Convert some Functions/Predicates to streams & lambdas

The conversion is somewhat conservative; there are many places where
we use things like Lists.transform and FluentIterable where we could
in theory switch entirely to streams, but the win is not obvious.
Converting Functions to lambdas is pretty much always a win, though.

Change-Id: I771b13bddb768426c8bb2dbf81207664994ee21d

gerrit-server/src/main/java/com/google/gerrit/metrics/Field.java

@@ -161,17 +161,10 @@ public class Field<T> {
   private static <T> Function<T, String> initFormatter(Class<T> keyType) {
     if (keyType == String.class) {
       return (Function<T, String>) Functions.<String> identity();
-
     } else if (keyType == Integer.class || keyType == Boolean.class) {
       return (Function<T, String>) Functions.toStringFunction();
-
     } else if (Enum.class.isAssignableFrom(keyType)) {
-      return new Function<T, String>() {
+      return in -> ((Enum<?>) in).name();
-        @Override
-        public String apply(T in) {
-          return ((Enum<?>) in).name();
-        }
-      };
     }
     throw new IllegalStateException("unsupported type " + keyType.getName());
   }

gerrit-server/src/main/java/com/google/gerrit/metrics/dropwizard/BucketedCallback.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.metrics.dropwizard;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Maps;
 import com.google.gerrit.metrics.Description;
@@ -124,14 +123,7 @@ abstract class BucketedCallback<V> implements BucketedMetric {
 
   @Override
   public Map<Object, Metric> getCells() {
-    return Maps.transformValues(
+    return Maps.transformValues(cells, in -> (Metric) in);
-        cells,
-        new Function<ValueGauge, Metric> () {
-          @Override
-          public Metric apply(ValueGauge in) {
-            return in;
-          }
-        });
   }
 
   final class ValueGauge implements Gauge<V> {

gerrit-server/src/main/java/com/google/gerrit/metrics/dropwizard/BucketedCounter.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.metrics.dropwizard;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Maps;
 import com.google.gerrit.metrics.Description;
@@ -98,13 +97,6 @@ abstract class BucketedCounter implements BucketedMetric {
 
   @Override
   public Map<Object, Metric> getCells() {
-    return Maps.transformValues(
+    return Maps.transformValues(cells, c -> c.metric);
-        cells,
-        new Function<CounterImpl, Metric> () {
-          @Override
-          public Metric apply(CounterImpl in) {
-            return in.metric;
-          }
-        });
   }
 }

gerrit-server/src/main/java/com/google/gerrit/metrics/dropwizard/BucketedHistogram.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.metrics.dropwizard;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Maps;
 import com.google.gerrit.metrics.Description;
@@ -96,13 +95,6 @@ abstract class BucketedHistogram implements BucketedMetric {
 
   @Override
   public Map<Object, Metric> getCells() {
-    return Maps.transformValues(
+    return Maps.transformValues(cells, h -> h.metric);
-        cells,
-        new Function<HistogramImpl, Metric> () {
-          @Override
-          public Metric apply(HistogramImpl in) {
-            return in.metric;
-          }
-        });
   }
 }

gerrit-server/src/main/java/com/google/gerrit/metrics/dropwizard/BucketedTimer.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.metrics.dropwizard;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Maps;
 import com.google.gerrit.metrics.Description;
@@ -96,13 +95,6 @@ abstract class BucketedTimer implements BucketedMetric {
 
   @Override
   public Map<Object, Metric> getCells() {
-    return Maps.transformValues(
+    return Maps.transformValues(cells, t -> t.metric);
-        cells,
-        new Function<TimerImpl, Metric> () {
-          @Override
-          public Metric apply(TimerImpl in) {
-            return in.metric;
-          }
-        });
   }
 }

gerrit-server/src/main/java/com/google/gerrit/metrics/dropwizard/DropWizardMetricMaker.java

@@ -18,7 +18,6 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.gerrit.metrics.dropwizard.MetricResource.METRIC_KIND;
 import static com.google.gerrit.server.config.ConfigResource.CONFIG_KIND;
 
-import com.google.common.base.Function;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
@@ -304,14 +303,8 @@ public class DropWizardMetricMaker extends MetricMaker {
   @Override
   public synchronized RegistrationHandle newTrigger(
       Set<CallbackMetric<?>> metrics, Runnable trigger) {
-    final ImmutableSet<CallbackMetricGlue> all = FluentIterable.from(metrics)
+    ImmutableSet<CallbackMetricGlue> all = FluentIterable.from(metrics)
-        .transform(
+        .transform(m -> (CallbackMetricGlue) m)
-          new Function<CallbackMetric<?>, CallbackMetricGlue>() {
-            @Override
-            public CallbackMetricGlue apply(CallbackMetric<?> input) {
-              return (CallbackMetricGlue) input;
-            }
-          })
         .toSet();
 
     trigger = new CallbackGroup(trigger, all);

gerrit-server/src/main/java/com/google/gerrit/server/ApprovalsUtil.java

@@ -16,9 +16,9 @@ package com.google.gerrit.server;
 
 import static com.google.gerrit.server.notedb.ReviewerStateInternal.CC;
 import static com.google.gerrit.server.notedb.ReviewerStateInternal.REVIEWER;
+import static java.util.Comparator.comparing;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Function;
 import com.google.common.base.Predicate;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableListMultimap;
@@ -52,7 +52,6 @@ import com.google.inject.Singleton;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -81,14 +80,7 @@ public class ApprovalsUtil {
       LoggerFactory.getLogger(ApprovalsUtil.class);
 
   private static final Ordering<PatchSetApproval> SORT_APPROVALS =
-      Ordering.natural()
+      Ordering.from(comparing(PatchSetApproval::getGranted));
-          .onResultOf(
-              new Function<PatchSetApproval, Timestamp>() {
-                @Override
-                public Timestamp apply(PatchSetApproval a) {
-                  return a.getGranted();
-                }
-              });
 
   public static List<PatchSetApproval> sortApprovals(
       Iterable<PatchSetApproval> approvals) {

