diff --git a/java/google/registry/cron/TldFanoutAction.java b/java/google/registry/cron/TldFanoutAction.java
index 821f01983..49190c4a0 100644
--- a/java/google/registry/cron/TldFanoutAction.java
+++ b/java/google/registry/cron/TldFanoutAction.java
@@ -171,7 +171,7 @@ public final class TldFanoutAction implements Runnable {
     }
     for (String param : params.keySet()) {
       // TaskOptions.param() does not accept null values.
-      options.param(param, nullToEmpty((getFirst(params.get(param), null))));
+      options.param(param, nullToEmpty(getFirst(params.get(param), null)));
     }
     return options;
   }
diff --git a/java/google/registry/flows/contact/ContactCreateFlow.java b/java/google/registry/flows/contact/ContactCreateFlow.java
index a6ff170bc..0266db61e 100644
--- a/java/google/registry/flows/contact/ContactCreateFlow.java
+++ b/java/google/registry/flows/contact/ContactCreateFlow.java
@@ -31,7 +31,6 @@ import google.registry.flows.TransactionalFlow;
 import google.registry.flows.annotations.ReportingSpec;
 import google.registry.model.contact.ContactCommand.Create;
 import google.registry.model.contact.ContactResource;
-import google.registry.model.contact.ContactResource.Builder;
 import google.registry.model.domain.metadata.MetadataExtension;
 import google.registry.model.eppinput.ResourceCommand;
 import google.registry.model.eppoutput.CreateData.ContactCreateData;
@@ -71,19 +70,20 @@ public final class ContactCreateFlow implements TransactionalFlow {
     Create command = (Create) resourceCommand;
     DateTime now = ofy().getTransactionTime();
     verifyResourceDoesNotExist(ContactResource.class, targetId, now);
-    ContactResource newContact = new Builder()
-        .setContactId(targetId)
-        .setAuthInfo(command.getAuthInfo())
-        .setCreationClientId(clientId)
-        .setPersistedCurrentSponsorClientId(clientId)
-        .setRepoId(createRepoId(ObjectifyService.allocateId(), roidSuffix))
-        .setFaxNumber(command.getFax())
-        .setVoiceNumber(command.getVoice())
-        .setDisclose(command.getDisclose())
-        .setEmailAddress(command.getEmail())
-        .setInternationalizedPostalInfo(command.getInternationalizedPostalInfo())
-        .setLocalizedPostalInfo(command.getLocalizedPostalInfo())
-        .build();
+    ContactResource newContact =
+        new ContactResource.Builder()
+            .setContactId(targetId)
+            .setAuthInfo(command.getAuthInfo())
+            .setCreationClientId(clientId)
+            .setPersistedCurrentSponsorClientId(clientId)
+            .setRepoId(createRepoId(ObjectifyService.allocateId(), roidSuffix))
+            .setFaxNumber(command.getFax())
+            .setVoiceNumber(command.getVoice())
+            .setDisclose(command.getDisclose())
+            .setEmailAddress(command.getEmail())
+            .setInternationalizedPostalInfo(command.getInternationalizedPostalInfo())
+            .setLocalizedPostalInfo(command.getLocalizedPostalInfo())
+            .build();
     validateAsciiPostalInfo(newContact.getInternationalizedPostalInfo());
     validateContactAgainstPolicy(newContact);
     historyBuilder
diff --git a/java/google/registry/flows/contact/ContactUpdateFlow.java b/java/google/registry/flows/contact/ContactUpdateFlow.java
index facbf9338..34cb11733 100644
--- a/java/google/registry/flows/contact/ContactUpdateFlow.java
+++ b/java/google/registry/flows/contact/ContactUpdateFlow.java
@@ -39,7 +39,6 @@ import google.registry.flows.exceptions.ResourceHasClientUpdateProhibitedExcepti
 import google.registry.model.contact.ContactCommand.Update;
 import google.registry.model.contact.ContactCommand.Update.Change;
 import google.registry.model.contact.ContactResource;
-import google.registry.model.contact.ContactResource.Builder;
 import google.registry.model.contact.PostalInfo;
 import google.registry.model.domain.metadata.MetadataExtension;
 import google.registry.model.eppcommon.AuthInfo;
@@ -109,7 +108,7 @@ public final class ContactUpdateFlow implements TransactionalFlow {
         .setXmlBytes(null)  // We don't want to store contact details in the history entry.
         .setParent(Key.create(existingContact));
     checkSameValuesNotAddedAndRemoved(statusesToAdd, statusToRemove);
-    Builder builder = existingContact.asBuilder();
+    ContactResource.Builder builder = existingContact.asBuilder();
     Change change = command.getInnerChange();
     // The spec requires the following behaviors:
     //   * If you update part of a postal info, the fields that you didn't update are unchanged.
diff --git a/java/google/registry/flows/domain/DomainDeleteFlow.java b/java/google/registry/flows/domain/DomainDeleteFlow.java
index c4dbd007b..fff780979 100644
--- a/java/google/registry/flows/domain/DomainDeleteFlow.java
+++ b/java/google/registry/flows/domain/DomainDeleteFlow.java
@@ -62,7 +62,6 @@ import google.registry.flows.custom.EntityChanges;
 import google.registry.model.ImmutableObject;
 import google.registry.model.billing.BillingEvent;
 import google.registry.model.domain.DomainBase;
-import google.registry.model.domain.DomainBase.Builder;
 import google.registry.model.domain.GracePeriod;
 import google.registry.model.domain.fee.BaseFee.FeeType;
 import google.registry.model.domain.fee.Credit;
@@ -149,7 +148,7 @@ public final class DomainDeleteFlow implements TransactionalFlow {
     flowCustomLogic.afterValidation(
         AfterValidationParameters.newBuilder().setExistingDomain(existingDomain).build());
     ImmutableSet.Builder<ImmutableObject> entitiesToSave = new ImmutableSet.Builder<>();
-    Builder builder;
+    DomainBase.Builder builder;
     if (existingDomain.getStatusValues().contains(StatusValue.PENDING_TRANSFER)) {
       builder =
           denyPendingTransfer(existingDomain, TransferStatus.SERVER_CANCELLED, now, clientId)
diff --git a/java/google/registry/flows/domain/DomainRestoreRequestFlow.java b/java/google/registry/flows/domain/DomainRestoreRequestFlow.java
index 197e550e0..1dd507f4d 100644
--- a/java/google/registry/flows/domain/DomainRestoreRequestFlow.java
+++ b/java/google/registry/flows/domain/DomainRestoreRequestFlow.java
@@ -46,7 +46,6 @@ import google.registry.flows.annotations.ReportingSpec;
 import google.registry.model.ImmutableObject;
 import google.registry.model.billing.BillingEvent;
 import google.registry.model.billing.BillingEvent.OneTime;
-import google.registry.model.billing.BillingEvent.OneTime.Builder;
 import google.registry.model.billing.BillingEvent.Reason;
 import google.registry.model.domain.DomainBase;
 import google.registry.model.domain.DomainCommand.Update;
@@ -258,7 +257,7 @@ public final class DomainRestoreRequestFlow implements TransactionalFlow  {
         .build();
   }
 
