Cleanup some of the warnings across the code base (#9445)

No logic changes, just cleans up warnings to make spotting real problems easier.

Remove "public" declarations on interfaces
Remove duplicate semicolons (Java lines ending in ";;")
Remove unneeded import
Change non-javadoc comment to not start with "/**"
Remove unneeded explicit type declarations from generics
Fix broken javadoc links

alts/src/main/java/io/grpc/alts/AltsContext.java

@@ -20,7 +20,6 @@ import io.grpc.ExperimentalApi;
 import io.grpc.alts.internal.AltsInternalContext;
 import io.grpc.alts.internal.HandshakerResult;
 import io.grpc.alts.internal.Identity;
-import io.grpc.alts.internal.SecurityLevel;
 
 /** {@code AltsContext} contains security-related information on the ALTS channel. */
 @ExperimentalApi("https://github.com/grpc/grpc-java/issues/7864")

alts/src/main/java/io/grpc/alts/internal/AltsHandshakerStub.java

@@ -64,12 +64,18 @@ class AltsHandshakerStub {
     if (!responseQueue.isEmpty()) {
       throw new IOException("Received an unexpected response.");
     }
+
     writer.onNext(req);
     Optional<HandshakerResp> result = responseQueue.take();
-    if (!result.isPresent()) {
-      maybeThrowIoException();
+    if (result.isPresent()) {
+      return result.get();
+    }
+
+    if (exceptionMessage.get() != null) {
+      throw new IOException(exceptionMessage.get());
+    } else {
+      throw new IOException("No handshaker response received");
     }
-    return result.get();
   }
 
   /** Create a new writer if the writer is null. */

alts/src/main/java/io/grpc/alts/internal/TsiHandshaker.java

@@ -86,7 +86,7 @@ public interface TsiHandshaker {
    *
    * @return the extracted peer.
    */
-  public Object extractPeerObject() throws GeneralSecurityException;
+  Object extractPeerObject() throws GeneralSecurityException;
 
   /**
    * Creates a frame protector from a completed handshake. No other methods may be called after the

api/src/main/java/io/grpc/InternalMetadata.java

@@ -19,6 +19,7 @@ package io.grpc;
 import com.google.common.io.BaseEncoding;
 import io.grpc.Metadata.AsciiMarshaller;
 import io.grpc.Metadata.BinaryStreamMarshaller;
+import java.io.InputStream;
 import java.nio.charset.Charset;
 
 /**
@@ -100,7 +101,7 @@ public final class InternalMetadata {
   /**
    * Creates a holder for a pre-parsed value read by the transport.
    *
-   * @param marshaller The {@link Metadata#BinaryStreamMarshaller} associated with this value.
+   * @param marshaller The {@link Metadata.BinaryStreamMarshaller} associated with this value.
    * @param value The value to store.
    * @return an object holding the pre-parsed value for this key.
    */

api/src/main/java/io/grpc/Metadata.java

@@ -211,8 +211,8 @@ public final class Metadata {
     return size * 2;
   }
 
+  /** checks when {@link #namesAndValues} is null or has no elements. */
   private boolean isEmpty() {
-    /** checks when {@link #namesAndValues} is null or has no elements */
     return size == 0;
   }
 

census/src/main/java/io/grpc/census/CensusStatsModule.java

@@ -188,7 +188,7 @@ final class CensusStatsModule {
     @Nullable
     private static final AtomicLongFieldUpdater<ClientTracer> inboundUncompressedSizeUpdater;
 
-    /**
+    /*
      * When using Atomic*FieldUpdater, some Samsung Android 5.0.x devices encounter a bug in their
      * JDK reflection API that triggers a NoSuchFieldException. When this occurs, we fallback to
      * (potentially racy) direct updates of the volatile variables.
@@ -268,7 +268,7 @@ final class CensusStatsModule {
     }
 
     @Override
-    @SuppressWarnings("NonAtomicVolatileUpdate")
+    @SuppressWarnings({"NonAtomicVolatileUpdate", "NonAtomicOperationOnVolatileField"})
     public void outboundWireSize(long bytes) {
       if (outboundWireSizeUpdater != null) {
         outboundWireSizeUpdater.getAndAdd(this, bytes);
@@ -562,7 +562,7 @@ final class CensusStatsModule {
     @Nullable
     private static final AtomicLongFieldUpdater<ServerTracer> inboundUncompressedSizeUpdater;
 
-    /**
+    /*
      * When using Atomic*FieldUpdater, some Samsung Android 5.0.x devices encounter a bug in their
      * JDK reflection API that triggers a NoSuchFieldException. When this occurs, we fallback to
      * (potentially racy) direct updates of the volatile variables.

census/src/main/java/io/grpc/census/CensusTracingModule.java

@@ -65,7 +65,7 @@ final class CensusTracingModule {
 
   @Nullable private static final AtomicIntegerFieldUpdater<ServerTracer> streamClosedUpdater;
 
-  /**
+  /*
    * When using Atomic*FieldUpdater, some Samsung Android 5.0.x devices encounter a bug in their JDK
    * reflection API that triggers a NoSuchFieldException. When this occurs, we fallback to
    * (potentially racy) direct updates of the volatile variables.

