfer.DomainTransferData;
-import google.registry.model.transfer.TransferData;
 import google.registry.model.transfer.TransferResponse;
 import google.registry.model.transfer.TransferResponse.DomainTransferResponse;
 import google.registry.model.transfer.TransferStatus;
@@ -79,7 +78,7 @@ public final class ResourceTransferUtils {
     if (!domain.getStatusValues().contains(StatusValue.PENDING_TRANSFER)) {
       return;
     }
-    TransferData oldTransferData = domain.getTransferData();
+    DomainTransferData oldTransferData = domain.getTransferData();
     tm().delete(oldTransferData.getServerApproveEntities());
     tm().put(
             new PollMessage.OneTime.Builder()
@@ -99,8 +98,8 @@ public final class ResourceTransferUtils {
    * Turn a domain into a builder with its pending transfer resolved.
    *
    * <p>This removes the {@link StatusValue#PENDING_TRANSFER} status, sets the {@link
-   * TransferStatus}, clears all the server-approve fields on the {@link TransferData}, and sets the
-   * expiration time of the last pending transfer to now.
+   * TransferStatus}, clears all the server-approve fields on the {@link DomainTransferData}, and
+   * sets the expiration time of the last pending transfer to now.
    */
   private static Domain.Builder resolvePendingTransfer(
       Domain domain, TransferStatus transferStatus, DateTime now) {
@@ -125,9 +124,9 @@ public final class ResourceTransferUtils {
    * Resolve a pending transfer by awarding it to the gaining client.
    *
    * <p>This removes the {@link StatusValue#PENDING_TRANSFER} status, sets the {@link
-   * TransferStatus}, clears all the server-approve fields on the {@link TransferData}, sets the new
-   * client id, and sets the last transfer time and the expiration time of the last pending transfer
-   * to now.
+   * TransferStatus}, clears all the server-approve fields on the {@link DomainTransferData}, sets
+   * the new client id, and sets the last transfer time and the expiration time of the last pending
+   * transfer to now.
    */
   public static Domain approvePendingTransfer(
       Domain domain, TransferStatus transferStatus, DateTime now) {
@@ -143,9 +142,9 @@ public final class ResourceTransferUtils {
    * Resolve a pending transfer by denying it.
    *
    * <p>This removes the {@link StatusValue#PENDING_TRANSFER} status, sets the {@link
-   * TransferStatus}, clears all the server-approve fields on the {@link TransferData}, sets the
-   * expiration time of the last pending transfer to now, sets the last EPP update time to now, and
-   * sets the last EPP update client id to the given client id.
+   * TransferStatus}, clears all the server-approve fields on the {@link DomainTransferData}, sets
+   * the expiration time of the last pending transfer to now, sets the last EPP update time to now,
+   * and sets the last EPP update client id to the given client id.
    */
   public static Domain denyPendingTransfer(
       Domain domain, TransferStatus transferStatus, DateTime now, String lastEppUpdateRegistrarId) {

core/src/main/java/google/registry/model/billing/BillingBase.java

@@ -26,7 +26,7 @@ import google.registry.model.UnsafeSerializable;
 import google.registry.model.annotations.IdAllocation;
 import google.registry.model.domain.DomainHistory;
 import google.registry.model.reporting.HistoryEntry.HistoryEntryId;
-import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
+import google.registry.model.transfer.DomainTransferData.TransferServerApproveEntity;
 import google.registry.persistence.VKey;
 import jakarta.persistence.Column;
 import jakarta.persistence.EnumType;

core/src/main/java/google/registry/model/domain/DomainBase.java

@@ -43,7 +43,6 @@ import com.google.common.collect.Sets;
 import com.google.gson.annotations.Expose;
 import google.registry.flows.ResourceFlowUtils;
 import google.registry.model.EppResource;
-import google.registry.model.EppResource.ResourceWithTransferData;
 import google.registry.model.billing.BillingRecurrence;
 import google.registry.model.domain.launch.LaunchNotice;
 import google.registry.model.domain.rgp.GracePeriodStatus;
@@ -96,8 +95,7 @@ import org.joda.time.Interval;
 @MappedSuperclass
 @Embeddable
 @Access(AccessType.FIELD)
-public class DomainBase extends EppResource
-    implements ResourceWithTransferData<DomainTransferData> {
+public class DomainBase extends EppResource {
 
   /** The max number of years that a domain can be registered for, as set by ICANN policy. */
   public static final int MAX_REGISTRATION_YEARS = 10;
@@ -319,12 +317,10 @@ public class DomainBase extends EppResource
     return Optional.ofNullable(autorenewEndTime.equals(END_OF_TIME) ? null : autorenewEndTime);
   }
 
-  @Override
   public DomainTransferData getTransferData() {
     return Optional.ofNullable(transferData).orElse(DomainTransferData.EMPTY);
   }
 
-  @Override
   public DateTime getLastTransferTime() {
     return lastTransferTime;
   }
@@ -605,7 +601,7 @@ public class DomainBase extends EppResource
 