-  private Builder prepareBillingEvent(HistoryEntry historyEntry, Money cost, DateTime now) {
+  private OneTime.Builder prepareBillingEvent(HistoryEntry historyEntry, Money cost, DateTime now) {
     return new BillingEvent.OneTime.Builder()
         .setTargetId(targetId)
         .setClientId(clientId)
diff --git a/java/google/registry/flows/domain/DomainTransferApproveFlow.java b/java/google/registry/flows/domain/DomainTransferApproveFlow.java
index 713cce753..d8881ae52 100644
--- a/java/google/registry/flows/domain/DomainTransferApproveFlow.java
+++ b/java/google/registry/flows/domain/DomainTransferApproveFlow.java
@@ -191,7 +191,7 @@ public final class DomainTransferApproveFlow implements TransactionalFlow {
             .setAutorenewPollMessage(Key.create(gainingClientAutorenewPollMessage))
             // Remove all the old grace periods and add a new one for the transfer.
             .setGracePeriods(
-                (billingEvent.isPresent())
+                billingEvent.isPresent()
                     ? ImmutableSet.of(
                         GracePeriod.forBillingEvent(GracePeriodStatus.TRANSFER, billingEvent.get()))
                     : ImmutableSet.of())
diff --git a/java/google/registry/flows/host/HostCreateFlow.java b/java/google/registry/flows/host/HostCreateFlow.java
index 504addb2e..47aee1798 100644
--- a/java/google/registry/flows/host/HostCreateFlow.java
+++ b/java/google/registry/flows/host/HostCreateFlow.java
@@ -45,7 +45,6 @@ import google.registry.model.eppoutput.CreateData.HostCreateData;
 import google.registry.model.eppoutput.EppResponse;
 import google.registry.model.host.HostCommand.Create;
 import google.registry.model.host.HostResource;
-import google.registry.model.host.HostResource.Builder;
 import google.registry.model.index.EppResourceIndex;
 import google.registry.model.index.ForeignKeyIndex;
 import google.registry.model.ofy.ObjectifyService;
@@ -119,7 +118,7 @@ public final class HostCreateFlow implements TransactionalFlow {
           : new UnexpectedExternalHostIpException();
     }
     HostResource newHost =
-        new Builder()
+        new HostResource.Builder()
             .setCreationClientId(clientId)
             .setPersistedCurrentSponsorClientId(clientId)
             .setFullyQualifiedHostName(targetId)
diff --git a/java/google/registry/flows/host/HostInfoFlow.java b/java/google/registry/flows/host/HostInfoFlow.java
index 692eceb24..3d602eab5 100644
--- a/java/google/registry/flows/host/HostInfoFlow.java
+++ b/java/google/registry/flows/host/HostInfoFlow.java
@@ -32,7 +32,6 @@ import google.registry.model.domain.DomainBase;
 import google.registry.model.eppcommon.StatusValue;
 import google.registry.model.eppoutput.EppResponse;
 import google.registry.model.host.HostInfoData;
-import google.registry.model.host.HostInfoData.Builder;
 import google.registry.model.host.HostResource;
 import google.registry.model.reporting.IcannReportingTypes.ActivityReportField;
 import google.registry.util.Clock;
@@ -72,7 +71,7 @@ public final class HostInfoFlow implements Flow {
     if (isLinked(Key.create(host), now)) {
       statusValues.add(StatusValue.LINKED);
     }
-    Builder hostInfoDataBuilder = HostInfoData.newBuilder();
+    HostInfoData.Builder hostInfoDataBuilder = HostInfoData.newBuilder();
     // Hosts transfer with their superordinate domains, so for hosts with a superordinate domain,
     // the client id, last transfer time, and pending transfer status need to be read off of it. If
     // there is no superordinate domain, the host's own values for these fields will be correct.
diff --git a/java/google/registry/gcs/GcsUtils.java b/java/google/registry/gcs/GcsUtils.java
index 0f5dd3424..a159bfb17 100644
--- a/java/google/registry/gcs/GcsUtils.java
+++ b/java/google/registry/gcs/GcsUtils.java
@@ -18,7 +18,6 @@ import static com.google.common.collect.Iterables.getLast;
 
 import com.google.appengine.tools.cloudstorage.GcsFileMetadata;
 import com.google.appengine.tools.cloudstorage.GcsFileOptions;
-import com.google.appengine.tools.cloudstorage.GcsFileOptions.Builder;
 import com.google.appengine.tools.cloudstorage.GcsFilename;
 import com.google.appengine.tools.cloudstorage.GcsService;
 import com.google.appengine.tools.cloudstorage.ListOptions;
@@ -113,7 +112,7 @@ public class GcsUtils {
 
   /** Determines most appropriate {@link GcsFileOptions} based on filename extension. */
   private static GcsFileOptions getOptions(GcsFilename filename) {
-    Builder builder = new GcsFileOptions.Builder().cacheControl("no-cache");
+    GcsFileOptions.Builder builder = new GcsFileOptions.Builder().cacheControl("no-cache");
     MediaType mediaType = EXTENSIONS.get(getLast(Splitter.on('.').split(filename.getObjectName())));
     if (mediaType != null) {
       builder = builder.mimeType(mediaType.type());
diff --git a/java/google/registry/keyring/kms/KmsConnectionImpl.java b/java/google/registry/keyring/kms/KmsConnectionImpl.java
index d4b469e99..c163263ea 100644
--- a/java/google/registry/keyring/kms/KmsConnectionImpl.java
+++ b/java/google/registry/keyring/kms/KmsConnectionImpl.java
@@ -47,11 +47,11 @@ class KmsConnectionImpl implements KmsConnection {
   @Inject
   KmsConnectionImpl(
       @Config("cloudKmsProjectId") String projectId,
-      @Config("cloudKmsKeyRing") String kmsKeyringName,
+      @Config("cloudKmsKeyRing") String kmsKeyRingName,
       Retrier retrier,
       CloudKMS kms) {
     this.projectId = projectId;
-    this.kmsKeyRingName = kmsKeyringName;
+    this.kmsKeyRingName = kmsKeyRingName;
     this.retrier = retrier;
     this.kms = kms;
   }
diff --git a/java/google/registry/model/EppResourceUtils.java b/java/google/registry/model/EppResourceUtils.java
index ea3be47c8..fa4faeae4 100644
--- a/java/google/registry/model/EppResourceUtils.java
+++ b/java/google/registry/model/EppResourceUtils.java
@@ -28,7 +28,6 @@ import com.googlecode.objectify.Result;
 import com.googlecode.objectify.cmd.Query;
 import com.googlecode.objectify.util.ResultNow;
 import google.registry.config.RegistryConfig;
-import google.registry.model.EppResource.Builder;
 import google.registry.model.EppResource.BuilderWithTransferData;
 import google.registry.model.EppResource.ForeignKeyedEppResource;
 import google.registry.model.EppResource.ResourceWithTransferData;
@@ -222,7 +221,7 @@ public final class EppResourceUtils {
   }
 
   /** Process an automatic transfer on a resource. */
-  public static <B extends Builder<?, B> & BuilderWithTransferData<B>>
+  public static <B extends EppResource.Builder<?, B> & BuilderWithTransferData<B>>
       void setAutomaticTransferSuccessProperties(B builder, TransferData transferData) {
     checkArgument(TransferStatus.PENDING.equals(transferData.getTransferStatus()));
     builder.removeStatusValue(StatusValue.PENDING_TRANSFER)
@@ -239,14 +238,15 @@ public final class EppResourceUtils {
 