core/src/main/java/io/grpc/internal/BackoffPolicy.java

@@ -20,7 +20,7 @@ package io.grpc.internal;
  * Determines how long to wait before doing some action (typically a retry, or a reconnect).
  */
 public interface BackoffPolicy {
-  public interface Provider {
+  interface Provider {
     BackoffPolicy get();
   }
 

core/src/main/java/io/grpc/internal/DelayedClientCall.java

@@ -121,6 +121,7 @@ public class DelayedClientCall<ReqT, RespT> extends ClientCall<ReqT, RespT> {
     buf.append(seconds);
     buf.append(String.format(Locale.US, ".%09d", nanos));
     buf.append("s. ");
+
     /** Cancels the call if deadline exceeded prior to the real call being set. */
     class DeadlineExceededRunnable implements Runnable {
       @Override

core/src/main/java/io/grpc/internal/InternalServer.java

@@ -50,7 +50,7 @@ public interface InternalServer {
   void shutdown();
 
   /**
-   * Returns the first listening socket address.  May change after {@link start(ServerListener)} is
+   * Returns the first listening socket address.  May change after {@link #start(ServerListener)} is
    * called.
    */
   SocketAddress getListenSocketAddress();
@@ -61,7 +61,7 @@ public interface InternalServer {
   @Nullable InternalInstrumented<SocketStats> getListenSocketStats();
 
   /**
-   * Returns a list of listening socket addresses.  May change after {@link start(ServerListener)}
+   * Returns a list of listening socket addresses.  May change after {@link #start(ServerListener)}
    * is called.
    */
   List<? extends SocketAddress> getListenSocketAddresses();

core/src/main/java/io/grpc/internal/PickFirstLoadBalancerProvider.java

@@ -18,6 +18,7 @@ package io.grpc.internal;
 
 import io.grpc.LoadBalancer;
 import io.grpc.LoadBalancerProvider;
+import io.grpc.NameResolver;
 import io.grpc.NameResolver.ConfigOrError;
 import java.util.Map;
 

core/src/main/java/io/grpc/internal/StreamListener.java

@@ -59,6 +59,6 @@ public interface StreamListener {
      * messages until the producer returns null, at which point the producer may be discarded.
      */
     @Nullable
-    public InputStream next();
+    InputStream next();
   }
 }

core/src/main/java/io/grpc/util/AdvancedTlsX509KeyManager.java

@@ -246,7 +246,8 @@ public final class AdvancedTlsX509KeyManager extends X509ExtendedKeyManager {
    * Mainly used to avoid throwing IO Exceptions in java.io.Closeable.
    */
   public interface Closeable extends java.io.Closeable {
-    @Override public void close();
+    @Override
+    void close();
   }
 }
 

core/src/main/java/io/grpc/util/AdvancedTlsX509TrustManager.java

@@ -295,7 +295,8 @@ public final class AdvancedTlsX509TrustManager extends X509ExtendedTrustManager
 
   // Mainly used to avoid throwing IO Exceptions in java.io.Closeable.
   public interface Closeable extends java.io.Closeable {
-    @Override public void close();
+    @Override
+    void close();
   }
 
   public static Builder newBuilder() {

core/src/test/java/io/grpc/internal/ServiceConfigErrorHandlingTest.java

@@ -236,7 +236,7 @@ public class ServiceConfigErrorHandlingTest {
   public void emptyAddresses_validConfig_firstResolution_lbNeedsAddress() throws Exception {
     FakeNameResolverFactory nameResolverFactory =
         new FakeNameResolverFactory.Builder(expectedUri)
-            .setServers(Collections.<EquivalentAddressGroup>emptyList())
+            .setServers(Collections.emptyList())
             .build();
     channelBuilder.nameResolverFactory(nameResolverFactory);
 
@@ -299,7 +299,7 @@ public class ServiceConfigErrorHandlingTest {
   public void emptyAddresses_validConfig_lbDoesNotNeedAddress() throws Exception {
     FakeNameResolverFactory nameResolverFactory =
         new FakeNameResolverFactory.Builder(expectedUri)
-            .setServers(Collections.<EquivalentAddressGroup>emptyList())
+            .setServers(Collections.emptyList())
             .build();
     channelBuilder.nameResolverFactory(nameResolverFactory);
     when(mockLoadBalancer.canHandleEmptyAddressListFromNameResolution()).thenReturn(true);
@@ -316,7 +316,7 @@ public class ServiceConfigErrorHandlingTest {
 
     ResolvedAddresses resolvedAddresses = resultCaptor.getValue();
     assertThat(resolvedAddresses.getAddresses()).isEmpty();
-    assertThat(resolvedAddresses.getLoadBalancingPolicyConfig()).isEqualTo("val");;
+    assertThat(resolvedAddresses.getLoadBalancingPolicyConfig()).isEqualTo("val");
 
     verify(mockLoadBalancer, never()).handleNameResolutionError(any(Status.class));
     assertThat(channel.getState(false)).isNotEqualTo(ConnectivityState.TRANSIENT_FAILURE);

gcp-observability/src/test/java/io/grpc/gcp/observability/GcpObservabilityTest.java

