diff --git a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
index 5155e6cda6..82ff5355a1 100644
--- a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
+++ b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
@@ -417,7 +417,7 @@ public abstract class AbstractDaemonTest {
 
     server.getTestInjector().injectMembers(this);
     Transport.register(inProcessProtocol);
-    toClose = Collections.synchronizedList(new ArrayList<Repository>());
+    toClose = Collections.synchronizedList(new ArrayList<>());
 
     // All groups which were added during the server start (e.g. in SchemaCreatorImpl) aren't
     // contained in the instance of the group index which is available here and in tests. There are
diff --git a/java/com/google/gerrit/gpg/PublicKeyChecker.java b/java/com/google/gerrit/gpg/PublicKeyChecker.java
index 07b42f10b5..27530e7c56 100644
--- a/java/com/google/gerrit/gpg/PublicKeyChecker.java
+++ b/java/com/google/gerrit/gpg/PublicKeyChecker.java
@@ -130,7 +130,7 @@ public class PublicKeyChecker {
     if (store == null) {
       throw new IllegalStateException("PublicKeyStore is required");
     }
-    return check(key, 0, true, trusted != null ? new HashSet<Fingerprint>() : null);
+    return check(key, 0, true, trusted != null ? new HashSet<>() : null);
   }
 
   /**
diff --git a/java/com/google/gerrit/index/query/QueryBuilder.java b/java/com/google/gerrit/index/query/QueryBuilder.java
index c6c39c3fe0..12d1dd69fe 100644
--- a/java/com/google/gerrit/index/query/QueryBuilder.java
+++ b/java/com/google/gerrit/index/query/QueryBuilder.java
@@ -101,7 +101,7 @@ public abstract class QueryBuilder<T> {
               && (method.getModifiers() & Modifier.PUBLIC) == Modifier.PUBLIC) {
             final String name = method.getName().toLowerCase();
             if (!opFactories.containsKey(name)) {
-              opFactories.put(name, new ReflectionFactory<T, Q>(name, method));
+              opFactories.put(name, new ReflectionFactory<>(name, method));
             }
           }
         }
diff --git a/java/com/google/gerrit/lucene/LuceneVersionManager.java b/java/com/google/gerrit/lucene/LuceneVersionManager.java
index d3a1a24364..f3ba73ded9 100644
--- a/java/com/google/gerrit/lucene/LuceneVersionManager.java
+++ b/java/com/google/gerrit/lucene/LuceneVersionManager.java
@@ -81,7 +81,7 @@ public class LuceneVersionManager extends VersionManager {
           continue;
         }
         if (!versions.containsKey(v)) {
-          versions.put(v, new Version<V>(null, v, true, cfg.getReady(def.getName(), v)));
+          versions.put(v, new Version<>(null, v, true, cfg.getReady(def.getName(), v)));
         }
       }
     } catch (IOException e) {
diff --git a/java/com/google/gerrit/pgm/Passwd.java b/java/com/google/gerrit/pgm/Passwd.java
index f63d2f4520..10ed07d864 100644
--- a/java/com/google/gerrit/pgm/Passwd.java
+++ b/java/com/google/gerrit/pgm/Passwd.java
@@ -78,7 +78,7 @@ public class Passwd extends SiteProgram {
             bind(Boolean.class).annotatedWith(InstallAllPlugins.class).toInstance(Boolean.FALSE);
             bind(new TypeLiteral<List<String>>() {})
                 .annotatedWith(InstallPlugins.class)
-                .toInstance(new ArrayList<String>());
+                .toInstance(new ArrayList<>());
             bind(String.class)
                 .annotatedWith(SecureStoreClassName.class)
                 .toProvider(Providers.of(getConfiguredSecureStoreClass()));
diff --git a/java/com/google/gerrit/pgm/http/jetty/JettyServer.java b/java/com/google/gerrit/pgm/http/jetty/JettyServer.java
index 25aa062c5d..7745ad4523 100644
--- a/java/com/google/gerrit/pgm/http/jetty/JettyServer.java
+++ b/java/com/google/gerrit/pgm/http/jetty/JettyServer.java
@@ -345,7 +345,7 @@ public class JettyServer {
             maxThreads,
             minThreads,
             idleTimeout,
-            new BlockingArrayQueue<Runnable>(
+            new BlockingArrayQueue<>(
                 minThreads, // capacity,
                 minThreads, // growBy,
                 maxCapacity // maxCapacity
diff --git a/java/com/google/gerrit/pgm/init/BaseInit.java b/java/com/google/gerrit/pgm/init/BaseInit.java
index 3de7947786..c1fd1dfaff 100644
--- a/java/com/google/gerrit/pgm/init/BaseInit.java
+++ b/java/com/google/gerrit/pgm/init/BaseInit.java
@@ -239,8 +239,7 @@ public class BaseInit extends SiteProgram {
           protected void configure() {
             bind(ConsoleUI.class).toInstance(ui);
             bind(Path.class).annotatedWith(SitePath.class).toInstance(sitePath);
-            List<String> plugins =
-                MoreObjects.firstNonNull(getInstallPlugins(), new ArrayList<String>());
+            List<String> plugins = MoreObjects.firstNonNull(getInstallPlugins(), new ArrayList<>());
             bind(new TypeLiteral<List<String>>() {})
                 .annotatedWith(InstallPlugins.class)
                 .toInstance(plugins);
diff --git a/java/com/google/gerrit/server/DynamicOptions.java b/java/com/google/gerrit/server/DynamicOptions.java
index dc5a262db4..dcc96d5c13 100644
--- a/java/com/google/gerrit/server/DynamicOptions.java
+++ b/java/com/google/gerrit/server/DynamicOptions.java
@@ -171,8 +171,7 @@ public class DynamicOptions {
    * classloaders.
    */
   protected static Map<ClassLoader, Map<ClassLoader, WeakReference<ClassLoader>>> mergedClByCls =
-      Collections.synchronizedMap(
-          new WeakHashMap<ClassLoader, Map<ClassLoader, WeakReference<ClassLoader>>>());
+      Collections.synchronizedMap(new WeakHashMap<>());
 