   /**
    * Perform common operations for projecting an {@link EppResource} at a given time:
+   *
    * <ul>
    *   <li>Process an automatic transfer.
    * </ul>
    */
   public static <
-      T extends EppResource & ResourceWithTransferData,
-      B extends Builder<?, B> & BuilderWithTransferData<B>>
-          void projectResourceOntoBuilderAtTime(T resource, B builder, DateTime now) {
+          T extends EppResource & ResourceWithTransferData,
+          B extends EppResource.Builder<?, B> & BuilderWithTransferData<B>>
+      void projectResourceOntoBuilderAtTime(T resource, B builder, DateTime now) {
     TransferData transferData = resource.getTransferData();
     // If there's a pending transfer that has expired, process it.
     DateTime expirationTime = transferData.getPendingTransferExpirationTime();
@@ -289,7 +289,7 @@ public final class EppResourceUtils {
     // and returns it projected forward to exactly the desired timestamp, or null if the resource is
     // deleted at that timestamp.
     final Result<T> loadResult =
-        (isAtOrAfter(timestamp, resource.getUpdateAutoTimestamp().getTimestamp()))
+        isAtOrAfter(timestamp, resource.getUpdateAutoTimestamp().getTimestamp())
             ? new ResultNow<>(resource)
             : loadMostRecentRevisionAtTime(resource, timestamp);
     return () -> {
diff --git a/java/google/registry/model/ResourceTransferUtils.java b/java/google/registry/model/ResourceTransferUtils.java
index 017e57aa2..fcc90dd37 100644
--- a/java/google/registry/model/ResourceTransferUtils.java
+++ b/java/google/registry/model/ResourceTransferUtils.java
@@ -23,7 +23,6 @@ import static google.registry.model.ofy.ObjectifyService.ofy;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
-import google.registry.model.EppResource.Builder;
 import google.registry.model.EppResource.BuilderWithTransferData;
 import google.registry.model.EppResource.ForeignKeyedEppResource;
 import google.registry.model.EppResource.ResourceWithTransferData;
@@ -170,7 +169,7 @@ public final class ResourceTransferUtils {
    */
   public static <
           R extends EppResource & ResourceWithTransferData,
-          B extends Builder<R, B> & BuilderWithTransferData<B>>
+          B extends EppResource.Builder<R, B> & BuilderWithTransferData<B>>
       R approvePendingTransfer(R resource, TransferStatus transferStatus, DateTime now) {
     checkArgument(transferStatus.isApproved(), "Not an approval transfer status");
     B builder = resolvePendingTransfer(resource, transferStatus, now);
diff --git a/java/google/registry/model/domain/GracePeriod.java b/java/google/registry/model/domain/GracePeriod.java
index 27cd16d08..76c1b42b4 100644
--- a/java/google/registry/model/domain/GracePeriod.java
+++ b/java/google/registry/model/domain/GracePeriod.java
@@ -100,7 +100,8 @@ public class GracePeriod extends ImmutableObject {
        @Nullable Key<BillingEvent.Recurring> billingEventRecurring) {
     checkArgument((billingEventOneTime == null) || (billingEventRecurring == null),
         "A grace period can have at most one billing event");
-    checkArgument((billingEventRecurring != null) == (GracePeriodStatus.AUTO_RENEW.equals(type)),
+    checkArgument(
+        (billingEventRecurring != null) == GracePeriodStatus.AUTO_RENEW.equals(type),
         "Recurring billing events must be present on (and only on) autorenew grace periods");
     GracePeriod instance = new GracePeriod();
     instance.type = checkArgumentNotNull(type);
diff --git a/java/google/registry/model/eppinput/ResourceCommand.java b/java/google/registry/model/eppinput/ResourceCommand.java
index d0a7a67de..f6158f986 100644
--- a/java/google/registry/model/eppinput/ResourceCommand.java
+++ b/java/google/registry/model/eppinput/ResourceCommand.java
@@ -19,7 +19,7 @@ import static google.registry.util.CollectionUtils.nullToEmptyImmutableCopy;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
-import google.registry.model.Buildable.Builder;
+import google.registry.model.Buildable;
 import google.registry.model.EppResource;
 import google.registry.model.ImmutableObject;
 import google.registry.model.eppcommon.AuthInfo;
@@ -82,7 +82,7 @@ public interface ResourceCommand {
   }
 
   /** A create command, or the inner change (as opposed to add or remove) part of an update. */
-  interface ResourceCreateOrChange<B extends Builder<?>> {}
+  interface ResourceCreateOrChange<B extends Buildable.Builder<?>> {}
 
   /**
    * An update command for an {@link EppResource}.
diff --git a/java/google/registry/model/host/HostResource.java b/java/google/registry/model/host/HostResource.java
index 8e8d79ced..d00b94d7e 100644
--- a/java/google/registry/model/host/HostResource.java
+++ b/java/google/registry/model/host/HostResource.java
@@ -149,7 +149,7 @@ public class HostResource extends EppResource implements ForeignKeyedEppResource
         Optional.ofNullable(getLastSuperordinateChange()).orElse(getCreationTime());
     DateTime lastTransferOfCurrentSuperordinate =
         Optional.ofNullable(superordinateDomain.getLastTransferTime()).orElse(START_OF_TIME);
-    return (lastSuperordinateChange.isBefore(lastTransferOfCurrentSuperordinate))
+    return lastSuperordinateChange.isBefore(lastTransferOfCurrentSuperordinate)
         ? superordinateDomain.getLastTransferTime()
         : getLastTransferTime();
   }
diff --git a/java/google/registry/model/index/EppResourceIndexBucket.java b/java/google/registry/model/index/EppResourceIndexBucket.java
index bbd472394..5ccd703d6 100644
--- a/java/google/registry/model/index/EppResourceIndexBucket.java
+++ b/java/google/registry/model/index/EppResourceIndexBucket.java
@@ -41,7 +41,7 @@ public class EppResourceIndexBucket extends ImmutableObject {
   private static long getBucketIdFromEppResource(Key<? extends EppResource> resourceKey) {
     int numBuckets = getEppResourceIndexBucketCount();
     // IDs can't be 0, so add 1 to the hash.
-    return Hashing.consistentHash(resourceKey.getName().hashCode(), numBuckets) + 1;
+    return Hashing.consistentHash(resourceKey.getName().hashCode(), numBuckets) + 1L;
   }
 
   /** Gets a bucket key as a function of an EppResource to be indexed. */
diff --git a/java/google/registry/model/registrar/Registrar.java b/java/google/registry/model/registrar/Registrar.java
index b32208444..46bc37295 100644
--- a/java/google/registry/model/registrar/Registrar.java
+++ b/java/google/registry/model/registrar/Registrar.java
@@ -130,8 +130,10 @@ public class Registrar extends ImmutableObject implements Buildable, Jsonifiable
     /**
      * Predicate for validating IANA IDs for this type of registrar.
      *
-     * @see <a href="http://www.iana.org/assignments/registrar-ids/registrar-ids.txt">Registrar IDs</a>
+     * @see <a href="http://www.iana.org/assignments/registrar-ids/registrar-ids.txt">Registrar
+     *     IDs</a>
      */
+    @SuppressWarnings("ImmutableEnumChecker")
     private final Predicate<Long> ianaIdValidator;
 
     Type(Predicate<Long> ianaIdValidator) {
diff --git a/java/google/registry/rde/ContactResourceToXjcConverter.java b/java/google/registry/rde/ContactResourceToXjcConverter.java
index e9773097f..53bb40fcf 100644
--- a/java/google/registry/rde/ContactResourceToXjcConverter.java
+++ b/java/google/registry/rde/ContactResourceToXjcConverter.java
@@ -36,6 +36,7 @@ import google.registry.xjc.eppcom.XjcEppcomTrStatusType;
 import google.registry.xjc.rdecontact.XjcRdeContact;
 import google.registry.xjc.rdecontact.XjcRdeContactElement;
 import google.registry.xjc.rdecontact.XjcRdeContactTransferDataType;
+import java.util.Objects;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
 
@@ -101,7 +102,7 @@ final class ContactResourceToXjcConverter {
     //       required before an automated response action will be taken by
     //       the registry.  For all other status types, the value identifies
     //       the date and time when the request was completed.
-    if (model.getTransferData() != TransferData.EMPTY) {
+    if (!Objects.equals(model.getTransferData(), TransferData.EMPTY)) {
       bean.setTrnData(convertTransferData(model.getTransferData()));
     }
 
diff --git a/java/google/registry/rde/RdeResourceType.java b/java/google/registry/rde/RdeResourceType.java
index 31c58fda9..d22383ab1 100644
--- a/java/google/registry/rde/RdeResourceType.java
+++ b/java/google/registry/rde/RdeResourceType.java
@@ -17,12 +17,11 @@ package google.registry.rde;
 import static google.registry.model.rde.RdeMode.FULL;
 import static google.registry.model.rde.RdeMode.THIN;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSortedSet;
 import com.google.common.collect.Ordering;
 import google.registry.model.rde.RdeMode;
-import java.util.Collections;
 import java.util.EnumSet;
-import java.util.Set;
 
 /** Types of objects that get embedded in an escrow deposit. */
 public enum RdeResourceType {
@@ -34,11 +33,11 @@ public enum RdeResourceType {
   HEADER("urn:ietf:params:xml:ns:rdeHeader-1.0", EnumSet.of(FULL, THIN));
 
   private final String uri;
-  private final Set<RdeMode> modes;
+  private final ImmutableSet<RdeMode> modes;
 