   /** A builder for constructing {@link Domain}, since it is immutable. */
   public static class Builder<T extends DomainBase, B extends Builder<T, B>>
-      extends EppResource.Builder<T, B> implements BuilderWithTransferData<DomainTransferData, B> {
+      extends EppResource.Builder<T, B> {
 
     public Builder() {}
 
@@ -783,13 +779,11 @@ public class DomainBase extends EppResource
       return thisCastToDerived();
     }
 
-    @Override
     public B setTransferData(DomainTransferData transferData) {
       getInstance().transferData = transferData;
       return thisCastToDerived();
     }
 
-    @Override
     public B setLastTransferTime(DateTime lastTransferTime) {
       getInstance().lastTransferTime = lastTransferTime;
       return thisCastToDerived();

core/src/main/java/google/registry/model/host/HostBase.java

@@ -24,7 +24,6 @@ import static google.registry.util.DomainNameUtils.canonicalizeHostname;
 import com.google.common.collect.ImmutableSet;
 import google.registry.model.EppResource;
 import google.registry.model.domain.Domain;
-import google.registry.model.transfer.TransferData;
 import google.registry.persistence.VKey;
 import google.registry.persistence.converter.InetAddressSetUserType;
 import jakarta.persistence.Access;
@@ -41,8 +40,8 @@ import org.joda.time.DateTime;
 /**
  * A persistable Host resource including mutable and non-mutable fields.
  *
- * <p>A host's {@link TransferData} is stored on the superordinate domain. Non-subordinate hosts
- * don't carry a full set of TransferData; all they have is lastTransferTime.
+ * <p>A host's full transfer data is stored on the superordinate domain. Non-subordinate hosts don't
+ * carry a full set of TransferData; all they have is lastTransferTime.
  *
  * <p>This class deliberately does not include an {@link jakarta.persistence.Id} so that any
  * foreign-keyed fields can refer to the proper parent entity's ID, whether we're storing this in

core/src/main/java/google/registry/model/poll/PollMessage.java

@@ -32,14 +32,12 @@ import google.registry.model.domain.DomainRenewData;
 import google.registry.model.eppoutput.EppResponse.ResponseData;
 import google.registry.model.host.Host;
 import google.registry.model.host.HostHistory;
-import google.registry.model.poll.PendingActionNotificationResponse.ContactPendingActionNotificationResponse;
 import google.registry.model.poll.PendingActionNotificationResponse.DomainPendingActionNotificationResponse;
 import google.registry.model.poll.PendingActionNotificationResponse.HostPendingActionNotificationResponse;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.reporting.HistoryEntry.HistoryEntryId;
-import google.registry.model.transfer.TransferData.TransferServerApproveEntity;
+import google.registry.model.transfer.DomainTransferData.TransferServerApproveEntity;
 import google.registry.model.transfer.TransferResponse;
-import google.registry.model.transfer.TransferResponse.ContactTransferResponse;
 import google.registry.model.transfer.TransferResponse.DomainTransferResponse;
 import google.registry.persistence.VKey;
 import google.registry.persistence.WithVKey;
@@ -406,12 +404,8 @@ public abstract class PollMessage extends ImmutableObject
       if (pendingActionNotificationResponse != null) {
         // Promote the pending action notification response to its specialized type.
         if (contactId != null) {
-          pendingActionNotificationResponse =
-              ContactPendingActionNotificationResponse.create(
-                  pendingActionNotificationResponse.nameOrId.value,
-                  pendingActionNotificationResponse.getActionResult(),
-                  pendingActionNotificationResponse.getTrid(),
-                  pendingActionNotificationResponse.processedDate);
+          // Contacts are no longer supported
+          pendingActionNotificationResponse = null;
         } else if (domainName != null) {
           pendingActionNotificationResponse =
               DomainPendingActionNotificationResponse.create(
@@ -432,16 +426,8 @@ public abstract class PollMessage extends ImmutableObject
         // The transferResponse is currently an unspecialized TransferResponse instance, create the
         // appropriate subclass so that the value is consistently specialized
         if (contactId != null) {
-          transferResponse =
-              new ContactTransferResponse.Builder()
-                  .setContactId(contactId)
-                  .setGainingRegistrarId(transferResponse.getGainingRegistrarId())
-                  .setLosingRegistrarId(transferResponse.getLosingRegistrarId())
-                  .setTransferStatus(transferResponse.getTransferStatus())
-                  .setTransferRequestTime(transferResponse.getTransferRequestTime())
-                  .setPendingTransferExpirationTime(
-                      transferResponse.getPendingTransferExpirationTime())
-                  .build();
+          // Contacts are no longer supported
+          transferResponse = null;
         } else if (domainName != null) {
           transferResponse =
               new DomainTransferResponse.Builder()
@@ -488,9 +474,6 @@ public abstract class PollMessage extends ImmutableObject
 