@@ -223,7 +223,7 @@ public class GcpObservabilityTest {
       InternalLoggingChannelInterceptor.Factory channelInterceptorFactory =
           mock(InternalLoggingChannelInterceptor.Factory.class);
       InternalLoggingServerInterceptor.Factory serverInterceptorFactory =
-          mock(InternalLoggingServerInterceptor.Factory.class);;
+          mock(InternalLoggingServerInterceptor.Factory.class);
 
       try (GcpObservability unused =
           GcpObservability.grpcInit(

netty/src/main/java/io/grpc/netty/AbstractNettyHandler.java

@@ -238,7 +238,7 @@ abstract class AbstractNettyHandler extends GrpcHttp2ConnectionHandler {
 
   /** Controls whether PINGs like those for BDP are permitted to be sent at the current time. */
   public interface PingLimiter {
-    public boolean isPingAllowed();
+    boolean isPingAllowed();
   }
 
   private static final class AllowPingLimiter implements PingLimiter {

netty/src/main/java/io/grpc/netty/NettyClientTransport.java

@@ -251,7 +251,7 @@ class NettyClientTransport implements ConnectionClientTransport {
 
     ChannelHandler bufferingHandler = new WriteBufferingAndExceptionHandler(negotiationHandler);
 
-    /**
+    /*
      * We don't use a ChannelInitializer in the client bootstrap because its "initChannel" method
      * is executed in the event loop and we need this handler to be in the pipeline immediately so
      * that it may begin buffering writes.

netty/src/main/java/io/grpc/netty/WriteBufferingAndExceptionHandler.java

@@ -184,7 +184,7 @@ final class WriteBufferingAndExceptionHandler extends ChannelDuplexHandler {
    */
   @Override
   public void flush(ChannelHandlerContext ctx) {
-    /**
+    /*
      * Swallowing any flushes is not only an optimization but also required
      * for the SslHandler to work correctly. If the SslHandler receives multiple
      * flushes while the handshake is still ongoing, then the handshake "randomly"

xds/src/main/java/io/grpc/xds/XdsNameResolver.java

@@ -822,7 +822,7 @@ final class XdsNameResolver extends NameResolver {
           existingClusters == null ? clusters : Sets.difference(clusters, existingClusters);
       Set<String> deletedClusters =
           existingClusters == null
-              ? Collections.<String>emptySet() : Sets.difference(existingClusters, clusters);
+              ? Collections.emptySet() : Sets.difference(existingClusters, clusters);
       existingClusters = clusters;
       for (String cluster : addedClusters) {
         if (clusterRefs.containsKey(cluster)) {
@@ -982,7 +982,7 @@ final class XdsNameResolver extends NameResolver {
     final Map<String, FilterConfig> virtualHostOverrideConfig;
 
     private static RoutingConfig empty = new RoutingConfig(
-        0L, Collections.<Route>emptyList(), null, Collections.<String, FilterConfig>emptyMap());
+        0, Collections.emptyList(), null, Collections.emptyMap());
 
     private RoutingConfig(
         long fallbackTimeoutNano, List<Route> routes, @Nullable List<NamedFilterConfig> filterChain,

xds/src/main/java/io/grpc/xds/internal/sds/Closeable.java

@@ -19,5 +19,5 @@ package io.grpc.xds.internal.sds;
 public interface Closeable extends java.io.Closeable {
 
   @Override
-  public void close();
+  void close();
 }

xds/src/test/java/io/grpc/xds/XdsNameResolverTest.java

@@ -274,7 +274,7 @@ public class XdsNameResolverTest {
         .authorities(
             ImmutableMap.of(targetAuthority, AuthorityInfo.create(
                 "xdstp://" + targetAuthority + "/envoy.config.listener.v3.Listener/%s?foo=1&bar=2",
-                ImmutableList.<ServerInfo>of(ServerInfo.create(
+                ImmutableList.of(ServerInfo.create(
                     "td.googleapis.com", InsecureChannelCredentials.create(), true)))))
         .build();
     expectedLdsResourceName = "xdstp://xds.authority.com/envoy.config.listener.v3.Listener/"
@@ -299,12 +299,12 @@ public class XdsNameResolverTest {
   public void resolving_ldsResourceUpdateRdsName() {
     Route route1 = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
+        ImmutableMap.of());
     Route route2 = Route.forAction(RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster2, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(20L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster2, Collections.emptyList(), TimeUnit.SECONDS.toNanos(20L), null),
+        ImmutableMap.of());
 
     resolver.start(mockListener);
     FakeXdsClient xdsClient = (FakeXdsClient) resolver.getXdsClient();
@@ -313,7 +313,7 @@ public class XdsNameResolverTest {
     VirtualHost virtualHost =
         VirtualHost.create("virtualhost", Collections.singletonList(AUTHORITY),
             Collections.singletonList(route1),
-            ImmutableMap.<String, FilterConfig>of());
+            ImmutableMap.of());
     xdsClient.deliverRdsUpdate(RDS_RESOURCE_NAME, Collections.singletonList(virtualHost));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     assertServiceConfigForLoadBalancingConfig(
@@ -329,7 +329,7 @@ public class XdsNameResolverTest {
     virtualHost =
         VirtualHost.create("virtualhost-alter", Collections.singletonList(AUTHORITY),
             Collections.singletonList(route2),
-            ImmutableMap.<String, FilterConfig>of());
+            ImmutableMap.of());
     xdsClient.deliverRdsUpdate(alternativeRdsResource, Collections.singletonList(virtualHost));
     // Two new service config updates triggered:
     //  - with load balancing config being able to select cluster1 and cluster2
@@ -357,8 +357,8 @@ public class XdsNameResolverTest {
   public void resolving_ldsResourceRevokedAndAddedBack() {
     Route route = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
+        ImmutableMap.of());
 