   RdeResourceType(String uri, EnumSet<RdeMode> modes) {
     this.uri = uri;
-    this.modes = Collections.unmodifiableSet(modes);
+    this.modes = ImmutableSet.copyOf(modes);
   }
 
   /** Returns RDE XML schema URI specifying resource. */
@@ -47,7 +46,7 @@ public enum RdeResourceType {
   }
 
   /** Returns set indicating if resource is stored in BRDA thin deposits. */
-  public Set<RdeMode> getModes() {
+  public ImmutableSet<RdeMode> getModes() {
     return modes;
   }
 
diff --git a/java/google/registry/rde/RdeUploadUrl.java b/java/google/registry/rde/RdeUploadUrl.java
index 11be206ff..2cb226067 100644
--- a/java/google/registry/rde/RdeUploadUrl.java
+++ b/java/google/registry/rde/RdeUploadUrl.java
@@ -164,8 +164,7 @@ final class RdeUploadUrl implements Comparable<RdeUploadUrl> {
   @Override
   public boolean equals(@Nullable Object object) {
     return object == this
-        || object instanceof RdeUploadUrl
-        && Objects.equals(uri, ((RdeUploadUrl) object).uri);
+        || (object instanceof RdeUploadUrl && Objects.equals(uri, ((RdeUploadUrl) object).uri));
   }
 
   /** @see java.net.URI#hashCode() */
@@ -200,9 +199,9 @@ final class RdeUploadUrl implements Comparable<RdeUploadUrl> {
     @Override
     public boolean equals(@Nullable Object object) {
       return object == this
-          || object instanceof Protocol
-          && port == ((Protocol) object).port
-          && Objects.equals(name, ((Protocol) object).name);
+          || (object instanceof Protocol
+              && port == ((Protocol) object).port
+              && Objects.equals(name, ((Protocol) object).name));
     }
 
     /** @see Object#hashCode() */
diff --git a/java/google/registry/reporting/billing/CopyDetailReportsAction.java b/java/google/registry/reporting/billing/CopyDetailReportsAction.java
index 7bb6ae321..08f118d93 100644
--- a/java/google/registry/reporting/billing/CopyDetailReportsAction.java
+++ b/java/google/registry/reporting/billing/CopyDetailReportsAction.java
@@ -20,7 +20,9 @@ import static javax.servlet.http.HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
 import static javax.servlet.http.HttpServletResponse.SC_OK;
 
 import com.google.appengine.tools.cloudstorage.GcsFilename;
+import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
 import com.google.common.flogger.FluentLogger;
 import com.google.common.io.ByteStreams;
 import com.google.common.net.MediaType;
@@ -96,7 +98,7 @@ public final class CopyDetailReportsAction implements Runnable {
     for (String detailReportName : detailReportObjectNames) {
       // The standard report format is "invoice_details_yyyy-MM_registrarId_tld.csv
       // TODO(larryruili): Determine a safer way of enforcing this.
-      String registrarId = detailReportName.split("_")[3];
+      String registrarId = Iterables.get(Splitter.on('_').split(detailReportName), 3);
       Optional<Registrar> registrar = Registrar.loadByClientId(registrarId);
       if (!registrar.isPresent()) {
         logger.atWarning().log(
diff --git a/java/google/registry/tldconfig/idn/BUILD b/java/google/registry/tldconfig/idn/BUILD
index 745eb4462..e05c44e5f 100644
--- a/java/google/registry/tldconfig/idn/BUILD
+++ b/java/google/registry/tldconfig/idn/BUILD
@@ -11,6 +11,7 @@ java_library(
     deps = [
         "//java/google/registry/util",
         "//third_party/objectify:objectify-v4_1",
+        "@com_google_errorprone_error_prone_annotations",
         "@com_google_guava",
         "@com_google_re2j",
     ],
diff --git a/java/google/registry/tldconfig/idn/IdnTable.java b/java/google/registry/tldconfig/idn/IdnTable.java
index 7e8a44c92..b8587cacc 100644
--- a/java/google/registry/tldconfig/idn/IdnTable.java
+++ b/java/google/registry/tldconfig/idn/IdnTable.java
@@ -19,13 +19,14 @@ import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.collect.ImmutableRangeSet;
 import com.google.common.collect.Range;
-import com.google.common.collect.RangeSet;
+import com.google.errorprone.annotations.Immutable;
 import com.google.re2j.Matcher;
 import com.google.re2j.Pattern;
 import java.net.URI;
 import java.util.Optional;
 
 /** An IDN table for a particular TLD. */
+@Immutable
 public final class IdnTable {
 
   /** Regular expression to match a line of an IDN table. */
@@ -48,8 +49,8 @@ public final class IdnTable {
   /** Public URL of policy for this IDN table, which is needed by RDE. */
   private final URI policy;
 
-  /** {@link RangeSet} containing the valid codepoints in this table. */
-  private final RangeSet<Integer> validCodepoints;
+  /** {@link ImmutableRangeSet} containing the valid codepoints in this table. */
+  private final ImmutableRangeSet<Integer> validCodepoints;
 
   /** Validates the language rules associated with this IDN table. */
   private final Optional<LanguageValidator> languageValidator;
@@ -58,7 +59,7 @@ public final class IdnTable {
       String name,
       URI url,
       URI policy,
-      RangeSet<Integer> validCodepoints,
+      ImmutableRangeSet<Integer> validCodepoints,
       Optional<LanguageValidator> languageValidator) {
     this.name = name;
     this.url = checkNotNull(url, "%s missing '# URL: http://foo.example/page' line", name);
diff --git a/java/google/registry/tldconfig/idn/JapaneseLanguageValidator.java b/java/google/registry/tldconfig/idn/JapaneseLanguageValidator.java
index f2584bd10..55a97c433 100644
--- a/java/google/registry/tldconfig/idn/JapaneseLanguageValidator.java
+++ b/java/google/registry/tldconfig/idn/JapaneseLanguageValidator.java
@@ -22,12 +22,15 @@ import static java.lang.Character.UnicodeBlock.KATAKANA;
 import com.google.common.collect.ImmutableRangeSet;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Range;
+import com.google.errorprone.annotations.Immutable;
 import java.lang.Character.UnicodeBlock;
+import java.util.Objects;
 
 /**
  * Validates Japanese language domain labels. This class should only be used with a Japanese
  * language IDN table.
  */
+@Immutable
 class JapaneseLanguageValidator extends LanguageValidator {
 
   /** Any string with Japanese characters can have at most 15 characters. */
@@ -82,7 +85,8 @@ class JapaneseLanguageValidator extends LanguageValidator {
       // The KATAKANA_HIRAGANA_PROLONGED_SOUND_MARK can only occur after a HIRAGANA or KATAKANA
       // character.
       if (codepoint == KATAKANA_HIRAGANA_PROLONGED_SOUND_MARK
-          && precedingUnicodeBlock != HIRAGANA && precedingUnicodeBlock != KATAKANA) {
+          && !Objects.equals(precedingUnicodeBlock, HIRAGANA)
+          && !Objects.equals(precedingUnicodeBlock, KATAKANA)) {
         return false;
       }
 
diff --git a/java/google/registry/tldconfig/idn/LanguageValidator.java b/java/google/registry/tldconfig/idn/LanguageValidator.java
index f8d27462d..0b59e58ba 100644
--- a/java/google/registry/tldconfig/idn/LanguageValidator.java
+++ b/java/google/registry/tldconfig/idn/LanguageValidator.java
@@ -15,8 +15,10 @@
 package google.registry.tldconfig.idn;
 
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.Immutable;
 import java.util.Optional;
 