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountResolver.java

@@ -14,8 +14,8 @@
 
 package com.google.gerrit.server.account;
 
-import com.google.common.base.Function;
+import static java.util.stream.Collectors.toSet;
-import com.google.common.collect.FluentIterable;
+
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountExternalId;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -191,14 +191,9 @@ public class AccountResolver {
 
       // At this point we have no clue. Just perform a whole bunch of suggestions
       // and pray we come up with a reasonable result list.
-      return FluentIterable
+      return accountQueryProvider.get().byDefault(nameOrEmail).stream()
-          .from(accountQueryProvider.get().byDefault(nameOrEmail))
+          .map(a -> a.getAccount().getId())
-          .transform(new Function<AccountState, Account.Id>() {
+          .collect(toSet());
-            @Override
-            public Account.Id apply(AccountState accountState) {
-              return accountState.getAccount().getId();
-            }
-          }).toSet();
     }
 
     List<Account> m = db.accounts().byFullName(nameOrEmail).toList();

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountState.java

@@ -36,12 +36,7 @@ import java.util.Set;
 
 public class AccountState {
   public static final Function<AccountState, Account.Id> ACCOUNT_ID_FUNCTION =
-      new Function<AccountState, Account.Id>() {
+      a -> a.getAccount().getId();
-        @Override
-        public Account.Id apply(AccountState in) {
-          return in.getAccount().getId();
-        }
-      };
 
   private final Account account;
   private final Set<AccountGroup.UUID> internalGroups;

gerrit-server/src/main/java/com/google/gerrit/server/account/CapabilityControl.java

@@ -14,15 +14,14 @@
 
 package com.google.gerrit.server.account;
 
-import com.google.common.base.Function;
+import static com.google.common.base.Predicates.not;
+
 import com.google.common.base.Predicate;
-import com.google.common.base.Predicates;
+import com.google.common.collect.FluentIterable;
-import com.google.common.collect.Iterables;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.common.data.PermissionRange;
 import com.google.gerrit.common.data.PermissionRule;
 import com.google.gerrit.common.data.PermissionRule.Action;
-import com.google.gerrit.reviewdb.client.AccountGroup;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.PeerDaemonUser;
 import com.google.gerrit.server.git.QueueProvider;
@@ -32,6 +31,7 @@ import com.google.inject.Inject;
 import com.google.inject.assistedinject.Assisted;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -98,7 +98,7 @@ public class CapabilityControl {
     if (canEmailReviewers == null) {
       canEmailReviewers =
           matchAny(capabilities.emailReviewers, ALLOWED_RULE)
-          || !matchAny(capabilities.emailReviewers, Predicates.not(ALLOWED_RULE));
+          || !matchAny(capabilities.emailReviewers, not(ALLOWED_RULE));
 
     }
     return canEmailReviewers;
@@ -279,23 +279,16 @@ public class CapabilityControl {
     return mine;
   }
 
-  private static final Predicate<PermissionRule> ALLOWED_RULE = new Predicate<PermissionRule>() {
+  private static final Predicate<PermissionRule> ALLOWED_RULE =
-    @Override
+      r -> r.getAction() == Action.ALLOW;
-    public boolean apply(PermissionRule rule) {
-      return rule.getAction() == Action.ALLOW;
-    }
-  };
 
-  private boolean matchAny(Iterable<PermissionRule> rules, Predicate<PermissionRule> predicate) {
+  private boolean matchAny(Collection<PermissionRule> rules,
-    Iterable<AccountGroup.UUID> ids = Iterables.transform(
+      Predicate<PermissionRule> predicate) {
-        Iterables.filter(rules, predicate),
+    return user.getEffectiveGroups()
-        new Function<PermissionRule, AccountGroup.UUID>() {
+        .containsAnyOf(
-          @Override
+            FluentIterable.from(rules)
-          public AccountGroup.UUID apply(PermissionRule rule) {
+                .filter(predicate)
-            return rule.getGroup().getUUID();
+                .transform(r -> r.getGroup().getUUID()));
-          }
-        });
-    return user.getEffectiveGroups().containsAnyOf(ids);
   }
 
   private static boolean match(GroupMembership groups,

gerrit-server/src/main/java/com/google/gerrit/server/account/DeleteWatchedProjects.java

@@ -14,8 +14,8 @@
 
 package com.google.gerrit.server.account;
 