     resolver.start(mockListener);
     FakeXdsClient xdsClient = (FakeXdsClient) resolver.getXdsClient();
@@ -367,7 +367,7 @@ public class XdsNameResolverTest {
     VirtualHost virtualHost =
         VirtualHost.create("virtualhost", Collections.singletonList(AUTHORITY),
             Collections.singletonList(route),
-            ImmutableMap.<String, FilterConfig>of());
+            ImmutableMap.of());
     xdsClient.deliverRdsUpdate(RDS_RESOURCE_NAME, Collections.singletonList(virtualHost));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     assertServiceConfigForLoadBalancingConfig(
@@ -396,8 +396,8 @@ public class XdsNameResolverTest {
   public void resolving_rdsResourceRevokedAndAddedBack() {
     Route route = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
+        ImmutableMap.of());
 
     resolver.start(mockListener);
     FakeXdsClient xdsClient = (FakeXdsClient) resolver.getXdsClient();
@@ -406,7 +406,7 @@ public class XdsNameResolverTest {
     VirtualHost virtualHost =
         VirtualHost.create("virtualhost", Collections.singletonList(AUTHORITY),
             Collections.singletonList(route),
-            ImmutableMap.<String, FilterConfig>of());
+            ImmutableMap.of());
     xdsClient.deliverRdsUpdate(RDS_RESOURCE_NAME, Collections.singletonList(virtualHost));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     assertServiceConfigForLoadBalancingConfig(
@@ -473,12 +473,12 @@ public class XdsNameResolverTest {
   public void resolving_matchingVirtualHostNotFound_matchingOverrideAuthority() {
     Route route = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
+        ImmutableMap.of());
     VirtualHost virtualHost =
         VirtualHost.create("virtualhost", Collections.singletonList("random"),
             Collections.singletonList(route),
-            ImmutableMap.<String, FilterConfig>of());
+            ImmutableMap.of());
 
     resolver = new XdsNameResolver(null, AUTHORITY, "random",
         serviceConfigParser, syncContext, scheduler,
@@ -496,12 +496,12 @@ public class XdsNameResolverTest {
   public void resolving_matchingVirtualHostNotFound_notMatchingOverrideAuthority() {
     Route route = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
+        ImmutableMap.of());
     VirtualHost virtualHost =
         VirtualHost.create("virtualhost", Collections.singletonList(AUTHORITY),
             Collections.singletonList(route),
-            ImmutableMap.<String, FilterConfig>of());
+            ImmutableMap.of());
 
     resolver = new XdsNameResolver(null, AUTHORITY, "random",
         serviceConfigParser, syncContext, scheduler,
@@ -543,19 +543,19 @@ public class XdsNameResolverTest {
   private List<VirtualHost> buildUnmatchedVirtualHosts() {
     Route route1 = Route.forAction(RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster2, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster2, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
+        ImmutableMap.of());
     Route route2 = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L), null),
+        ImmutableMap.of());
     return Arrays.asList(
         VirtualHost.create("virtualhost-foo", Collections.singletonList("hello.googleapis.com"),
             Collections.singletonList(route1),
-            ImmutableMap.<String, FilterConfig>of()),
+            ImmutableMap.of()),
         VirtualHost.create("virtualhost-bar", Collections.singletonList("hi.googleapis.com"),
             Collections.singletonList(route2),
-            ImmutableMap.<String, FilterConfig>of()));
+            ImmutableMap.of()));
   }
 