+@Immutable
 abstract class LanguageValidator {
 
   /** A registry of all known language validators keyed by their language code. */
diff --git a/java/google/registry/tools/CanonicalizeLabelsCommand.java b/java/google/registry/tools/CanonicalizeLabelsCommand.java
index c3bc0774b..87637df34 100644
--- a/java/google/registry/tools/CanonicalizeLabelsCommand.java
+++ b/java/google/registry/tools/CanonicalizeLabelsCommand.java
@@ -48,9 +48,10 @@ final class CanonicalizeLabelsCommand implements Command {
   @Override
   public void run() throws IOException {
     Set<String> labels = new TreeSet<>();
-    for (String label : mainParameters.isEmpty()
-        ? CharStreams.readLines(new InputStreamReader(stdin))
-        : Files.readLines(new File(mainParameters.get(0)), UTF_8)) {
+    for (String label :
+        mainParameters.isEmpty()
+            ? CharStreams.readLines(new InputStreamReader(stdin, UTF_8))
+            : Files.readLines(new File(mainParameters.get(0)), UTF_8)) {
       label = label.trim();
       if (label.startsWith("-")) {
         label = label.substring(1);
diff --git a/java/google/registry/tools/CommandUtilities.java b/java/google/registry/tools/CommandUtilities.java
index 808680401..90e474455 100644
--- a/java/google/registry/tools/CommandUtilities.java
+++ b/java/google/registry/tools/CommandUtilities.java
@@ -35,7 +35,7 @@ class CommandUtilities {
     HOST(HostResource.class),
     DOMAIN(DomainBase.class);
 
-    private Class<? extends EppResource> clazz;
+    private final Class<? extends EppResource> clazz;
 
     ResourceType(Class<? extends EppResource> clazz) {
       this.clazz = clazz;
diff --git a/java/google/registry/tools/LoggingParameters.java b/java/google/registry/tools/LoggingParameters.java
index 474dd3b17..ba6f9626b 100644
--- a/java/google/registry/tools/LoggingParameters.java
+++ b/java/google/registry/tools/LoggingParameters.java
@@ -15,6 +15,7 @@
 package google.registry.tools;
 
 import static google.registry.util.ResourceUtils.readResourceBytes;
+import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.beust.jcommander.Parameter;
 import com.beust.jcommander.Parameters;
@@ -67,7 +68,7 @@ final class LoggingParameters {
     // Add an extra leading newline in case base properties file does not end in a newline.
     String customProperties = "\n" + Joiner.on('\n').join(configLines);
     ByteSource logConfig =
-        ByteSource.concat(baseConfig, ByteSource.wrap(customProperties.getBytes()));
+        ByteSource.concat(baseConfig, ByteSource.wrap(customProperties.getBytes(UTF_8)));
     try (InputStream input = logConfig.openStream()) {
       LogManager.getLogManager().readConfiguration(input);
     }
diff --git a/java/google/registry/tools/RegistrarContactCommand.java b/java/google/registry/tools/RegistrarContactCommand.java
index 9ffcc24a8..671640871 100644
--- a/java/google/registry/tools/RegistrarContactCommand.java
+++ b/java/google/registry/tools/RegistrarContactCommand.java
@@ -32,7 +32,6 @@ import com.google.common.collect.ImmutableSet;
 import google.registry.model.common.GaeUserIdConverter;
 import google.registry.model.registrar.Registrar;
 import google.registry.model.registrar.RegistrarContact;
-import google.registry.model.registrar.RegistrarContact.Builder;
 import google.registry.tools.params.OptionalPhoneNumberParameter;
 import google.registry.tools.params.PathParameter;
 import java.io.IOException;
@@ -235,7 +234,7 @@ final class RegistrarContactCommand extends MutatingCommand {
   private RegistrarContact createContact(Registrar registrar) {
     checkArgument(!isNullOrEmpty(name), "--name is required when --mode=CREATE");
     checkArgument(!isNullOrEmpty(email), "--email is required when --mode=CREATE");
-    Builder builder = new RegistrarContact.Builder();
+    RegistrarContact.Builder builder = new RegistrarContact.Builder();
     builder.setParent(registrar);
     builder.setName(name);
     builder.setEmailAddress(email);
@@ -267,7 +266,7 @@ final class RegistrarContactCommand extends MutatingCommand {
   private RegistrarContact updateContact(RegistrarContact contact, Registrar registrar) {
     checkNotNull(registrar);
     checkNotNull(email, "--email is required when --mode=UPDATE");
-    Builder builder = contact.asBuilder();
+    RegistrarContact.Builder builder = contact.asBuilder();
     builder.setParent(registrar);
     if (!isNullOrEmpty(name)) {
       builder.setName(name);
diff --git a/java/google/registry/tools/UpdateReservedListCommand.java b/java/google/registry/tools/UpdateReservedListCommand.java
index 6d6ab0a2b..027b85d19 100644
--- a/java/google/registry/tools/UpdateReservedListCommand.java
+++ b/java/google/registry/tools/UpdateReservedListCommand.java
@@ -21,7 +21,6 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 import com.beust.jcommander.Parameters;
 import com.google.common.base.Strings;
 import google.registry.model.registry.label.ReservedList;
-import google.registry.model.registry.label.ReservedList.Builder;
 import google.registry.util.SystemClock;
 import java.nio.file.Files;
 import java.util.Optional;
@@ -36,10 +35,12 @@ final class UpdateReservedListCommand extends CreateOrUpdateReservedListCommand
     Optional<ReservedList> existing = ReservedList.get(name);
     checkArgument(
         existing.isPresent(), "Could not update reserved list %s because it doesn't exist.", name);
-    Builder updated = existing.get()
-        .asBuilder()
-        .setReservedListMapFromLines(Files.readAllLines(input, UTF_8))
-        .setLastUpdateTime(new SystemClock().nowUtc());
+    ReservedList.Builder updated =
+        existing
+            .get()
+            .asBuilder()
+            .setReservedListMapFromLines(Files.readAllLines(input, UTF_8))
+            .setLastUpdateTime(new SystemClock().nowUtc());
     if (shouldPublish != null) {
       updated.setShouldPublish(shouldPublish);
     }
diff --git a/java/google/registry/tools/ValidateEscrowDepositCommand.java b/java/google/registry/tools/ValidateEscrowDepositCommand.java
index 4e224ebc4..e589660d7 100644
--- a/java/google/registry/tools/ValidateEscrowDepositCommand.java
+++ b/java/google/registry/tools/ValidateEscrowDepositCommand.java
@@ -15,12 +15,12 @@
 package google.registry.tools;
 
 import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.collect.ImmutableList.copyOf;
 import static com.google.common.collect.Sets.difference;
 
 import com.beust.jcommander.Parameter;
 import com.beust.jcommander.Parameters;
 import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Ordering;
 import google.registry.keyring.api.Keyring;
 import google.registry.rde.Ghostryde;
@@ -40,7 +40,6 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.SortedMap;
@@ -141,17 +140,19 @@ final class ValidateEscrowDepositCommand implements Command {
     }
     System.out.println();
     boolean good = true;
-    List<String> badHostnameRefs = copyOf(difference(hostnameRefs, hostnames));
+    ImmutableList<String> badHostnameRefs =
+        ImmutableList.copyOf(difference(hostnameRefs, hostnames));
     if (!badHostnameRefs.isEmpty()) {
       System.out.printf("Bad host refs: %s\n", Joiner.on(", ").join(badHostnameRefs));
       good = false;
     }
-    List<String> badContactRefs = copyOf(difference(contactRefs, contacts));
+    ImmutableList<String> badContactRefs = ImmutableList.copyOf(difference(contactRefs, contacts));
     if (!badContactRefs.isEmpty()) {
       System.out.printf("Bad contact refs: %s\n", Joiner.on(", ").join(badContactRefs));
       good = false;
     }
-    List<String> badRegistrarRefs = copyOf(difference(registrarRefs, registrars));
+    ImmutableList<String> badRegistrarRefs =
+        ImmutableList.copyOf(difference(registrarRefs, registrars));
     if (!badRegistrarRefs.isEmpty()) {
       System.out.printf("Bad registrar refs: %s\n", Joiner.on(", ").join(badRegistrarRefs));
       good = false;
diff --git a/java/google/registry/tools/javascrap/PopulateNullRegistrarFieldsCommand.java b/java/google/registry/tools/javascrap/PopulateNullRegistrarFieldsCommand.java
index 96105db0c..2d7276952 100644
--- a/java/google/registry/tools/javascrap/PopulateNullRegistrarFieldsCommand.java
+++ b/java/google/registry/tools/javascrap/PopulateNullRegistrarFieldsCommand.java
@@ -21,7 +21,6 @@ import static google.registry.model.ofy.ObjectifyService.ofy;
 import com.beust.jcommander.Parameters;
 import com.google.common.collect.ImmutableList;
 import google.registry.model.registrar.Registrar;
-import google.registry.model.registrar.Registrar.Builder;
 import google.registry.model.registrar.RegistrarAddress;
 import google.registry.tools.MutatingCommand;
 import java.util.Objects;
@@ -40,7 +39,7 @@ public class PopulateNullRegistrarFieldsCommand extends MutatingCommand {
   @Override
   protected void init() {
     for (Registrar registrar : ofy().load().type(Registrar.class).ancestor(getCrossTldKey())) {
-      Builder changeBuilder = registrar.asBuilder();
+      Registrar.Builder changeBuilder = registrar.asBuilder();
       changeBuilder.setRegistrarName(
           firstNonNull(registrar.getRegistrarName(), registrar.getClientId()));
 