-import com.google.common.base.Function;
+import static java.util.stream.Collectors.toList;
-import com.google.common.collect.Lists;
+
 import com.google.gerrit.extensions.client.ProjectWatchInfo;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.Response;
@@ -105,13 +105,10 @@ public class DeleteWatchedProjects
 
   private void deleteFromGit(Account.Id accountId, List<ProjectWatchInfo> input)
       throws IOException, ConfigInvalidException {
-    watchConfig.deleteProjectWatches(accountId, Lists.transform(input,
+    watchConfig.deleteProjectWatches(
-        new Function<ProjectWatchInfo, ProjectWatchKey>() {
+        accountId,
-          @Override
+        input.stream().map(w -> ProjectWatchKey.create(
-          public ProjectWatchKey apply(ProjectWatchInfo info) {
+                new Project.NameKey(w.project), w.filter))
-            return ProjectWatchKey.create(new Project.NameKey(info.project),
+            .collect(toList()));
-                info.filter);
-          }
-        }));
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/account/GetSshKeys.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.account;
 
-import com.google.common.base.Function;
 import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
 import com.google.gerrit.extensions.common.SshKeyInfo;
@@ -60,13 +59,9 @@ public class GetSshKeys implements RestReadView<AccountResource> {
 
   public List<SshKeyInfo> apply(IdentifiedUser user)
       throws RepositoryNotFoundException, IOException, ConfigInvalidException {
-    return Lists.transform(authorizedKeys.getKeys(user.getAccountId()),
+    return Lists.transform(
-        new Function<AccountSshKey, SshKeyInfo>() {
+        authorizedKeys.getKeys(user.getAccountId()),
-          @Override
+        GetSshKeys::newSshKeyInfo);
-          public SshKeyInfo apply(AccountSshKey key) {
-            return newSshKeyInfo(key);
-          }
-        });
   }
 
   public static SshKeyInfo newSshKeyInfo(AccountSshKey sshKey) {

gerrit-server/src/main/java/com/google/gerrit/server/account/InternalGroupBackend.java

@@ -14,10 +14,8 @@
 
 package com.google.gerrit.server.account;
 
-import com.google.common.base.Function;
+import static java.util.stream.Collectors.toList;
-import com.google.common.base.Predicate;
+
-import com.google.common.collect.Iterables;
-import com.google.common.collect.Lists;
 import com.google.gerrit.common.data.GroupDescription;
 import com.google.gerrit.common.data.GroupDescriptions;
 import com.google.gerrit.common.data.GroupReference;
@@ -30,18 +28,11 @@ import com.google.inject.Singleton;
 import org.eclipse.jgit.lib.ObjectId;
 
 import java.util.Collection;
+import java.util.stream.StreamSupport;
 
 /** Implementation of GroupBackend for the internal group system. */
 @Singleton
 public class InternalGroupBackend implements GroupBackend {
-  private static final Function<AccountGroup, GroupReference> ACT_GROUP_TO_GROUP_REF =
-      new Function<AccountGroup, GroupReference>() {
-        @Override
-        public GroupReference apply(AccountGroup group) {
-          return GroupReference.forGroup(group);
-        }
-      };
-
   private final GroupControl.Factory groupControlFactory;
   private final GroupCache groupCache;
   private final IncludingGroupMembership.Factory groupMembershipFactory;
@@ -77,16 +68,13 @@ public class InternalGroupBackend implements GroupBackend {
   @Override
   public Collection<GroupReference> suggest(final String name,
       final ProjectControl project) {
-    Iterable<AccountGroup> filtered = Iterables.filter(groupCache.all(),
+    return StreamSupport.stream(groupCache.all().spliterator(), false)
-        new Predicate<AccountGroup>() {
+        .filter(group ->
-          @Override
-          public boolean apply(AccountGroup group) {
             // startsWithIgnoreCase && isVisible
-            return group.getName().regionMatches(true, 0, name, 0, name.length())
+            group.getName().regionMatches(true, 0, name, 0, name.length())
-                && groupControlFactory.controlFor(group).isVisible();
+                && groupControlFactory.controlFor(group).isVisible())
-          }
+        .map(GroupReference::forGroup)
-        });
+        .collect(toList());
-    return Lists.newArrayList(Iterables.transform(filtered, ACT_GROUP_TO_GROUP_REF));
   }
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/account/VersionedAuthorizedKeys.java

@@ -15,8 +15,8 @@
 package com.google.gerrit.server.account;
 
 import static com.google.common.base.Preconditions.checkState;
+import static java.util.Comparator.comparing;
 
-import com.google.common.base.Function;
 import com.google.common.base.Optional;
 import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
@@ -278,13 +278,7 @@ public class VersionedAuthorizedKeys extends VersionedMetaData {
    * @param newKeys the new public SSH keys
    */
   public void setKeys(Collection<AccountSshKey> newKeys) {
-    Ordering<AccountSshKey> o =
+    Ordering<AccountSshKey> o = Ordering.from(comparing(k -> k.getKey().get()));
-        Ordering.natural().onResultOf(new Function<AccountSshKey, Integer>() {
-          @Override
-          public Integer apply(AccountSshKey sshKey) {
-            return sshKey.getKey().get();
-          }
-        });
     keys = new ArrayList<>(Collections.nCopies(o.max(newKeys).getKey().get(),
         Optional.<AccountSshKey> absent()));
     for (AccountSshKey key : newKeys) {

gerrit-server/src/main/java/com/google/gerrit/server/config/GetServerInfo.java

@@ -14,11 +14,11 @@
 
 package com.google.gerrit.server.config;
 