         // Set identifier fields based on the type of the notification response.
         if (instance.pendingActionNotificationResponse
-            instanceof ContactPendingActionNotificationResponse) {
-          instance.contactId = instance.pendingActionNotificationResponse.nameOrId.value;
-        } else if (instance.pendingActionNotificationResponse
             instanceof DomainPendingActionNotificationResponse) {
           instance.domainName = instance.pendingActionNotificationResponse.nameOrId.value;
         } else if (instance.pendingActionNotificationResponse
@@ -507,9 +490,7 @@ public abstract class PollMessage extends ImmutableObject
                 .orElse(null);
 
         // Set the identifier according to the TransferResponse type.
-        if (instance.transferResponse instanceof ContactTransferResponse) {
-          instance.contactId = ((ContactTransferResponse) instance.transferResponse).getContactId();
-        } else if (instance.transferResponse instanceof DomainTransferResponse response) {
+        if (instance.transferResponse instanceof DomainTransferResponse response) {
           instance.domainName = response.getDomainName();
           instance.extendedRegistrationExpirationTime =
               response.getExtendedRegistrationExpirationTime();

core/src/main/java/google/registry/model/transfer/BaseTransferObject.java

@@ -25,7 +25,7 @@ import jakarta.xml.bind.annotation.XmlElement;
 import jakarta.xml.bind.annotation.XmlTransient;
 import org.joda.time.DateTime;
 
-/** Fields common to {@link TransferData} and {@link TransferResponse}. */
+/** Fields common to {@link DomainTransferData} and {@link TransferResponse}. */
 @XmlTransient
 @MappedSuperclass
 public abstract class BaseTransferObject extends ImmutableObject implements UnsafeSerializable {

core/src/main/java/google/registry/model/transfer/ContactTransferData.java

@@ -1,48 +0,0 @@
-// Copyright 2020 The Nomulus Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package google.registry.model.transfer;
-
-import jakarta.persistence.Embeddable;
-
-/** Transfer data for contact. */
-@Embeddable
-public class ContactTransferData extends TransferData {
-  public static final ContactTransferData EMPTY = new ContactTransferData();
-
-  @Override
-  public boolean isEmpty() {
-    return EMPTY.equals(this);
-  }
-
-  @Override
-  protected Builder createEmptyBuilder() {
-    return new Builder();
-  }
-
-  @Override
-  public Builder asBuilder() {
-    return new Builder(clone(this));
-  }
-
-  public static class Builder extends TransferData.Builder<ContactTransferData, Builder> {
-    /** Create a {@link Builder} wrapping a new instance. */
-    public Builder() {}
-
-    /** Create a {@link Builder} wrapping the given instance. */
-    private Builder(ContactTransferData instance) {
-      super(instance);
-    }
-  }
-}

core/src/main/java/google/registry/model/transfer/DomainTransferData.java

@@ -14,14 +14,20 @@
 
 package google.registry.model.transfer;
 
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.common.collect.ImmutableList.toImmutableList;
 import static google.registry.util.CollectionUtils.isNullOrEmpty;
+import static google.registry.util.CollectionUtils.nullToEmpty;
 
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import google.registry.model.Buildable;
 import google.registry.model.billing.BillingCancellation;
 import google.registry.model.billing.BillingEvent;
 import google.registry.model.billing.BillingRecurrence;
 import google.registry.model.domain.Period;
 import google.registry.model.domain.Period.Unit;
+import google.registry.model.eppcommon.Trid;
 import google.registry.model.poll.PollMessage;
 import google.registry.persistence.VKey;
 import google.registry.util.NullIgnoringCollectionBuilder;
@@ -36,9 +42,41 @@ import org.joda.time.DateTime;
 
 /** Transfer data for domain. */
 @Embeddable
-public class DomainTransferData extends TransferData {
+public class DomainTransferData extends BaseTransferObject implements Buildable {
   public static final DomainTransferData EMPTY = new DomainTransferData();
 
+  /** The transaction id of the most recent transfer request (or null if there never was one). */
+  @Embedded
+  @AttributeOverrides({
+    @AttributeOverride(
+        name = "serverTransactionId",
+        column = @Column(name = "transfer_server_txn_id")),
+    @AttributeOverride(
+        name = "clientTransactionId",
+        column = @Column(name = "transfer_client_txn_id"))
+  })
+  Trid transferRequestTrid;
+
+  @Column(name = "transfer_repo_id")
+  String repoId;
+
+  @Column(name = "transfer_history_entry_id")
+  Long historyEntryId;
+
+  // The pollMessageId1 and pollMessageId2 are used to store the IDs for gaining and losing poll
+  // messages in Cloud SQL.
+  //
+  // In addition, there may be a third poll message for the autorenew poll message on domain
+  // transfer if applicable.
+  @Column(name = "transfer_poll_message_id_1")
+  Long pollMessageId1;
+
+  @Column(name = "transfer_poll_message_id_2")
+  Long pollMessageId2;
+
+  @Column(name = "transfer_poll_message_id_3")
+  Long pollMessageId3;
+
   /**
    * The period to extend the registration upon completion of the transfer.
    *
@@ -107,15 +145,19 @@ public class DomainTransferData extends TransferData {
   @Column(name = "transfer_autorenew_poll_message_history_id")
   Long serverApproveAutorenewPollMessageHistoryId;
 