diff --git a/java/google/registry/tools/server/GenerateZoneFilesAction.java b/java/google/registry/tools/server/GenerateZoneFilesAction.java
index 8eb95f742..634c93dfb 100644
--- a/java/google/registry/tools/server/GenerateZoneFilesAction.java
+++ b/java/google/registry/tools/server/GenerateZoneFilesAction.java
@@ -101,6 +101,7 @@ public class GenerateZoneFilesAction implements Runnable, JsonActionRunner.JsonA
   @Inject @Config("gcsBufferSize") int gcsBufferSize;
   @Inject @Config("commitLogDatastoreRetention") Duration datastoreRetention;
   @Inject @Config("dnsDefaultATtl") Duration dnsDefaultATtl;
+  @SuppressWarnings("DurationVariableWithUnits") // false-positive Error Prone check
   @Inject @Config("dnsDefaultNsTtl") Duration dnsDefaultNsTtl;
   @Inject @Config("dnsDefaultDsTtl") Duration dnsDefaultDsTtl;
   @Inject Clock clock;
@@ -291,14 +292,15 @@ public class GenerateZoneFilesAction implements Runnable, JsonActionRunner.JsonA
           loadAtPointInTime(nameserver, exportTime).now().getFullyQualifiedHostName()));
     }
     for (DelegationSignerData dsData : domain.getDsData()) {
-      result.append(String.format(
-          DS_FORMAT,
-          domainLabel,
-          dnsDefaultDsTtl.getStandardSeconds(),
-          dsData.getKeyTag(),
-          dsData.getAlgorithm(),
-          dsData.getDigestType(),
-          base16().encode((dsData.getDigest()))));
+      result.append(
+          String.format(
+              DS_FORMAT,
+              domainLabel,
+              dnsDefaultDsTtl.getStandardSeconds(),
+              dsData.getKeyTag(),
+              dsData.getAlgorithm(),
+              dsData.getDigestType(),
+              base16().encode(dsData.getDigest())));
     }
     return result.toString();
   }
diff --git a/java/google/registry/ui/forms/FormFieldException.java b/java/google/registry/ui/forms/FormFieldException.java
index 0f2dec5b8..f7023aeda 100644
--- a/java/google/registry/ui/forms/FormFieldException.java
+++ b/java/google/registry/ui/forms/FormFieldException.java
@@ -156,10 +156,10 @@ public final class FormFieldException extends FormException {
   @Override
   public boolean equals(@Nullable Object obj) {
     return this == obj
-        || obj instanceof FormFieldException
-        && Objects.equals(getCause(), ((FormFieldException) obj).getCause())
-        && Objects.equals(getMessage(), ((FormFieldException) obj).getMessage())
-        && Objects.equals(names, ((FormFieldException) obj).names);
+        || (obj instanceof FormFieldException
+            && Objects.equals(getCause(), ((FormFieldException) obj).getCause())
+            && Objects.equals(getMessage(), ((FormFieldException) obj).getMessage())
+            && Objects.equals(names, ((FormFieldException) obj).names));
   }
 
   @Override
diff --git a/java/google/registry/util/CidrAddressBlock.java b/java/google/registry/util/CidrAddressBlock.java
index c7e3cda1f..de20650fd 100644
--- a/java/google/registry/util/CidrAddressBlock.java
+++ b/java/google/registry/util/CidrAddressBlock.java
@@ -450,7 +450,7 @@ public class CidrAddressBlock implements Iterable<InetAddress>, Serializable {
         }
 
         InetAddress next = InetAddresses.increment(previous);
-        return (contains(next)) ? next : null;
+        return contains(next) ? next : null;
       }
     };
   }
diff --git a/java/google/registry/util/DiffUtils.java b/java/google/registry/util/DiffUtils.java
index 596eb60c3..ddc734648 100644
--- a/java/google/registry/util/DiffUtils.java
+++ b/java/google/registry/util/DiffUtils.java
@@ -138,7 +138,7 @@ public final class DiffUtils {
           && ((DiffPair) value).b instanceof Set) {
         DiffPair pair = ((DiffPair) value);
         String prettyLineDiff = prettyPrintSetDiff((Set<?>) pair.a, (Set<?>) pair.b) + "\n";
-        output = newPath + ((prettyLineDiff.startsWith("\n")) ? ":" : ": ") + prettyLineDiff;
+        output = newPath + (prettyLineDiff.startsWith("\n") ? ":" : ": ") + prettyLineDiff;
       } else {
         output = newPath + ": " + value + "\n";
       }
diff --git a/java/google/registry/util/PosixTarHeader.java b/java/google/registry/util/PosixTarHeader.java
index cf984e996..6ec20fc9b 100644
--- a/java/google/registry/util/PosixTarHeader.java
+++ b/java/google/registry/util/PosixTarHeader.java
@@ -279,9 +279,9 @@ public final class PosixTarHeader {
   @Override
   public boolean equals(@Nullable Object rhs) {
     return rhs == this
-        || rhs != null
-        && getClass() == rhs.getClass()
-        && Arrays.equals(header, ((PosixTarHeader) rhs).header);
+        || (rhs != null
+            && getClass() == rhs.getClass()
+            && Arrays.equals(header, ((PosixTarHeader) rhs).header));
   }
 
   /** @see Arrays#toString(byte[]) */
diff --git a/java/google/registry/util/XmlEnumUtils.java b/java/google/registry/util/XmlEnumUtils.java
index ad8045773..49d0ea404 100644
--- a/java/google/registry/util/XmlEnumUtils.java
+++ b/java/google/registry/util/XmlEnumUtils.java
@@ -21,7 +21,11 @@ public class XmlEnumUtils {
   /** Read the {@link XmlEnumValue} string off of an enum. */
   public static String enumToXml(Enum<?> input) {
     try {
-      return input.getClass().getField(input.name()).getAnnotation(XmlEnumValue.class).value();
+      return input
+          .getDeclaringClass()
+          .getField(input.name())
+          .getAnnotation(XmlEnumValue.class)
+          .value();
     } catch (NoSuchFieldException e) {
       throw new RuntimeException(e);
     }
diff --git a/java/google/registry/whois/WhoisModule.java b/java/google/registry/whois/WhoisModule.java
index 2154d0329..bcbd928d1 100644
--- a/java/google/registry/whois/WhoisModule.java
+++ b/java/google/registry/whois/WhoisModule.java
@@ -41,6 +41,7 @@ import javax.servlet.http.HttpServletRequest;
 public final class WhoisModule {
 
   @Provides
+  @SuppressWarnings("CloseableProvides")
   static Reader provideHttpInputReader(HttpServletRequest req) {
     try {
       return req.getReader();
diff --git a/java/google/registry/xjc/JaxbFragment.java b/java/google/registry/xjc/JaxbFragment.java
index 494bc939f..44fef7966 100644
--- a/java/google/registry/xjc/JaxbFragment.java
+++ b/java/google/registry/xjc/JaxbFragment.java
@@ -57,13 +57,11 @@ public class JaxbFragment<T> implements Serializable {
   }
 