+import static java.util.stream.Collectors.toList;
+
 import com.google.common.base.CharMatcher;
-import com.google.common.base.Function;
 import com.google.common.base.Optional;
 import com.google.common.base.Strings;
-import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.gerrit.common.data.ContributorAgreement;
 import com.google.gerrit.extensions.common.AuthInfo;
@@ -225,14 +225,8 @@ public class GetServerInfo implements RestReadView<ConfigResource> {
             getDownloadSchemeInfo(scheme, downloadCommands, cloneCommands));
       }
     }
-    info.archives = Lists.newArrayList(Iterables.transform(
+    info.archives = archiveFormats.getAllowed().stream()
-        archiveFormats.getAllowed(),
+        .map(ArchiveFormat::getShortName).collect(toList());
-        new Function<ArchiveFormat, String>() {
-          @Override
-          public String apply(ArchiveFormat in) {
-            return in.getShortName();
-          }
-        }));
     return info;
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/config/ProjectConfigEntry.java

@@ -14,8 +14,8 @@
 
 package com.google.gerrit.server.config;
 
-import com.google.common.base.Function;
+import static java.util.stream.Collectors.toList;
-import com.google.common.collect.Lists;
+
 import com.google.gerrit.extensions.annotations.ExtensionPoint;
 import com.google.gerrit.extensions.api.projects.ConfigValue;
 import com.google.gerrit.extensions.api.projects.ProjectConfigEntryType;
@@ -137,14 +137,9 @@ public class ProjectConfigEntry {
       T defaultValue, Class<T> permittedValues, boolean inheritable,
       String description) {
     this(displayName, defaultValue.name(), ProjectConfigEntryType.LIST,
-        Lists.transform(
+        Arrays.stream(permittedValues.getEnumConstants())
-            Arrays.asList(permittedValues.getEnumConstants()),
+            .map(Enum::name).collect(toList()),
-            new Function<Enum<?>, String>() {
+        inheritable, description);
-              @Override
-              public String apply(Enum<?> e) {
-                return e.name();
-              }
-            }), inheritable, description);
   }
 
   public ProjectConfigEntry(String displayName, String defaultValue,

gerrit-server/src/main/java/com/google/gerrit/server/extensions/events/ReviewerAdded.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.extensions.events;
 
-import com.google.common.base.Function;
 import com.google.common.collect.Lists;
 import com.google.gerrit.extensions.api.changes.NotifyHandling;
 import com.google.gerrit.extensions.common.AccountInfo;
@@ -72,18 +71,10 @@ public class ReviewerAdded {
       return;
     }
 
-    List<AccountInfo> transformed = Lists.transform(reviewers,
-        new Function<Account.Id, AccountInfo>() {
-          @Override
-          public AccountInfo apply(Account.Id account) {
-            return util.accountInfo(account);
-          }
-        });
-
     try {
       fire(util.changeInfo(change),
           util.revisionInfo(change.getProject(), patchSet),
-          transformed,
+          Lists.transform(reviewers, util::accountInfo),
           util.accountInfo(adder),
           when);
     } catch (PatchListNotAvailableException | GpgException | IOException

gerrit-server/src/main/java/com/google/gerrit/server/extensions/webui/UiActions.java

@@ -14,11 +14,8 @@
 
 package com.google.gerrit.server.extensions.webui;
 
-import com.google.common.base.Function;
 import com.google.common.base.Predicate;
-import com.google.common.base.Predicates;
+import com.google.common.collect.FluentIterable;
-import com.google.common.collect.Iterables;
-import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.RestCollection;
@@ -33,16 +30,13 @@ import com.google.inject.Provider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Objects;
+
 public class UiActions {
   private static final Logger log = LoggerFactory.getLogger(UiActions.class);
 
   public static Predicate<UiAction.Description> enabled() {
-    return new Predicate<UiAction.Description>() {
+    return UiAction.Description::isEnabled;
-      @Override
-      public boolean apply(UiAction.Description input) {
-        return input.isEnabled();
-      }
-    };
   }
 
   public static <R extends RestResource> Iterable<UiAction.Description> from(
@@ -56,13 +50,8 @@ public class UiActions {
       DynamicMap<RestView<R>> views,
       final R resource,
       final Provider<CurrentUser> userProvider) {
-    return Iterables.filter(
+    return FluentIterable.from(views)
-      Iterables.transform(
+        .transform((DynamicMap.Entry<RestView<R>> e) -> {
-        views,
-        new Function<DynamicMap.Entry<RestView<R>>, UiAction.Description> () {
-          @Override
-          @Nullable
-          public UiAction.Description apply(DynamicMap.Entry<RestView<R>> e) {
               int d = e.getExportName().indexOf('.');
               if (d < 0) {
                 return null;
@@ -105,9 +94,8 @@ public class UiActions {
                     ? name
                     : e.getPluginName() + '~' + name);
               return dsc;
-          }
+            })
-        }),
+        .filter(Objects::nonNull);
-      Predicates.notNull());
   }
 
   private UiActions() {

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeBundle.java

@@ -345,54 +345,36 @@ public class ChangeBundle {
 
   private Map<PatchSetApproval.Key, PatchSetApproval>
       filterPatchSetApprovals() {
-    return limitToValidPatchSets(patchSetApprovals,
+    return limitToValidPatchSets(
-        new Function<PatchSetApproval.Key, PatchSet.Id>() {
+        patchSetApprovals, PatchSetApproval.Key::getParentKey);
-          @Override
-          public PatchSet.Id apply(PatchSetApproval.Key in) {
-            return in.getParentKey();
-          }
-        });
   }
 