   @Test
@@ -564,11 +564,11 @@ public class XdsNameResolverTest {
     FakeXdsClient xdsClient = (FakeXdsClient) resolver.getXdsClient();
     Route route = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), null, null), // per-route timeout unset
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), null, null), // per-route timeout unset
+        ImmutableMap.of());
     VirtualHost virtualHost = VirtualHost.create("does not matter",
         Collections.singletonList(AUTHORITY), Collections.singletonList(route),
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     xdsClient.deliverLdsUpdate(0L, Collections.singletonList(virtualHost));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
@@ -582,11 +582,11 @@ public class XdsNameResolverTest {
     FakeXdsClient xdsClient = (FakeXdsClient) resolver.getXdsClient();
     Route route = Route.forAction(RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
         RouteAction.forCluster(
-            cluster1, Collections.<HashPolicy>emptyList(), null, null), // per-route timeout unset
-        ImmutableMap.<String, FilterConfig>of());
+            cluster1, Collections.emptyList(), null, null), // per-route timeout unset
+        ImmutableMap.of());
     VirtualHost virtualHost = VirtualHost.create("does not matter",
         Collections.singletonList(AUTHORITY), Collections.singletonList(route),
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     xdsClient.deliverLdsUpdate(TimeUnit.SECONDS.toNanos(5L),
         Collections.singletonList(virtualHost));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
@@ -612,10 +612,10 @@ public class XdsNameResolverTest {
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forCluster(
                     cluster1,
-                    Collections.<HashPolicy>emptyList(),
+                    Collections.emptyList(),
                     null,
                     retryPolicy),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
     InternalConfigSelector configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
@@ -668,12 +668,12 @@ public class XdsNameResolverTest {
         Arrays.asList(
             Route.forNonForwardingAction(
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
-                ImmutableMap.<String, FilterConfig>of()),
+                ImmutableMap.of()),
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
-                RouteAction.forCluster(cluster2, Collections.<HashPolicy>emptyList(),
+                RouteAction.forCluster(cluster2, Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(15L), null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
     assertThat(result.getAddresses()).isEmpty();
@@ -709,7 +709,7 @@ public class XdsNameResolverTest {
                         HashPolicy.forHeader(false, "custom-key", null, null)),
                     null,
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     InternalConfigSelector configSelector =
         resolutionResultCaptor.getValue().getAttributes().get(InternalConfigSelector.KEY);
@@ -743,7 +743,7 @@ public class XdsNameResolverTest {
                         HashPolicy.forHeader(false, "custom-key", Pattern.compile("value"), "val")),
                     null,
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     InternalConfigSelector configSelector =
         resolutionResultCaptor.getValue().getAttributes().get(InternalConfigSelector.KEY);
@@ -782,7 +782,7 @@ public class XdsNameResolverTest {
                     Collections.singletonList(HashPolicy.forChannelId(false)),
                     null,
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     InternalConfigSelector configSelector =
         resolutionResultCaptor.getValue().getAttributes().get(InternalConfigSelector.KEY);
@@ -795,7 +795,7 @@ public class XdsNameResolverTest {
 
     // Second call, with no custom header.
     startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(),
+        Collections.emptyMap(),
         CallOptions.DEFAULT);
     long hash2 = testCall.callOptions.getOption(XdsNameResolver.RPC_HASH_KEY);
 
@@ -817,14 +817,14 @@ public class XdsNameResolverTest {
                     Collections.singletonList(HashPolicy.forChannelId(false)),
                     null,
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     configSelector = resolutionResultCaptor.getValue().getAttributes().get(
         InternalConfigSelector.KEY);
 
     // Third call, with no custom header.
     startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(),
+        Collections.emptyMap(),
         CallOptions.DEFAULT);
     long hash3 = testCall.callOptions.getOption(XdsNameResolver.RPC_HASH_KEY);
 
@@ -846,15 +846,15 @@ public class XdsNameResolverTest {
             Route.forAction(
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    "another-cluster", Collections.<HashPolicy>emptyList(),
+                    "another-cluster", Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(20L), null),
-                ImmutableMap.<String, FilterConfig>of()),
+                ImmutableMap.of()),
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster2, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L),
+                    cluster2, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
     // Updated service config still contains cluster1 while it is removed resource. New calls no
@@ -886,15 +886,15 @@ public class XdsNameResolverTest {
             Route.forAction(
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    "another-cluster", Collections.<HashPolicy>emptyList(),
+                    "another-cluster", Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(20L), null),
-                ImmutableMap.<String, FilterConfig>of()),
+                ImmutableMap.of()),
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster2, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L),
+                    cluster2, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     // Two consecutive service config updates: one for removing clcuster1,
     // one for adding "another=cluster".
     verify(mockListener, times(2)).onResult(resolutionResultCaptor.capture());
@@ -922,15 +922,15 @@ public class XdsNameResolverTest {
             Route.forAction(
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    "another-cluster", Collections.<HashPolicy>emptyList(),
+                    "another-cluster", Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(20L), null),
-                ImmutableMap.<String, FilterConfig>of()),
+                ImmutableMap.of()),
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster2, Collections.<HashPolicy>emptyList(),
+                    cluster2, Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(15L), null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
 