   protected Object bean;
   protected Map<String, DynamicBean> beansByPlugin;
diff --git a/java/com/google/gerrit/server/account/GroupMembers.java b/java/com/google/gerrit/server/account/GroupMembers.java
index faa162177f..375b3a1797 100644
--- a/java/com/google/gerrit/server/account/GroupMembers.java
+++ b/java/com/google/gerrit/server/account/GroupMembers.java
@@ -67,7 +67,7 @@ public class GroupMembers {
       throw new IllegalStateException("listAccounts called with PROJECT_OWNERS argument");
     }
     try {
-      return listAccounts(groupUUID, null, new HashSet<AccountGroup.UUID>());
+      return listAccounts(groupUUID, null, new HashSet<>());
     } catch (NoSuchProjectException e) {
       throw new IllegalStateException(e);
     }
@@ -81,7 +81,7 @@ public class GroupMembers {
    */
   public Set<Account> listAccounts(AccountGroup.UUID groupUUID, Project.NameKey project)
       throws NoSuchProjectException, IOException {
-    return listAccounts(groupUUID, project, new HashSet<AccountGroup.UUID>());
+    return listAccounts(groupUUID, project, new HashSet<>());
   }
 
   private Set<Account> listAccounts(
diff --git a/java/com/google/gerrit/server/config/SysExecutorModule.java b/java/com/google/gerrit/server/config/SysExecutorModule.java
index f552434395..6c729d9073 100644
--- a/java/com/google/gerrit/server/config/SysExecutorModule.java
+++ b/java/com/google/gerrit/server/config/SysExecutorModule.java
@@ -90,7 +90,7 @@ public class SysExecutorModule extends AbstractModule {
                     poolSize,
                     10,
                     TimeUnit.MINUTES,
-                    new ArrayBlockingQueue<Runnable>(poolSize),
+                    new ArrayBlockingQueue<>(poolSize),
                     new ThreadFactoryBuilder()
                         .setNameFormat("ChangeUpdate-%d")
                         .setDaemon(true)
diff --git a/java/com/google/gerrit/server/documentation/MarkdownFormatterHeader.java b/java/com/google/gerrit/server/documentation/MarkdownFormatterHeader.java
index bb8d22539a..00f7ec125d 100644
--- a/java/com/google/gerrit/server/documentation/MarkdownFormatterHeader.java
+++ b/java/com/google/gerrit/server/documentation/MarkdownFormatterHeader.java
@@ -56,7 +56,7 @@ public class MarkdownFormatterHeader {
 