   private Map<PatchLineComment.Key, PatchLineComment>
       filterPatchLineComments() {
-    return limitToValidPatchSets(patchLineComments,
+    return limitToValidPatchSets(
-        new Function<PatchLineComment.Key, PatchSet.Id>() {
+        patchLineComments,
-          @Override
+        k -> k.getParentKey().getParentKey());
-          public PatchSet.Id apply(PatchLineComment.Key in) {
-            return in.getParentKey().getParentKey();
-          }
-        });
   }
 
   private <K, V> Map<K, V> limitToValidPatchSets(Map<K, V> in,
-      final Function<K, PatchSet.Id> func) {
+      Function<K, PatchSet.Id> func) {
     return Maps.filterKeys(
         in, Predicates.compose(validPatchSetPredicate(), func));
   }
 
   private Predicate<PatchSet.Id> validPatchSetPredicate() {
-    final Predicate<PatchSet.Id> upToCurrent = upToCurrentPredicate();
+    Predicate<PatchSet.Id> upToCurrent = upToCurrentPredicate();
-    return new Predicate<PatchSet.Id>() {
+    return p -> upToCurrent.apply(p) && patchSets.containsKey(p);
-      @Override
-      public boolean apply(PatchSet.Id in) {
-        return upToCurrent.apply(in) && patchSets.containsKey(in);
-      }
-    };
   }
 
   private Collection<ChangeMessage> filterChangeMessages() {
     final Predicate<PatchSet.Id> validPatchSet = validPatchSetPredicate();
-    return Collections2.filter(changeMessages,
+    return Collections2.filter(changeMessages, m -> {
-        new Predicate<ChangeMessage>() {
+          PatchSet.Id psId = m.getPatchSetId();
-          @Override
-          public boolean apply(ChangeMessage in) {
-            PatchSet.Id psId = in.getPatchSetId();
           if (psId == null) {
             return true;
           }
           return validPatchSet.apply(psId);
-          }
         });
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java

@@ -19,9 +19,9 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static com.google.gerrit.reviewdb.client.RefNames.changeMetaRef;
 import static com.google.gerrit.server.notedb.NoteDbTable.CHANGES;
+import static java.util.Comparator.comparing;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Function;
 import com.google.common.base.Predicate;
 import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ImmutableList;
@@ -70,7 +70,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
-import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
@@ -84,22 +83,10 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
   private static final Logger log = LoggerFactory.getLogger(ChangeNotes.class);
 
   static final Ordering<PatchSetApproval> PSA_BY_TIME =
-      Ordering.natural().onResultOf(
+      Ordering.from(comparing(PatchSetApproval::getGranted));
-        new Function<PatchSetApproval, Timestamp>() {
-          @Override
-          public Timestamp apply(PatchSetApproval input) {
-            return input.getGranted();
-          }
-        });
 
   public static final Ordering<ChangeMessage> MESSAGE_BY_TIME =
-      Ordering.natural().onResultOf(
+      Ordering.from(comparing(ChangeMessage::getWrittenOn));
-        new Function<ChangeMessage, Timestamp>() {
-          @Override
-          public Timestamp apply(ChangeMessage input) {
-            return input.getWrittenOn();
-          }
-        });
 
   public static ConfigInvalidException parseException(Change.Id changeId,
       String fmt, Object... args) {

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotesParser.java

@@ -30,11 +30,10 @@ import static com.google.gerrit.server.notedb.ChangeNoteUtil.FOOTER_TAG;
 import static com.google.gerrit.server.notedb.ChangeNoteUtil.FOOTER_TOPIC;
 import static com.google.gerrit.server.notedb.NoteDbTable.CHANGES;
 import static java.util.Comparator.comparing;
+import static java.util.stream.Collectors.joining;
 
 import com.google.auto.value.AutoValue;
 import com.google.common.base.Enums;
-import com.google.common.base.Function;
-import com.google.common.base.Joiner;
 import com.google.common.base.Optional;
 import com.google.common.base.Splitter;
 import com.google.common.collect.ArrayListMultimap;
@@ -883,13 +882,8 @@ class ChangeNotesParser {
       missing.add(FOOTER_SUBJECT);
     }
     if (!missing.isEmpty()) {
-      throw parseException("Missing footers: " + Joiner.on(", ")
+      throw parseException("Missing footers: "
-          .join(Lists.transform(missing, new Function<FooterKey, String>() {
+          + missing.stream().map(FooterKey::getName).collect(joining(", ")));
-            @Override
-            public String apply(FooterKey input) {
-              return input.getName();
-            }
-          })));
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/notedb/RevisionNoteBuilder.java

@@ -17,10 +17,9 @@ package com.google.gerrit.server.notedb;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.gerrit.server.PatchLineCommentsUtil.PLC_ORDER;
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.stream.Collectors.toList;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ArrayListMultimap;
-import com.google.common.collect.FluentIterable;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Multimap;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
@@ -134,13 +133,10 @@ class RevisionNoteBuilder {
     }
 
     RevisionNoteData data = new RevisionNoteData();
-    data.comments = FluentIterable.from(PLC_ORDER.sortedCopy(comments.values()))
+    data.comments = comments.values().stream()
-        .transform(new Function<PatchLineComment, RevisionNoteData.Comment>() {
+        .sorted(PLC_ORDER)
-          @Override
+        .map(plc -> new RevisionNoteData.Comment(plc, noteUtil.getServerId()))
-          public RevisionNoteData.Comment apply(PatchLineComment plc) {
+        .collect(toList());
-            return new RevisionNoteData.Comment(plc, noteUtil.getServerId());
-          }
-        }).toList();
     data.pushCert = pushCert;
 
     try (OutputStreamWriter osw = new OutputStreamWriter(out)) {

gerrit-server/src/main/java/com/google/gerrit/server/notedb/RevisionNoteData.java