-  @Override
-  public Builder copyConstantFieldsToBuilder() {
-    return ((Builder) super.copyConstantFieldsToBuilder()).setTransferPeriod(transferPeriod);
-  }
-
   public Period getTransferPeriod() {
     return transferPeriod;
   }
 
+  public Long getHistoryEntryId() {
+    return historyEntryId;
+  }
+
+  @Nullable
+  public Trid getTransferRequestTrid() {
+    return transferRequestTrid;
+  }
+
   @Nullable
   public DateTime getTransferredRegistrationExpirationTime() {
     return transferredRegistrationExpirationTime;
@@ -141,12 +183,13 @@ public class DomainTransferData extends TransferData {
     return serverApproveAutorenewPollMessageHistoryId;
   }
 
-  @Override
   public ImmutableSet<VKey<? extends TransferServerApproveEntity>> getServerApproveEntities() {
     ImmutableSet.Builder<VKey<? extends TransferServerApproveEntity>> builder =
         new ImmutableSet.Builder<>();
-    builder.addAll(super.getServerApproveEntities());
     return NullIgnoringCollectionBuilder.create(builder)
+        .add(pollMessageId1 != null ? VKey.create(PollMessage.class, pollMessageId1) : null)
+        .add(pollMessageId2 != null ? VKey.create(PollMessage.class, pollMessageId2) : null)
+        .add(pollMessageId3 != null ? VKey.create(PollMessage.class, pollMessageId3) : null)
         .add(serverApproveBillingEvent)
         .add(serverApproveAutorenewEvent)
         .add(billingCancellationId)
@@ -154,16 +197,10 @@ public class DomainTransferData extends TransferData {
         .build();
   }
 
-  @Override
   public boolean isEmpty() {
     return EMPTY.equals(this);
   }
 
-  @Override
-  protected Builder createEmptyBuilder() {
-    return new Builder();
-  }
-
   @Override
   public Builder asBuilder() {
     return new Builder(clone(this));
@@ -186,7 +223,72 @@ public class DomainTransferData extends TransferData {
     }
   }
 
-  public static class Builder extends TransferData.Builder<DomainTransferData, Builder> {
+  /**
+   * Returns a fresh Builder populated only with the constant fields of this TransferData, i.e.
+   * those that are fixed and unchanging throughout the transfer process.
+   *
+   * <p>These fields are:
+   *
+   * <ul>
+   *   <li>transferRequestTrid
+   *   <li>transferRequestTime
+   *   <li>gainingClientId
+   *   <li>losingClientId
+   *   <li>transferPeriod
+   * </ul>
+   */
+  public Builder copyConstantFieldsToBuilder() {
+    return new Builder()
+        .setTransferPeriod(transferPeriod)
+        .setTransferRequestTrid(transferRequestTrid)
+        .setTransferRequestTime(transferRequestTime)
+        .setGainingRegistrarId(gainingClientId)
+        .setLosingRegistrarId(losingClientId);
+  }
+
+  /** Maps serverApproveEntities set to the individual fields. */
+  static void mapServerApproveEntitiesToFields(
+      Set<VKey<? extends TransferServerApproveEntity>> serverApproveEntities,
+      DomainTransferData transferData) {
+    if (isNullOrEmpty(serverApproveEntities)) {
+      transferData.pollMessageId1 = null;
+      transferData.pollMessageId2 = null;
+      transferData.pollMessageId3 = null;
+      return;
+    }
+    ImmutableList<Long> sortedPollMessageIds = getSortedPollMessageIds(serverApproveEntities);
+    if (!sortedPollMessageIds.isEmpty()) {
+      transferData.pollMessageId1 = sortedPollMessageIds.get(0);
+    }
+    if (sortedPollMessageIds.size() >= 2) {
+      transferData.pollMessageId2 = sortedPollMessageIds.get(1);
+    }
+    if (sortedPollMessageIds.size() >= 3) {
+      transferData.pollMessageId3 = sortedPollMessageIds.get(2);
+    }
+  }
+
+  /**
+   * Gets poll message IDs from the given serverApproveEntities and sorts the IDs in natural order.
+   */
+  private static ImmutableList<Long> getSortedPollMessageIds(
+      Set<VKey<? extends TransferServerApproveEntity>> serverApproveEntities) {
+    return nullToEmpty(serverApproveEntities).stream()
+        .filter(vKey -> PollMessage.class.isAssignableFrom(vKey.getKind()))
+        .map(vKey -> (long) vKey.getKey())
+        .sorted()
+        .collect(toImmutableList());
+  }
+
+  /**
+   * Marker interface for objects that are written in anticipation of a server approval, and
+   * therefore need to be deleted under any other outcome.
+   */
+  public interface TransferServerApproveEntity {
+    VKey<? extends TransferServerApproveEntity> createVKey();
+  }
+
+  public static class Builder extends BaseTransferObject.Builder<DomainTransferData, Builder> {
     /** Create a {@link Builder} wrapping a new instance. */
     public Builder() {}
 