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
@@ -943,15 +943,15 @@ public class XdsNameResolverTest {
             Route.forAction(
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    "another-cluster", Collections.<HashPolicy>emptyList(),
+                    "another-cluster", Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(15L), null),
-                ImmutableMap.<String, FilterConfig>of()),
+                ImmutableMap.of()),
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster2, Collections.<HashPolicy>emptyList(),
+                    cluster2, Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(15L), null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verifyNoMoreInteractions(mockListener);  // no cluster added/deleted
     assertCallSelectClusterResult(call1, configSelector, "another-cluster", 15.0);
   }
@@ -966,23 +966,23 @@ public class XdsNameResolverTest {
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster2, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L),
+                    cluster2, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     xdsClient.deliverLdsUpdate(
         Arrays.asList(
             Route.forAction(
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L),
+                    cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L),
                     null),
-                ImmutableMap.<String, FilterConfig>of()),
+                ImmutableMap.of()),
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster2, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L),
+                    cluster2, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     testCall.deliverErrorStatus();
     verifyNoMoreInteractions(mockListener);
   }
@@ -999,13 +999,13 @@ public class XdsNameResolverTest {
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forWeightedClusters(
                     Arrays.asList(
-                        ClusterWeight.create(cluster1, 20, ImmutableMap.<String, FilterConfig>of()),
+                        ClusterWeight.create(cluster1, 20, ImmutableMap.of()),
                         ClusterWeight.create(
-                            cluster2, 80, ImmutableMap.<String, FilterConfig>of())),
-                    Collections.<HashPolicy>emptyList(),
+                            cluster2, 80, ImmutableMap.of())),
+                    Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(20L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
     assertThat(result.getAddresses()).isEmpty();
@@ -1031,10 +1031,10 @@ public class XdsNameResolverTest {
                         "rls-plugin-foo",
                         RlsPluginConfig.create(
                             ImmutableMap.of("lookupService", "rls-cbt.googleapis.com"))),
-                    Collections.<HashPolicy>emptyList(),
+                    Collections.emptyList(),
                     TimeUnit.SECONDS.toNanos(20L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
     assertThat(result.getAddresses()).isEmpty();
@@ -1078,11 +1078,11 @@ public class XdsNameResolverTest {
                         RlsPluginConfig.create(
                             // changed
                             ImmutableMap.of("lookupService", "rls-cbt-2.googleapis.com"))),
-                    Collections.<HashPolicy>emptyList(),
+                    Collections.emptyList(),
                     // changed
                     TimeUnit.SECONDS.toNanos(30L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener, times(2)).onResult(resolutionResultCaptor.capture());
     ResolutionResult result2 = resolutionResultCaptor.getValue();
     @SuppressWarnings("unchecked")
@@ -1136,7 +1136,7 @@ public class XdsNameResolverTest {
     ClientInterceptor interceptor = result.getInterceptor();
     ClientCall<Void, Void> clientCall = interceptor.interceptCall(
         call.methodDescriptor, CallOptions.DEFAULT, channel);
-    clientCall.start(new NoopClientCallListener<Void>(), new Metadata());
+    clientCall.start(new NoopClientCallListener<>(), new Metadata());
     assertThat(testCall.callOptions.getOption(XdsNameResolver.CLUSTER_SELECTION_KEY))
         .isEqualTo("cluster:" + expectedCluster);
     @SuppressWarnings("unchecked")
@@ -1164,7 +1164,7 @@ public class XdsNameResolverTest {
     ClientInterceptor interceptor = result.getInterceptor();
     ClientCall<Void, Void> clientCall = interceptor.interceptCall(
         call.methodDescriptor, CallOptions.DEFAULT, channel);
-    clientCall.start(new NoopClientCallListener<Void>(), new Metadata());
+    clientCall.start(new NoopClientCallListener<>(), new Metadata());
     assertThat(testCall.callOptions.getOption(XdsNameResolver.CLUSTER_SELECTION_KEY))
         .isEqualTo("cluster_specifier_plugin:" + expectedPluginName);
     @SuppressWarnings("unchecked")
@@ -1186,15 +1186,15 @@ public class XdsNameResolverTest {
             Route.forAction(
                 RouteMatch.withPathExactOnly(call1.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster1, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L),
+                    cluster1, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L),
                     null),
-                ImmutableMap.<String, FilterConfig>of()),
+                ImmutableMap.of()),
             Route.forAction(
                 RouteMatch.withPathExactOnly(call2.getFullMethodNameForPath()),
                 RouteAction.forCluster(
-                    cluster2, Collections.<HashPolicy>emptyList(), TimeUnit.SECONDS.toNanos(15L),
+                    cluster2, Collections.emptyList(), TimeUnit.SECONDS.toNanos(15L),
                     null),
-                ImmutableMap.<String, FilterConfig>of())));
+                ImmutableMap.of())));
     verify(mockListener).onResult(resolutionResultCaptor.capture());
     ResolutionResult result = resolutionResultCaptor.getValue();
     assertThat(result.getAddresses()).isEmpty();
@@ -1329,7 +1329,7 @@ public class XdsNameResolverTest {
         4, ImmutableList.of(Code.UNAVAILABLE, Code.CANCELLED), Durations.fromMillis(100),
         Durations.fromMillis(200), null);
     RetryPolicy retryPolicyWithEmptyStatusCodes = RetryPolicy.create(
-        4, ImmutableList.<Code>of(), Durations.fromMillis(100), Durations.fromMillis(200), null);
+        4, ImmutableList.of(), Durations.fromMillis(100), Durations.fromMillis(200), null);
 