@@ -14,9 +14,9 @@
 
 package com.google.gerrit.server.notedb;
 
-import com.google.common.base.Function;
+import static java.util.stream.Collectors.toList;
+
 import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Lists;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Patch;
@@ -134,15 +134,15 @@ class RevisionNoteData {
   List<Comment> comments;
 
   ImmutableList<PatchLineComment> exportComments(
-      final PatchLineComment.Status status) {
+      PatchLineComment.Status status) {
     return ImmutableList.copyOf(
-        Lists.transform(comments, new Function<Comment, PatchLineComment>() {
+        comments.stream()
-          @Override
+            .map(
-          public PatchLineComment apply(Comment c) {
+                c -> {
                   PatchLineComment plc = c.export();
                   plc.setStatus(status);
                   return plc;
-          }
+                })
-        }));
+            .collect(toList()));
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchListLoader.java

@@ -16,12 +16,12 @@
 package com.google.gerrit.server.patch;
 
 import static com.google.common.base.Preconditions.checkArgument;
+
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.stream.Collectors.toSet;
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 
-import com.google.common.base.Function;
 import com.google.common.base.Throwables;
-import com.google.common.collect.FluentIterable;
 import com.google.gerrit.extensions.client.DiffPreferencesInfo.Whitespace;
 import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.Project;
@@ -70,6 +70,7 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.stream.Stream;
 
 public class PatchListLoader implements Callable<PatchList> {
   static final Logger log = LoggerFactory.getLogger(PatchListLoader.class);
@@ -179,16 +180,11 @@ public class PatchListLoader implements Callable<PatchList> {
             key.getNewId(), key.getWhitespace());
         PatchListKey oldKey = PatchListKey.againstDefaultBase(
             key.getOldId(), key.getWhitespace());
-        paths = FluentIterable
+        paths = Stream.concat(
-            .from(patchListCache.get(newKey, project).getPatches())
+                patchListCache.get(newKey, project).getPatches().stream(),
-            .append(patchListCache.get(oldKey, project).getPatches())
+                patchListCache.get(oldKey, project).getPatches().stream())
-            .transform(new Function<PatchListEntry, String>() {
+            .map(PatchListEntry::getNewName)
-              @Override
+            .collect(toSet());
-              public String apply(PatchListEntry entry) {
-                return entry.getNewName();
-              }
-            })
-            .toSet();
       }
 
       int cnt = diffEntries.size();

gerrit-server/src/main/java/com/google/gerrit/server/project/BanCommit.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.project;
 
-import com.google.common.base.Function;
 import com.google.common.collect.Lists;
 import com.google.gerrit.common.errors.PermissionDeniedException;
 import com.google.gerrit.extensions.restapi.AuthException;
@@ -91,14 +90,7 @@ public class BanCommit implements RestModifyView<ProjectResource, Input> {
     if (commits == null || commits.isEmpty()) {
       return null;
     }
-
+    return Lists.transform(commits, ObjectId::getName);
-    return Lists.transform(commits,
-        new Function<ObjectId, String>() {
-          @Override
-          public String apply(ObjectId id) {
-            return id.getName();
-          }
-        });
   }
 
   public static class BanResultInfo {

gerrit-server/src/main/java/com/google/gerrit/server/project/GetReflog.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.project;
 
-import com.google.common.base.Function;
 import com.google.common.collect.Lists;
 import com.google.gerrit.extensions.common.GitPerson;
 import com.google.gerrit.extensions.restapi.AuthException;
@@ -102,12 +101,7 @@ public class GetReflog implements RestReadView<BranchResource> {
           }
         }
       }
-      return Lists.transform(entries, new Function<ReflogEntry, ReflogEntryInfo>() {
+      return Lists.transform(entries, ReflogEntryInfo::new);
-        @Override
-        public ReflogEntryInfo apply(ReflogEntry e) {
-          return new ReflogEntryInfo(e);
-        }
-      });
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectState.java

@@ -17,7 +17,6 @@ package com.google.gerrit.server.project;
 import static com.google.gerrit.common.data.PermissionRule.Action.ALLOW;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
@@ -72,6 +71,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Function;
 
 /** Cached information on a project. */
 public class ProjectState {
@@ -378,75 +378,35 @@ public class ProjectState {
   }
 
   public boolean isUseContributorAgreements() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getUseContributorAgreements);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getUseContributorAgreements();
-      }
-    });
   }
 
   public boolean isUseContentMerge() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getUseContentMerge);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getUseContentMerge();
-      }
-    });
   }
 
   public boolean isUseSignedOffBy() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getUseSignedOffBy);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getUseSignedOffBy();
-      }
-    });
   }
 
   public boolean isRequireChangeID() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getRequireChangeID);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getRequireChangeID();
-      }
-    });
   }
 
   public boolean isCreateNewChangeForAllNotInTarget() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getCreateNewChangeForAllNotInTarget);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getCreateNewChangeForAllNotInTarget();
-      }
-    });
   }
 
   public boolean isEnableSignedPush() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getEnableSignedPush);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getEnableSignedPush();
-      }
-    });
   }
 
   public boolean isRequireSignedPush() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getRequireSignedPush);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getRequireSignedPush();
-      }
-    });
   }
 
   public boolean isRejectImplicitMerges() {
-    return getInheritableBoolean(new Function<Project, InheritableBoolean>() {
+    return getInheritableBoolean(Project::getRejectImplicitMerges);
-      @Override
-      public InheritableBoolean apply(Project input) {
-        return input.getRejectImplicitMerges();
-      }
-    });
   }
 
   public LabelTypes getLabelTypes() {
@@ -551,7 +511,8 @@ public class ProjectState {
     return Files.exists(p) ? new String(Files.readAllBytes(p), UTF_8) : null;
   }
 