@@ -195,6 +297,20 @@ public class DomainTransferData extends TransferData {
       super(instance);
     }
 
+    @Override
+    public DomainTransferData build() {
+      if (getInstance().pollMessageId1 != null) {
+        checkState(getInstance().repoId != null, "Repo id undefined");
+        checkState(getInstance().historyEntryId != null, "History entry undefined");
+      }
+      return super.build();
+    }
+
+    public Builder setTransferRequestTrid(Trid transferRequestTrid) {
+      getInstance().transferRequestTrid = transferRequestTrid;
+      return this;
+    }
+
     public Builder setTransferPeriod(Period transferPeriod) {
       getInstance().transferPeriod = transferPeriod;
       return this;
@@ -223,12 +339,13 @@ public class DomainTransferData extends TransferData {
       return this;
     }
 
-    @Override
     public Builder setServerApproveEntities(
         String repoId,
         Long historyId,
         ImmutableSet<VKey<? extends TransferServerApproveEntity>> serverApproveEntities) {
-      super.setServerApproveEntities(repoId, historyId, serverApproveEntities);
+      getInstance().repoId = repoId;
+      getInstance().historyEntryId = historyId;
+      mapServerApproveEntitiesToFields(serverApproveEntities, getInstance());
       mapBillingCancellationEntityToField(serverApproveEntities, getInstance());
       return this;
     }