     // timeout only
     String expectedServiceConfigJson = "{\n"
@@ -1451,13 +1451,13 @@ public class XdsNameResolverTest {
     List<Route> routes = Collections.emptyList();
     VirtualHost vHost1 = VirtualHost.create("virtualhost01.googleapis.com",
         Arrays.asList("a.googleapis.com", "b.googleapis.com"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     VirtualHost vHost2 = VirtualHost.create("virtualhost02.googleapis.com",
         Collections.singletonList("*.googleapis.com"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     VirtualHost vHost3 = VirtualHost.create("virtualhost03.googleapis.com",
         Collections.singletonList("*"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     List<VirtualHost> virtualHosts = Arrays.asList(vHost1, vHost2, vHost3);
     assertThat(XdsNameResolver.findVirtualHostForHostName(virtualHosts, hostname))
         .isEqualTo(vHost1);
@@ -1469,13 +1469,13 @@ public class XdsNameResolverTest {
     List<Route> routes = Collections.emptyList();
     VirtualHost vHost1 = VirtualHost.create("virtualhost01.googleapis.com",
         Arrays.asList("*.googleapis.com", "b.googleapis.com"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     VirtualHost vHost2 = VirtualHost.create("virtualhost02.googleapis.com",
         Collections.singletonList("a.googleapis.*"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     VirtualHost vHost3 = VirtualHost.create("virtualhost03.googleapis.com",
         Collections.singletonList("*"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     List<VirtualHost> virtualHosts = Arrays.asList(vHost1, vHost2, vHost3);
     assertThat(XdsNameResolver.findVirtualHostForHostName(virtualHosts, hostname))
         .isEqualTo(vHost1);
@@ -1487,13 +1487,13 @@ public class XdsNameResolverTest {
     List<Route> routes = Collections.emptyList();
     VirtualHost vHost1 = VirtualHost.create("virtualhost01.googleapis.com",
         Collections.singletonList("*"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     VirtualHost vHost2 = VirtualHost.create("virtualhost02.googleapis.com",
         Collections.singletonList("b.googleapis.com"), routes,
-        ImmutableMap.<String, FilterConfig>of());
+        ImmutableMap.of());
     List<VirtualHost> virtualHosts = Arrays.asList(vHost1, vHost2);
     assertThat(XdsNameResolver.findVirtualHostForHostName(virtualHosts, hostname))
-        .isEqualTo(vHost1);;
+        .isEqualTo(vHost1);
   }
 
   @Test
@@ -1513,7 +1513,7 @@ public class XdsNameResolverTest {
     InternalConfigSelector configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     // no header abort key provided in metadata, rpc should succeed
     ClientCall.Listener<Void> observer = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcSucceeded(observer);
     // header abort http status key provided, rpc should fail
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
@@ -1582,7 +1582,7 @@ public class XdsNameResolverTest {
     result = resolutionResultCaptor.getValue();
     configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcFailed(
         observer,
         Status.UNAUTHENTICATED.withDescription(
@@ -1600,7 +1600,7 @@ public class XdsNameResolverTest {
     result = resolutionResultCaptor.getValue();
     configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcSucceeded(observer);
   }
 
@@ -1619,7 +1619,7 @@ public class XdsNameResolverTest {
     InternalConfigSelector configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     // no header delay key provided in metadata, rpc should succeed immediately
     ClientCall.Listener<Void> observer = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcSucceeded(observer);
     // header delay key provided, rpc should be delayed
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
@@ -1659,7 +1659,7 @@ public class XdsNameResolverTest {
     result = resolutionResultCaptor.getValue();
     configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcDelayed(observer, 5000L);
 
     // fixed delay, fix rate = 40%
@@ -1672,7 +1672,7 @@ public class XdsNameResolverTest {
     result = resolutionResultCaptor.getValue();
     configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcSucceeded(observer);
   }
 
@@ -1694,15 +1694,15 @@ public class XdsNameResolverTest {
     // Send two calls, then the first call should delayed and the second call should not be delayed
     // because maxActiveFaults is exceeded.
     ClientCall.Listener<Void> observer1 = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     assertThat(testCall).isNull();
     ClientCall.Listener<Void> observer2 = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcSucceeded(observer2);
     verifyRpcDelayed(observer1, 5000L);
     // Once all calls are finished, new call should be delayed.
     ClientCall.Listener<Void> observer3 = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcDelayed(observer3, 5000L);
   }
 
@@ -1728,7 +1728,7 @@ public class XdsNameResolverTest {
       }
     };
     ClientCall.Listener<Void> observer = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT.withDeadline(
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT.withDeadline(
             Deadline.after(4000, TimeUnit.NANOSECONDS, fakeTicker)));
     assertThat(testCall).isNull();
     verifyRpcDelayedThenAborted(observer, 4000L, Status.DEADLINE_EXCEEDED.withDescription(
@@ -1753,7 +1753,7 @@ public class XdsNameResolverTest {
     ResolutionResult result = resolutionResultCaptor.getValue();
     InternalConfigSelector configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     ClientCall.Listener<Void> observer = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcDelayedThenAborted(
         observer, 5000L,
         Status.UNAUTHENTICATED.withDescription(
@@ -1782,7 +1782,7 @@ public class XdsNameResolverTest {
     ResolutionResult result = resolutionResultCaptor.getValue();
     InternalConfigSelector configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     ClientCall.Listener<Void> observer = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcFailed(
         observer, Status.INTERNAL.withDescription("RPC terminated due to fault injection"));
 
@@ -1797,7 +1797,7 @@ public class XdsNameResolverTest {
     result = resolutionResultCaptor.getValue();
     configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcFailed(
         observer, Status.UNKNOWN.withDescription("RPC terminated due to fault injection"));
 