   /** Deserializes a JAXB element from xml bytes. */
-  private static <T> T unfreezeInstance(byte[] instanceData, Class<?> instanceType)
+  private static <T> T unfreezeInstance(byte[] instanceData, Class<T> instanceType)
       throws IOException {
     try {
       ByteArrayInputStream bin = new ByteArrayInputStream(instanceData);
-      @SuppressWarnings("unchecked")
-      T instance = (T) XjcXmlTransformer.unmarshal(instanceType, bin);
-      return instance;
+      return XjcXmlTransformer.unmarshal(instanceType, bin);
     } catch (XmlException e) {
       throw new IOException(e);
     }
@@ -91,12 +89,13 @@ public class JaxbFragment<T> implements Serializable {
     out.writeObject(freezeInstance(instance));
   }
 
+  @SuppressWarnings("unchecked")
   private void readObject(ObjectInputStream in) throws IOException {
     // read instanceType, then instanceData
-    Class<?> instanceType;
+    Class<T> instanceType;
     byte[] instanceData;
     try {
-      instanceType = (Class<?>) in.readObject();
+      instanceType = (Class<T>) in.readObject();
       instanceData = (byte[]) in.readObject();
     } catch (ClassNotFoundException e) {
       throw new RuntimeException(e);
diff --git a/java/google/registry/xjc/XjcObject.java b/java/google/registry/xjc/XjcObject.java
index 5e4e8cf1b..33a28271d 100644
--- a/java/google/registry/xjc/XjcObject.java
+++ b/java/google/registry/xjc/XjcObject.java
@@ -58,10 +58,11 @@ public abstract class XjcObject {
   public String toString() {
     try {
       StringWriter out = new StringWriter();
-      XjcXmlTransformer.marshalLenient((getClass()
-          .isAnnotationPresent(XmlRootElement.class))
+      XjcXmlTransformer.marshalLenient(
+          getClass().isAnnotationPresent(XmlRootElement.class)
               ? this
-              : new JAXBElement<>(new QName(getClass().getSimpleName()), Object.class, this), out);
+              : new JAXBElement<>(new QName(getClass().getSimpleName()), Object.class, this),
+          out);
       return out.toString();
     } catch (XmlException e) {
       return String.format("<!-- Invalid XML: %s -->", e.toString());
diff --git a/javatests/google/registry/flows/custom/TestDomainPricingCustomLogic.java b/javatests/google/registry/flows/custom/TestDomainPricingCustomLogic.java
index 386e46b25..84ce17cb9 100644
--- a/javatests/google/registry/flows/custom/TestDomainPricingCustomLogic.java
+++ b/javatests/google/registry/flows/custom/TestDomainPricingCustomLogic.java
@@ -38,7 +38,7 @@ public class TestDomainPricingCustomLogic extends DomainPricingCustomLogic {
 
   @Override
   public FeesAndCredits customizeRenewPrice(RenewPriceParameters priceParameters) {
-    return (priceParameters.domainName().toString().startsWith("costly-renew"))
+    return priceParameters.domainName().toString().startsWith("costly-renew")
         ? addCustomFee(
             priceParameters.feesAndCredits(), Fee.create(ONE_HUNDRED_BUCKS, FeeType.RENEW))
         : priceParameters.feesAndCredits();
@@ -46,7 +46,7 @@ public class TestDomainPricingCustomLogic extends DomainPricingCustomLogic {
 
   @Override
   public FeesAndCredits customizeTransferPrice(TransferPriceParameters priceParameters) {
-    return (priceParameters.domainName().toString().startsWith("expensive"))
+    return priceParameters.domainName().toString().startsWith("expensive")
         ? addCustomFee(
             priceParameters.feesAndCredits(), Fee.create(ONE_HUNDRED_BUCKS, FeeType.TRANSFER))
         : priceParameters.feesAndCredits();
@@ -54,7 +54,7 @@ public class TestDomainPricingCustomLogic extends DomainPricingCustomLogic {
 
   @Override
   public FeesAndCredits customizeUpdatePrice(UpdatePriceParameters priceParameters) {
-    return (priceParameters.domainName().toString().startsWith("non-free-update"))
+    return priceParameters.domainName().toString().startsWith("non-free-update")
         ? addCustomFee(
             priceParameters.feesAndCredits(), Fee.create(ONE_HUNDRED_BUCKS, FeeType.UPDATE))
         : priceParameters.feesAndCredits();
diff --git a/javatests/google/registry/keyring/kms/KmsKeyringTest.java b/javatests/google/registry/keyring/kms/KmsKeyringTest.java
index 9bf52aca5..4a79540ee 100644
--- a/javatests/google/registry/keyring/kms/KmsKeyringTest.java
+++ b/javatests/google/registry/keyring/kms/KmsKeyringTest.java
@@ -21,7 +21,6 @@ import com.google.common.collect.ImmutableList;
 import google.registry.keyring.api.KeySerializer;
 import google.registry.model.server.KmsSecret;
 import google.registry.model.server.KmsSecretRevision;
-import google.registry.model.server.KmsSecretRevision.Builder;
 import google.registry.testing.AppEngineRule;
 import google.registry.testing.BouncyCastleProviderRule;
 import org.bouncycastle.openpgp.PGPKeyPair;
@@ -178,7 +177,7 @@ public class KmsKeyringTest {
     KmsConnection kmsConnection = new FakeKmsConnection();
 
     KmsSecretRevision secretRevision =
-        new Builder()
+        new KmsSecretRevision.Builder()
             .setEncryptedValue(kmsConnection.encrypt(secretName, secretValue).ciphertext())
             .setKmsCryptoKeyVersionName(KmsTestHelper.DUMMY_CRYPTO_KEY_VERSION)
             .setParent(secretName)
diff --git a/javatests/google/registry/model/EntityTestCase.java b/javatests/google/registry/model/EntityTestCase.java
index cf234ff87..b822f9734 100644
--- a/javatests/google/registry/model/EntityTestCase.java
+++ b/javatests/google/registry/model/EntityTestCase.java
@@ -20,6 +20,7 @@ import static com.google.common.truth.Truth.assert_;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 import static org.joda.time.DateTimeZone.UTC;
 
+import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
 import com.googlecode.objectify.annotation.Id;
@@ -84,7 +85,7 @@ public class EntityTestCase {
     outer: for (String fieldPath : fieldPaths) {
       // Walk the field path and grab the value referred to on the object using reflection.
       Object fieldValue = obj;
-      for (String fieldName : fieldPath.split("\\.")) {
+      for (String fieldName : Splitter.on('.').split(fieldPath)) {
         if (fieldValue == null) {
           throw new RuntimeException(String.format("field '%s' not found on %s",
               fieldPath, obj.getClass().getSimpleName()));
diff --git a/javatests/google/registry/server/StaticResourceServlet.java b/javatests/google/registry/server/StaticResourceServlet.java
index 0fdff0de1..8dd0fb674 100644
--- a/javatests/google/registry/server/StaticResourceServlet.java
+++ b/javatests/google/registry/server/StaticResourceServlet.java
@@ -95,7 +95,7 @@ public final class StaticResourceServlet extends HttpServlet {
     String prefix = config.getInitParameter("prefix");
     verify(prefix.startsWith("/"));
     boolean isDirectory = Files.isDirectory(root);
-    verify(!isDirectory || isDirectory && prefix.endsWith("/"));
+    verify(!isDirectory || (isDirectory && prefix.endsWith("/")));
     fileServer = Optional.of(new FileServer(root, prefix));
   }
 
diff --git a/javatests/google/registry/testing/DatastoreHelper.java b/javatests/google/registry/testing/DatastoreHelper.java
index 1e634ec61..945656431 100644
--- a/javatests/google/registry/testing/DatastoreHelper.java
+++ b/javatests/google/registry/testing/DatastoreHelper.java
@@ -91,7 +91,6 @@ import google.registry.model.registry.label.PremiumList.PremiumListRevision;
 import google.registry.model.registry.label.ReservedList;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.model.transfer.TransferData;
-import google.registry.model.transfer.TransferData.Builder;
 import google.registry.model.transfer.TransferStatus;
 import google.registry.tmch.LordnTaskUtils;
 import java.util.Arrays;
@@ -383,7 +382,8 @@ public class DatastoreHelper {
         registrar.asBuilder().setAllowedTlds(difference(registrar.getAllowedTlds(), tld)).build());
   }
 