core/src/main/java/google/registry/model/transfer/TransferData.java

@@ -1,205 +0,0 @@
-// Copyright 2017 The Nomulus Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package google.registry.model.transfer;
-
-import static com.google.common.base.Preconditions.checkState;
-import static com.google.common.collect.ImmutableList.toImmutableList;
-import static google.registry.util.CollectionUtils.isNullOrEmpty;
-import static google.registry.util.CollectionUtils.nullToEmpty;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableSet;
-import google.registry.model.Buildable;
-import google.registry.model.EppResource;
-import google.registry.model.eppcommon.Trid;
-import google.registry.model.poll.PollMessage;
-import google.registry.persistence.VKey;
-import google.registry.util.NullIgnoringCollectionBuilder;
-import jakarta.persistence.AttributeOverride;
-import jakarta.persistence.AttributeOverrides;
-import jakarta.persistence.Column;
-import jakarta.persistence.Embedded;
-import jakarta.persistence.MappedSuperclass;
-import java.util.Set;
-import javax.annotation.Nullable;
-
-/**
- * Common transfer data for {@link EppResource} types. Only applies to domains and contacts; hosts
- * are implicitly transferred with their superordinate domain.
- */
-@MappedSuperclass
-public abstract class TransferData extends BaseTransferObject implements Buildable {
-
-  /** The transaction id of the most recent transfer request (or null if there never was one). */
-  @Embedded
-  @AttributeOverrides({
-    @AttributeOverride(
-        name = "serverTransactionId",
-        column = @Column(name = "transfer_server_txn_id")),
-    @AttributeOverride(
-        name = "clientTransactionId",
-        column = @Column(name = "transfer_client_txn_id"))
-  })
-  Trid transferRequestTrid;
-
-  @Column(name = "transfer_repo_id")
-  String repoId;
-
-  @Column(name = "transfer_history_entry_id")
-  Long historyEntryId;
-
-  // The pollMessageId1 and pollMessageId2 are used to store the IDs for gaining and losing poll
-  // messages in Cloud SQL.
-  //
-  // In addition, there may be a third poll message for the autorenew poll message on domain
-  // transfer if applicable.
-  @Column(name = "transfer_poll_message_id_1")
-  Long pollMessageId1;
-
-  @Column(name = "transfer_poll_message_id_2")
-  Long pollMessageId2;
-
-  @Column(name = "transfer_poll_message_id_3")
-  Long pollMessageId3;
-
-  public abstract boolean isEmpty();
-
-  public Long getHistoryEntryId() {
-    return historyEntryId;
-  }
-
-  @Nullable
-  public Trid getTransferRequestTrid() {
-    return transferRequestTrid;
-  }
-
-  public ImmutableSet<VKey<? extends TransferServerApproveEntity>> getServerApproveEntities() {
-    return NullIgnoringCollectionBuilder.create(
-            new ImmutableSet.Builder<VKey<? extends TransferServerApproveEntity>>())
-        .add(pollMessageId1 != null ? VKey.create(PollMessage.class, pollMessageId1) : null)
-        .add(pollMessageId2 != null ? VKey.create(PollMessage.class, pollMessageId2) : null)
-        .add(pollMessageId3 != null ? VKey.create(PollMessage.class, pollMessageId3) : null)
-        .getBuilder()
-        .build();
-  }
-
-  @Override
-  public abstract Builder<?, ?> asBuilder();
-
-  protected abstract Builder<?, ?> createEmptyBuilder();
-
-  /**
-   * Returns a fresh Builder populated only with the constant fields of this TransferData, i.e.
-   * those that are fixed and unchanging throughout the transfer process.
-   *
-   * <p>These fields are:
-   *
-   * <ul>
-   *   <li>transferRequestTrid
-   *   <li>transferRequestTime
-   *   <li>gainingClientId
-   *   <li>losingClientId
-   *   <li>transferPeriod
-   * </ul>
-   */
-  public Builder<?, ?> copyConstantFieldsToBuilder() {
-    Builder<?, ?> newBuilder = createEmptyBuilder();
-    newBuilder
-        .setTransferRequestTrid(transferRequestTrid)
-        .setTransferRequestTime(transferRequestTime)
-        .setGainingRegistrarId(gainingClientId)
-        .setLosingRegistrarId(losingClientId);
-    return newBuilder;
-  }
-
-  /** Maps serverApproveEntities set to the individual fields. */
-  static void mapServerApproveEntitiesToFields(
-      Set<VKey<? extends TransferServerApproveEntity>> serverApproveEntities,
-      TransferData transferData) {
-    if (isNullOrEmpty(serverApproveEntities)) {
-      transferData.pollMessageId1 = null;
-      transferData.pollMessageId2 = null;
-      transferData.pollMessageId3 = null;
-      return;
-    }
-    ImmutableList<Long> sortedPollMessageIds = getSortedPollMessageIds(serverApproveEntities);
-    if (sortedPollMessageIds.size() >= 1) {
-      transferData.pollMessageId1 = sortedPollMessageIds.get(0);
-    }
-    if (sortedPollMessageIds.size() >= 2) {
-      transferData.pollMessageId2 = sortedPollMessageIds.get(1);
-    }
-    if (sortedPollMessageIds.size() >= 3) {
-      transferData.pollMessageId3 = sortedPollMessageIds.get(2);
-    }
-  }
-
-  /**
-   * Gets poll message IDs from the given serverApproveEntities and sorted the IDs in natural order.
-   */
-  private static ImmutableList<Long> getSortedPollMessageIds(
-      Set<VKey<? extends TransferServerApproveEntity>> serverApproveEntities) {
-    return nullToEmpty(serverApproveEntities).stream()
-        .filter(vKey -> PollMessage.class.isAssignableFrom(vKey.getKind()))
-        .map(vKey -> (long) vKey.getKey())
-        .sorted()
-        .collect(toImmutableList());
-  }
-
-  /** Builder for {@link TransferData} because it is immutable. */
-  public abstract static class Builder<T extends TransferData, B extends Builder<T, B>>
-      extends BaseTransferObject.Builder<T, B> {
-
-    /** Create a {@link Builder} wrapping a new instance. */
-    protected Builder() {}
-
-    /** Create a {@link Builder} wrapping the given instance. */
-    protected Builder(T instance) {
-      super(instance);
-    }
-
-    public B setTransferRequestTrid(Trid transferRequestTrid) {
-      getInstance().transferRequestTrid = transferRequestTrid;
-      return thisCastToDerived();
-    }
-
-    public B setServerApproveEntities(
-        String repoId,
-        Long historyId,
-        ImmutableSet<VKey<? extends TransferServerApproveEntity>> serverApproveEntities) {
-      getInstance().repoId = repoId;
-      getInstance().historyEntryId = historyId;
-      mapServerApproveEntitiesToFields(serverApproveEntities, getInstance());
-      return thisCastToDerived();
-    }
-
-    @Override
-    public T build() {
-      if (getInstance().pollMessageId1 != null) {
-        checkState(getInstance().repoId != null, "Repo id undefined");
-        checkState(getInstance().historyEntryId != null, "History entry undefined");
-      }
-      return super.build();
-    }
-  }
-
-  /**
-   * Marker interface for objects that are written in anticipation of a server approval, and
-   * therefore need to be deleted under any other outcome.
-   */
-  public interface TransferServerApproveEntity {
-    VKey<? extends TransferServerApproveEntity> createVKey();
-  }
-}

core/src/main/java/google/registry/rde/DomainToXjcConverter.java

@@ -23,7 +23,6 @@ import google.registry.model.domain.secdns.DomainDsData;
 import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.rde.RdeMode;
 import google.registry.model.transfer.DomainTransferData;
-import google.registry.model.transfer.TransferData;
 import google.registry.util.Idn;
 import google.registry.xjc.domain.XjcDomainNsType;
 import google.registry.xjc.domain.XjcDomainStatusType;
@@ -221,7 +220,7 @@ final class DomainToXjcConverter {
         && !Strings.isNullOrEmpty(model.getTransferData().getLosingRegistrarId());
   }
 
-  /** Converts {@link TransferData} to {@link XjcRdeDomainTransferDataType}. */
+  /** Converts {@link DomainTransferData} to {@link XjcRdeDomainTransferDataType}. */
   private static XjcRdeDomainTransferDataType convertTransferData(DomainTransferData model) {
     XjcRdeDomainTransferDataType bean = new XjcRdeDomainTransferDataType();
     bean.setTrStatus(

core/src/test/java/google/registry/flows/domain/DomainTransferFlowTestCase.java

@@ -41,7 +41,7 @@ import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.host.Host;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.tld.Tld;
-import google.registry.model.transfer.TransferData;
+import google.registry.model.transfer.DomainTransferData;
 import google.registry.model.transfer.TransferStatus;
 import google.registry.persistence.transaction.JpaTransactionManagerExtension;
 import org.joda.time.DateTime;
@@ -161,7 +161,8 @@ abstract class DomainTransferFlowTestCase<F extends Flow, R extends EppResource>
         .build();
   }
 