     @Override
     public Set<NodeRenderingHandler<?>> getNodeRenderingHandlers() {
-      return new HashSet<NodeRenderingHandler<? extends Node>>(
+      return new HashSet<>(
           Arrays.asList(
               new NodeRenderingHandler<>(
                   AnchorLink.class,
diff --git a/java/com/google/gerrit/server/plugins/PluginMetricMaker.java b/java/com/google/gerrit/server/plugins/PluginMetricMaker.java
index 961ac10c55..b49a19061a 100644
--- a/java/com/google/gerrit/server/plugins/PluginMetricMaker.java
+++ b/java/com/google/gerrit/server/plugins/PluginMetricMaker.java
@@ -47,7 +47,7 @@ public class PluginMetricMaker extends MetricMaker implements LifecycleListener
   public PluginMetricMaker(MetricMaker root, String prefix) {
     this.root = root;
     this.prefix = prefix.endsWith("/") ? prefix : prefix + "/";
-    cleanup = Collections.synchronizedSet(new HashSet<RegistrationHandle>());
+    cleanup = Collections.synchronizedSet(new HashSet<>());
   }
 
   @Override
diff --git a/java/com/google/gerrit/server/project/ProjectConfig.java b/java/com/google/gerrit/server/project/ProjectConfig.java
index 36cffb3de6..f051d109f6 100644
--- a/java/com/google/gerrit/server/project/ProjectConfig.java
+++ b/java/com/google/gerrit/server/project/ProjectConfig.java
@@ -360,7 +360,7 @@ public class ProjectConfig extends VersionedMetaData implements ValidationError.
       String name = section.getName();
       if (sectionsWithUnknownPermissions.contains(name)) {
         AccessSection a = accessSections.get(name);
-        a.setPermissions(new ArrayList<Permission>());
+        a.setPermissions(new ArrayList<>());
       } else {
         accessSections.remove(name);
       }
diff --git a/java/com/google/gerrit/testing/FakeEmailSender.java b/java/com/google/gerrit/testing/FakeEmailSender.java
index e81d0f45b1..bbfd9b1978 100644
--- a/java/com/google/gerrit/testing/FakeEmailSender.java
+++ b/java/com/google/gerrit/testing/FakeEmailSender.java
@@ -87,7 +87,7 @@ public class FakeEmailSender implements EmailSender {
   @Inject
   FakeEmailSender(WorkQueue workQueue) {
     this.workQueue = workQueue;
-    messages = Collections.synchronizedList(new ArrayList<Message>());
+    messages = Collections.synchronizedList(new ArrayList<>());
     messagesRead = 0;
   }
 
diff --git a/javatests/com/google/gerrit/acceptance/rest/change/SubmitResolvingMergeCommitIT.java b/javatests/com/google/gerrit/acceptance/rest/change/SubmitResolvingMergeCommitIT.java
index a3b891e8f6..b4455f7dca 100644
--- a/javatests/com/google/gerrit/acceptance/rest/change/SubmitResolvingMergeCommitIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/change/SubmitResolvingMergeCommitIT.java
@@ -351,7 +351,7 @@ public class SubmitResolvingMergeCommitIT extends AbstractDaemonTest {
 
   private PushOneCommit.Result createChange(TestRepository<?> repo, String subject)
       throws Exception {
-    return createChange(repo, subject, "x", "x", new ArrayList<RevCommit>(), "refs/for/master");
+    return createChange(repo, subject, "x", "x", new ArrayList<>(), "refs/for/master");
   }
 
   private PushOneCommit.Result createChange(