-  private static Builder createTransferDataBuilder(DateTime requestTime, DateTime expirationTime) {
+  private static TransferData.Builder createTransferDataBuilder(
+      DateTime requestTime, DateTime expirationTime) {
     return new TransferData.Builder()
         .setTransferStatus(TransferStatus.PENDING)
         .setGainingClientId("NewRegistrar")
@@ -585,7 +585,8 @@ public class DatastoreHelper {
     } else {
       deleteResource(autorenewPollMessage);
     }
-    Builder transferDataBuilder = createTransferDataBuilder(requestTime, expirationTime);
+    TransferData.Builder transferDataBuilder =
+        createTransferDataBuilder(requestTime, expirationTime);
     return persistResource(domain.asBuilder()
         .setPersistedCurrentSponsorClientId("TheRegistrar")
         .addStatusValue(StatusValue.PENDING_TRANSFER)
diff --git a/javatests/google/registry/testing/FakeServletInputStream.java b/javatests/google/registry/testing/FakeServletInputStream.java
index 6c694fcc8..2fb1e9df5 100644
--- a/javatests/google/registry/testing/FakeServletInputStream.java
+++ b/javatests/google/registry/testing/FakeServletInputStream.java
@@ -49,6 +49,11 @@ public final class FakeServletInputStream extends ServletInputStream {
     return input.read();
   }
 
+  @Override
+  public int read(byte[] b, int off, int len) throws IOException {
+    return input.read(b, off, len);
+  }
+
   @Override
   public void close() throws IOException {
     input.close();
diff --git a/javatests/google/registry/testing/mapreduce/MapreduceTestCase.java b/javatests/google/registry/testing/mapreduce/MapreduceTestCase.java
index 7e0452895..fc1342b41 100644
--- a/javatests/google/registry/testing/mapreduce/MapreduceTestCase.java
+++ b/javatests/google/registry/testing/mapreduce/MapreduceTestCase.java
@@ -30,6 +30,7 @@ import com.google.appengine.tools.pipeline.impl.servlets.PipelineServlet;
 import com.google.appengine.tools.pipeline.impl.servlets.TaskHandler;
 import com.google.apphosting.api.ApiProxy;
 import com.google.common.base.CharMatcher;
+import com.google.common.base.Splitter;
 import com.google.common.flogger.FluentLogger;
 import google.registry.mapreduce.MapreduceRunner;
 import google.registry.testing.AppEngineRule;
@@ -224,11 +225,11 @@ public abstract class MapreduceTestCase<T> extends ShardableTestCase {
       throws UnsupportedEncodingException {
     Map<String, String> result = new HashMap<>();
 
-    String[] params = requestBody.split("&");
+    Iterable<String> params = Splitter.on('&').split(requestBody);
     for (String param : params) {
-      String[] pair = param.split("=");
-      String name = pair[0];
-      String value = URLDecoder.decode(pair[1], "UTF-8");
+      List<String> pair = Splitter.on('=').splitToList(param);
+      String name = pair.get(0);
+      String value = URLDecoder.decode(pair.get(1), "UTF-8");
       if (result.containsKey(name)) {
         throw new IllegalArgumentException("Duplicate parameter: " + requestBody);
       }
diff --git a/javatests/google/registry/tools/CommandTestCase.java b/javatests/google/registry/tools/CommandTestCase.java
index da5a59824..53657c507 100644
--- a/javatests/google/registry/tools/CommandTestCase.java
+++ b/javatests/google/registry/tools/CommandTestCase.java
@@ -70,7 +70,7 @@ public abstract class CommandTestCase<C extends Command> {
   public TemporaryFolder tmpDir = new TemporaryFolder();
 
   @Before
-  public final void beforeCommandTestCase() {
+  public final void beforeCommandTestCase() throws Exception {
     // Ensure the UNITTEST environment has been set before constructing a new command instance.
     RegistryToolEnvironment.UNITTEST.setup(systemPropertyRule);
     command = newCommandInstance();
@@ -212,9 +212,10 @@ public abstract class CommandTestCase<C extends Command> {
   }
 
   @SuppressWarnings("unchecked")
-  protected C newCommandInstance() {
+  protected C newCommandInstance() throws Exception {
     try {
-      return (C) new TypeToken<C>(getClass()){}.getRawType().newInstance();
+      return (C)
+          new TypeToken<C>(getClass()) {}.getRawType().getDeclaredConstructor().newInstance();
     } catch (InstantiationException | IllegalAccessException e) {
       throw new RuntimeException(e);
     }
diff --git a/javatests/google/registry/whois/WhoisReaderTest.java b/javatests/google/registry/whois/WhoisReaderTest.java
index 11440c32f..22ef11ea7 100644
--- a/javatests/google/registry/whois/WhoisReaderTest.java
+++ b/javatests/google/registry/whois/WhoisReaderTest.java
@@ -298,7 +298,7 @@ public class WhoisReaderTest {
 
   @Test
   public void testNameserverLookupByIpWhitespace() throws Exception {
-    assertNsLookup(("  \t\t NAMESERVER   \t 43.34.12.213    \r\n"), "43.34.12.213");
+    assertNsLookup("  \t\t NAMESERVER   \t 43.34.12.213    \r\n", "43.34.12.213");
   }
 
   @Test
diff --git a/javatests/google/registry/xml/DateAdapterTest.java b/javatests/google/registry/xml/DateAdapterTest.java
index 580e4ecb9..55e6eed40 100644
--- a/javatests/google/registry/xml/DateAdapterTest.java
+++ b/javatests/google/registry/xml/DateAdapterTest.java
@@ -51,14 +51,14 @@ public class DateAdapterTest {
 
   @Test
   public void testUnmarshalEmpty() {
-    assertThat((new DateAdapter()).unmarshal(null)).isNull();
-    assertThat((new DateAdapter()).unmarshal("")).isNull();
+    assertThat(new DateAdapter().unmarshal(null)).isNull();
+    assertThat(new DateAdapter().unmarshal("")).isNull();
   }
 
   @Test
   public void testUnmarshalInvalid() {
     assertThrows(
         IllegalArgumentException.class,
-        () -> assertThat((new DateAdapter()).unmarshal("oh my goth")).isNull());
+        () -> assertThat(new DateAdapter().unmarshal("oh my goth")).isNull());
   }
 }
diff --git a/javatests/google/registry/xml/UtcDateTimeAdapterTest.java b/javatests/google/registry/xml/UtcDateTimeAdapterTest.java
index 02695e199..31b547076 100644
--- a/javatests/google/registry/xml/UtcDateTimeAdapterTest.java
+++ b/javatests/google/registry/xml/UtcDateTimeAdapterTest.java
@@ -43,7 +43,7 @@ public class UtcDateTimeAdapterTest {
 
   @Test
   public void testMarshalEmpty() {
-    assertThat((new UtcDateTimeAdapter()).marshal(null)).isEmpty();
+    assertThat(new UtcDateTimeAdapter().marshal(null)).isEmpty();
   }
 
   @Test
@@ -60,14 +60,14 @@ public class UtcDateTimeAdapterTest {
 
   @Test
   public void testUnmarshalEmpty() {
-    assertThat((new UtcDateTimeAdapter()).unmarshal(null)).isNull();
-    assertThat((new UtcDateTimeAdapter()).unmarshal("")).isNull();
+    assertThat(new UtcDateTimeAdapter().unmarshal(null)).isNull();
+    assertThat(new UtcDateTimeAdapter().unmarshal("")).isNull();
   }
 
   @Test
   public void testUnmarshalInvalid() {
     assertThrows(
         IllegalArgumentException.class,
-        () -> assertThat((new UtcDateTimeAdapter()).unmarshal("oh my goth")).isNull());
+        () -> assertThat(new UtcDateTimeAdapter().unmarshal("oh my goth")).isNull());
   }
 }