-  void assertTransferFailed(Domain domain, TransferStatus status, TransferData oldTransferData) {
+  void assertTransferFailed(
+      Domain domain, TransferStatus status, DomainTransferData oldTransferData) {
     assertAboutDomains()
         .that(domain)
         .doesNotHaveStatusValue(StatusValue.PENDING_TRANSFER)

core/src/test/java/google/registry/flows/domain/DomainTransferRejectFlowTest.java

@@ -54,7 +54,7 @@ import google.registry.model.poll.PollMessage;
 import google.registry.model.reporting.DomainTransactionRecord;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.tld.Tld;
-import google.registry.model.transfer.TransferData;
+import google.registry.model.transfer.DomainTransferData;
 import google.registry.model.transfer.TransferResponse;
 import google.registry.model.transfer.TransferStatus;
 import org.joda.time.DateTime;
@@ -90,7 +90,7 @@ class DomainTransferRejectFlowTest
     assertMutatingFlow(true);
     DateTime originalExpirationTime = domain.getRegistrationExpirationTime();
     ImmutableSet<GracePeriod> originalGracePeriods = domain.getGracePeriods();
-    TransferData originalTransferData = domain.getTransferData();
+    DomainTransferData originalTransferData = domain.getTransferData();
     runFlowAssertResponse(loadFile(expectedXmlFilename));
     // Transfer should have been rejected. Verify correct fields were set.
     domain = reloadResourceByForeignKey();

core/src/test/java/google/registry/model/transfer/DomainTransferDataTest.java

@@ -29,8 +29,8 @@ import org.joda.time.DateTime;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-/** Unit tests for {@link TransferData}. */
-public class TransferDataTest {
+/** Unit tests for {@link DomainTransferData}. */
+public class DomainTransferDataTest {
 
   private final DateTime now = DateTime.now(UTC);
 

db/src/main/resources/sql/er_diagram/brief_er_diagram.html

@@ -261,7 +261,7 @@ td.section {
     </tr>
     <tr>
      <td class="property_name">generated on</td>
-     <td class="property_value">2026-02-20 05:51:31</td>
+     <td class="property_value">2026-02-20 20:45:48</td>
     </tr>
     <tr>
      <td class="property_name">last flyway file</td>
@@ -273,7 +273,7 @@ td.section {
   <p>&nbsp;</p>
   <svg viewBox="0.00 0.00 4846.00 3765.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" id="erDiagram" style="overflow: hidden; width: 100%; height: 800px">
    <g id="graph0" class="graph" transform="scale(1 1) rotate(0) translate(4 3761)">
-    <title>SchemaCrawler_Diagram</title> <polygon fill="white" stroke="transparent" points="-4,4 -4,-3761 4842,-3761 4842,4 -4,4" /> <text text-anchor="start" x="4598" y="-29.8" font-family="Helvetica,sans-Serif" font-size="14.00">generated by</text> <text text-anchor="start" x="4681" y="-29.8" font-family="Helvetica,sans-Serif" font-size="14.00">SchemaCrawler 16.27.1</text> <text text-anchor="start" x="4597" y="-10.8" font-family="Helvetica,sans-Serif" font-size="14.00">generated on</text> <text text-anchor="start" x="4681" y="-10.8" font-family="Helvetica,sans-Serif" font-size="14.00">2026-02-20 05:51:31</text> <polygon fill="none" stroke="#888888" points="4594,-4 4594,-44 4830,-44 4830,-4 4594,-4" /> <!-- allocationtoken_a08ccbef -->
+    <title>SchemaCrawler_Diagram</title> <polygon fill="white" stroke="transparent" points="-4,4 -4,-3761 4842,-3761 4842,4 -4,4" /> <text text-anchor="start" x="4598" y="-29.8" font-family="Helvetica,sans-Serif" font-size="14.00">generated by</text> <text text-anchor="start" x="4681" y="-29.8" font-family="Helvetica,sans-Serif" font-size="14.00">SchemaCrawler 16.27.1</text> <text text-anchor="start" x="4597" y="-10.8" font-family="Helvetica,sans-Serif" font-size="14.00">generated on</text> <text text-anchor="start" x="4681" y="-10.8" font-family="Helvetica,sans-Serif" font-size="14.00">2026-02-20 20:45:48</text> <polygon fill="none" stroke="#888888" points="4594,-4 4594,-44 4830,-44 4830,-4 4594,-4" /> <!-- allocationtoken_a08ccbef -->
     <g id="node1" class="node">
      <title>allocationtoken_a08ccbef</title> <polygon fill="#e9c2f2" stroke="transparent" points="525.5,-1272 525.5,-1291 711.5,-1291 711.5,-1272 525.5,-1272" /> <text text-anchor="start" x="527.5" y="-1278.8" font-family="Helvetica,sans-Serif" font-weight="bold" font-style="italic" font-size="14.00">public."AllocationToken"</text> <polygon fill="#e9c2f2" stroke="transparent" points="711.5,-1272 711.5,-1291 785.5,-1291 785.5,-1272 711.5,-1272" /> <text text-anchor="start" x="746.5" y="-1277.8" font-family="Helvetica,sans-Serif" font-size="14.00">[table]</text> <text text-anchor="start" x="527.5" y="-1259.8" font-family="Helvetica,sans-Serif" font-weight="bold" font-style="italic" font-size="14.00">token</text> <text text-anchor="start" x="705.5" y="-1258.8" font-family="Helvetica,sans-Serif" font-size="14.00"> </text> <text text-anchor="start" x="713.5" y="-1258.8" font-family="Helvetica,sans-Serif" font-size="14.00">text not null</text> <text text-anchor="start" x="527.5" y="-1239.8" font-family="Helvetica,sans-Serif" font-size="14.00">domain_name</text> <text text-anchor="start" x="705.5" y="-1239.8" font-family="Helvetica,sans-Serif" font-size="14.00"> </text> <text text-anchor="start" x="713.5" y="-1239.8" font-family="Helvetica,sans-Serif" font-size="14.00">text</text> <text text-anchor="start" x="527.5" y="-1220.8" font-family="Helvetica,sans-Serif" font-size="14.00">redemption_domain_repo_id</text> <text text-anchor="start" x="705.5" y="-1220.8" font-family="Helvetica,sans-Serif" font-size="14.00"> </text> <text text-anchor="start" x="713.5" y="-1220.8" font-family="Helvetica,sans-Serif" font-size="14.00">text</text> <text text-anchor="start" x="527.5" y="-1201.8" font-family="Helvetica,sans-Serif" font-size="14.00">token_type</text> <text text-anchor="start" x="705.5" y="-1201.8" font-family="Helvetica,sans-Serif" font-size="14.00"> </text> <text text-anchor="start" x="713.5" y="-1201.8" font-family="Helvetica,sans-Serif" font-size="14.00">text</text> <polygon fill="none" stroke="#888888" points="524.5,-1195.5 524.5,-1292.5 786.5,-1292.5 786.5,-1195.5 524.5,-1195.5" />
     </g>