-  private boolean getInheritableBoolean(Function<Project, InheritableBoolean> func) {
+  private boolean getInheritableBoolean(
+      Function<Project, InheritableBoolean> func) {
     for (ProjectState s : tree()) {
       switch (func.apply(s.getProject())) {
         case TRUE:

gerrit-server/src/main/java/com/google/gerrit/server/query/AndSource.java

@@ -16,7 +16,6 @@ package com.google.gerrit.server.query;
 
 import static com.google.common.base.Preconditions.checkArgument;
 
-import com.google.common.base.Function;
 import com.google.common.base.Throwables;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
@@ -157,12 +156,7 @@ public class AndSource<T> extends AndPredicate<T>
 
   private Iterable<T> buffer(ResultSet<T> scanner) {
     return FluentIterable.from(Iterables.partition(scanner, 50))
-        .transformAndConcat(new Function<List<T>, List<T>>() {
+        .transformAndConcat(this::transformBuffer);
-          @Override
-          public List<T> apply(List<T> buffer) {
-            return transformBuffer(buffer);
-          }
-        });
   }
 
   protected List<T> transformBuffer(List<T> buffer) throws OrmRuntimeException {

gerrit-server/src/main/java/com/google/gerrit/server/query/account/AccountQueryBuilder.java

@@ -14,7 +14,6 @@
 
 package com.google.gerrit.server.query.account;
 
-import com.google.common.base.Function;
 import com.google.common.base.Splitter;
 import com.google.common.collect.Lists;
 import com.google.common.primitives.Ints;
@@ -124,13 +123,9 @@ public class AccountQueryBuilder extends QueryBuilder<AccountState> {
 
   public Predicate<AccountState> defaultQuery(String query) {
     return Predicate.and(
-        Lists.transform(Splitter.on(' ').omitEmptyStrings().splitToList(query),
+        Lists.transform(
-            new Function<String, Predicate<AccountState>>() {
+            Splitter.on(' ').omitEmptyStrings().splitToList(query),
-              @Override
+            this::defaultField));
-              public Predicate<AccountState> apply(String s) {
-                return defaultField(s);
-              }
-            }));
   }
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

@@ -16,9 +16,9 @@ package com.google.gerrit.server.query.change;
 
 import static com.google.gerrit.reviewdb.client.Change.CHANGE_ID_PATTERN;
 import static com.google.gerrit.server.query.change.ChangeData.asChanges;
+import static java.util.stream.Collectors.toSet;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Function;
 import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
@@ -26,7 +26,6 @@ import com.google.common.collect.Lists;
 import com.google.common.primitives.Ints;
 import com.google.gerrit.common.data.GroupReference;
 import com.google.gerrit.common.errors.NotSignedInException;
-import com.google.gerrit.extensions.common.AccountInfo;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountGroup;
@@ -632,14 +631,9 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
     // expand a group predicate into multiple user predicates
     if (group != null) {
       Set<Account.Id> allMembers =
-          new HashSet<>(Lists.transform(
+          args.listMembers.get().setRecursive(true).apply(group).stream()
-              args.listMembers.get().setRecursive(true).apply(group),
+              .map(a -> new Account.Id(a._accountId))
-              new Function<AccountInfo, Account.Id>() {
+              .collect(toSet());
-                @Override
-                public Account.Id apply(AccountInfo accountInfo) {
-                  return new Account.Id(accountInfo._accountId);
-                }
-              }));
       int maxLimit = args.indexConfig.maxLimit();
       if (allMembers.size() > maxLimit) {
         // limit the number of query terms otherwise Gerrit will barf

gerrit-server/src/main/java/com/google/gerrit/server/query/change/InternalChangeQuery.java

@@ -22,7 +22,6 @@ import static com.google.gerrit.server.query.Predicate.or;
 import static com.google.gerrit.server.query.change.ChangeStatusPredicate.open;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Function;
 import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
@@ -191,20 +190,14 @@ public class InternalChangeQuery extends InternalQuery<ChangeData> {
       }
     }
 
-    return Lists.transform(notesFactory.create(db, branch.getParentKey(),
+    List<ChangeNotes> notes = notesFactory.create(
-        changeIds, new com.google.common.base.Predicate<ChangeNotes>() {
+        db, branch.getParentKey(), changeIds,
-          @Override
+        cn -> {
-          public boolean apply(ChangeNotes notes) {
+            Change c = cn.getChange();
-            Change c = notes.getChange();
             return c.getDest().equals(branch)
                 && c.getStatus() != Change.Status.MERGED;
-          }
-        }), new Function<ChangeNotes, ChangeData>() {
-          @Override
-          public ChangeData apply(ChangeNotes notes) {
-            return changeDataFactory.create(db, notes);
-          }
         });
+    return Lists.transform(notes, n -> changeDataFactory.create(db, n));
   }
 
   private Iterable<ChangeData> byCommitsOnBranchNotMergedFromIndex(

gerrit-server/src/main/java/com/google/gerrit/server/schema/ProjectConfigSchemaUpdate.java