db/src/main/resources/sql/schema/db-schema.sql.generated

@@ -206,20 +206,20 @@
         tech_contact text,
         tld text,
         transfer_billing_cancellation_id bigint,
+        transfer_history_entry_id bigint,
+        transfer_poll_message_id_1 bigint,
+        transfer_poll_message_id_2 bigint,
+        transfer_poll_message_id_3 bigint,
+        transfer_repo_id text,
         transfer_billing_recurrence_id bigint,
         transfer_autorenew_poll_message_id bigint,
         transfer_autorenew_poll_message_history_id bigint,
         transfer_billing_event_id bigint,
         transfer_renew_period_unit text check (transfer_renew_period_unit in ('YEARS','MONTHS')),
         transfer_renew_period_value integer,
-        transfer_registration_expiration_time timestamp(6) with time zone,
-        transfer_history_entry_id bigint,
-        transfer_poll_message_id_1 bigint,
-        transfer_poll_message_id_2 bigint,
-        transfer_poll_message_id_3 bigint,
-        transfer_repo_id text,
         transfer_client_txn_id text,
         transfer_server_txn_id text,
+        transfer_registration_expiration_time timestamp(6) with time zone,
         transfer_gaining_registrar_id text,
         transfer_losing_registrar_id text,
         transfer_pending_expiration_time timestamp(6) with time zone,
@@ -278,20 +278,20 @@
         tech_contact text,
         tld text,
         transfer_billing_cancellation_id bigint,
+        transfer_history_entry_id bigint,
+        transfer_poll_message_id_1 bigint,
+        transfer_poll_message_id_2 bigint,
+        transfer_poll_message_id_3 bigint,
+        transfer_repo_id text,
         transfer_billing_recurrence_id bigint,
         transfer_autorenew_poll_message_id bigint,
         transfer_autorenew_poll_message_history_id bigint,
         transfer_billing_event_id bigint,
         transfer_renew_period_unit text check (transfer_renew_period_unit in ('YEARS','MONTHS')),
         transfer_renew_period_value integer,
-        transfer_registration_expiration_time timestamp(6) with time zone,
-        transfer_history_entry_id bigint,
-        transfer_poll_message_id_1 bigint,
-        transfer_poll_message_id_2 bigint,
-        transfer_poll_message_id_3 bigint,
-        transfer_repo_id text,
         transfer_client_txn_id text,
         transfer_server_txn_id text,
+        transfer_registration_expiration_time timestamp(6) with time zone,
         transfer_gaining_registrar_id text,
         transfer_losing_registrar_id text,
         transfer_pending_expiration_time timestamp(6) with time zone,