@@ -15,9 +15,8 @@
 package com.google.gerrit.server.schema;
 
 import static com.google.gerrit.server.git.ProjectConfig.ACCESS;
+import static java.util.stream.Collectors.toList;
 
-import com.google.common.base.Function;
-import com.google.common.collect.Lists;
 import com.google.gerrit.common.data.PermissionRule;
 import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.server.git.MetaDataUpdate;
@@ -67,18 +66,16 @@ public class ProjectConfigSchemaUpdate extends VersionedMetaData {
       Set<String> names = config.getNames(ACCESS, subsection);
       if (names.contains(name)) {
         List<String> values =
-            Arrays.asList(config.getStringList(ACCESS, subsection, name));
+            Arrays.stream(config.getStringList(ACCESS, subsection, name))
-        values = Lists.transform(values, new Function<String, String>() {
+                .map(r -> {
-          @Override
+                      PermissionRule rule = PermissionRule.fromString(r, false);
-          public String apply(String ruleString) {
-            PermissionRule rule = PermissionRule.fromString(ruleString, false);
                       if (rule.getForce()) {
                         rule.setForce(false);
                         updated = true;
                       }
                       return rule.asString(false);
-          }
+                    })
-        });
+                .collect(toList());
         config.setStringList(ACCESS, subsection, name, values);
       }
     }

gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_124.java

@@ -14,7 +14,8 @@
 
 package com.google.gerrit.server.schema;
 
-import com.google.common.base.Function;
+import static java.util.Comparator.comparing;
+
 import com.google.common.base.Strings;
 import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.Multimap;
@@ -124,13 +125,7 @@ public class Schema_124 extends SchemaVersion {
 
   private Collection<AccountSshKey> fixInvalidSequenceNumbers(
       Collection<AccountSshKey> keys) {
-    Ordering<AccountSshKey> o =
+    Ordering<AccountSshKey> o = Ordering.from(comparing(k -> k.getKey().get()));
-        Ordering.natural().onResultOf(new Function<AccountSshKey, Integer>() {
-          @Override
-          public Integer apply(AccountSshKey sshKey) {
-            return sshKey.getKey().get();
-          }
-        });
     List<AccountSshKey> fixedKeys = new ArrayList<>(keys);
     AccountSshKey minKey = o.min(keys);
     while (minKey.getKey().get() <= 0) {

gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesTest.java

@@ -24,7 +24,6 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 import static org.junit.Assert.fail;
 
-import com.google.common.base.Function;
 import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableListMultimap;
@@ -34,7 +33,6 @@ import com.google.common.collect.ImmutableTable;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Lists;
-import com.google.common.collect.Ordering;
 import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.common.data.SubmitRecord;
 import com.google.gerrit.reviewdb.client.Account;
@@ -47,6 +45,7 @@ import com.google.gerrit.reviewdb.client.PatchLineComment.Status;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.PatchSetApproval;
 import com.google.gerrit.reviewdb.client.RevId;
+import com.google.gerrit.reviewdb.server.ReviewDbUtil;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.ReviewerSet;
 import com.google.gerrit.server.config.GerritServerId;
@@ -381,13 +380,9 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
     update.commit();
 
     ChangeNotes notes = newNotes(c);
-    List<PatchSetApproval> approvals = Ordering.natural().onResultOf(
+    List<PatchSetApproval> approvals = ReviewDbUtil.intKeyOrdering()
-        new Function<PatchSetApproval, Integer>() {
+        .onResultOf(PatchSetApproval::getAccountId)
-          @Override
+        .sortedCopy(notes.getApprovals().get(c.currentPatchSetId()));
-          public Integer apply(PatchSetApproval in) {
-            return in.getAccountId().get();
-          }
-        }).sortedCopy(notes.getApprovals().get(c.currentPatchSetId()));
     assertThat(approvals).hasSize(2);
 
     assertThat(approvals.get(0).getAccountId())

gerrit-server/src/test/java/com/google/gerrit/server/query/account/AbstractQueryAccountsTest.java

@@ -17,7 +17,6 @@ package com.google.gerrit.server.query.account;
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.fail;
 
-import com.google.common.base.Function;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import com.google.gerrit.extensions.api.GerritApi;
@@ -476,22 +475,10 @@ public abstract class AbstractQueryAccountsTest extends GerritServerTests {
   }
 
   protected static Iterable<Integer> ids(AccountInfo... accounts) {
-    return FluentIterable.from(Arrays.asList(accounts)).transform(
+    return FluentIterable.of(accounts).transform(a -> a._accountId);
-        new Function<AccountInfo, Integer>() {
-          @Override
-          public Integer apply(AccountInfo in) {
-            return in._accountId;
-          }
-        });
   }
 
   protected static Iterable<Integer> ids(Iterable<AccountInfo> accounts) {
-    return FluentIterable.from(accounts).transform(
+    return FluentIterable.from(accounts).transform(a -> a._accountId);
-        new Function<AccountInfo, Integer>() {
-          @Override
-          public Integer apply(AccountInfo in) {
-            return in._accountId;
-          }
-        });
   }
 }