@@ -1814,7 +1814,7 @@ public class XdsNameResolverTest {
     result = resolutionResultCaptor.getValue();
     configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     observer = startNewCall(TestMethodDescriptors.voidMethod(), configSelector,
-        Collections.<String, String>emptyMap(), CallOptions.DEFAULT);
+        Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcFailed(
         observer, Status.UNAVAILABLE.withDescription("RPC terminated due to fault injection"));
   }
@@ -1843,7 +1843,7 @@ public class XdsNameResolverTest {
     ResolutionResult result = resolutionResultCaptor.getValue();
     InternalConfigSelector configSelector = result.getAttributes().get(InternalConfigSelector.KEY);
     ClientCall.Listener<Void> observer = startNewCall(TestMethodDescriptors.voidMethod(),
-        configSelector, Collections.<String, String>emptyMap(), CallOptions.DEFAULT);;
+        configSelector, Collections.emptyMap(), CallOptions.DEFAULT);
     verifyRpcFailed(
         observer, Status.UNKNOWN.withDescription("RPC terminated due to fault injection"));
   }
@@ -1904,7 +1904,7 @@ public class XdsNameResolverTest {
     RouteMatch routeMatch1 =
         RouteMatch.create(
             PathMatcher.fromPath("/FooService/barMethod", true),
-            Collections.<HeaderMatcher>emptyList(), null);
+            Collections.emptyList(), null);
     assertThat(XdsNameResolver.matchRoute(routeMatch1, "/FooService/barMethod", headers, random))
         .isTrue();
     assertThat(XdsNameResolver.matchRoute(routeMatch1, "/FooService/bazMethod", headers, random))
@@ -1913,7 +1913,7 @@ public class XdsNameResolverTest {
     RouteMatch routeMatch2 =
         RouteMatch.create(
             PathMatcher.fromPrefix("/FooService/", true),
-            Collections.<HeaderMatcher>emptyList(), null);
+            Collections.emptyList(), null);
     assertThat(XdsNameResolver.matchRoute(routeMatch2, "/FooService/barMethod", headers, random))
         .isTrue();
     assertThat(XdsNameResolver.matchRoute(routeMatch2, "/FooService/bazMethod", headers, random))
@@ -1924,7 +1924,7 @@ public class XdsNameResolverTest {
     RouteMatch routeMatch3 =
         RouteMatch.create(
             PathMatcher.fromRegEx(Pattern.compile(".*Foo.*")),
-            Collections.<HeaderMatcher>emptyList(), null);
+            Collections.emptyList(), null);
     assertThat(XdsNameResolver.matchRoute(routeMatch3, "/FooService/barMethod", headers, random))
         .isTrue();
   }
@@ -1937,14 +1937,14 @@ public class XdsNameResolverTest {
     RouteMatch routeMatch1 =
         RouteMatch.create(
             PathMatcher.fromPath("/FooService/barMethod", false),
-            Collections.<HeaderMatcher>emptyList(), null);
+            Collections.emptyList(), null);
     assertThat(XdsNameResolver.matchRoute(routeMatch1, "/fooservice/barmethod", headers, random))
         .isTrue();
 
     RouteMatch routeMatch2 =
         RouteMatch.create(
             PathMatcher.fromPrefix("/FooService", false),
-            Collections.<HeaderMatcher>emptyList(), null);
+            Collections.emptyList(), null);
     assertThat(XdsNameResolver.matchRoute(routeMatch2, "/fooservice/barmethod", headers, random))
         .isTrue();
   }
@@ -2122,7 +2122,7 @@ public class XdsNameResolverTest {
       VirtualHost virtualHost =
           VirtualHost.create(
               "virtual-host", Collections.singletonList(expectedLdsResourceName), routes,
-              ImmutableMap.<String, FilterConfig>of());
+              ImmutableMap.of());
       ldsWatcher.onChanged(LdsUpdate.forApiListener(HttpConnectionManager.forVirtualHosts(
           0L, Collections.singletonList(virtualHost), null)));
     }
@@ -2140,28 +2140,28 @@ public class XdsNameResolverTest {
           new NamedFilterConfig(FAULT_FILTER_INSTANCE_NAME, httpFilterFaultConfig),
           new NamedFilterConfig(ROUTER_FILTER_INSTANCE_NAME, RouterFilter.ROUTER_CONFIG));
       ImmutableMap<String, FilterConfig> overrideConfig = weightedClusterFaultConfig == null
-          ? ImmutableMap.<String, FilterConfig>of()
-          : ImmutableMap.<String, FilterConfig>of(
+          ? ImmutableMap.of()
+          : ImmutableMap.of(
               FAULT_FILTER_INSTANCE_NAME, weightedClusterFaultConfig);
       ClusterWeight clusterWeight =
           ClusterWeight.create(
               cluster, 100,
               overrideConfig);
       overrideConfig = routeFaultConfig == null
-          ? ImmutableMap.<String, FilterConfig>of()
-          : ImmutableMap.<String, FilterConfig>of(FAULT_FILTER_INSTANCE_NAME, routeFaultConfig);
+          ? ImmutableMap.of()
+          : ImmutableMap.of(FAULT_FILTER_INSTANCE_NAME, routeFaultConfig);
       Route route = Route.forAction(
           RouteMatch.create(
-              PathMatcher.fromPrefix("/", false), Collections.<HeaderMatcher>emptyList(), null),
+              PathMatcher.fromPrefix("/", false), Collections.emptyList(), null),
           RouteAction.forWeightedClusters(
               Collections.singletonList(clusterWeight),
-              Collections.<HashPolicy>emptyList(),
+              Collections.emptyList(),
               null,
               null),
           overrideConfig);
       overrideConfig = virtualHostFaultConfig == null
-          ? ImmutableMap.<String, FilterConfig>of()
-          : ImmutableMap.<String, FilterConfig>of(
+          ? ImmutableMap.of()
+          : ImmutableMap.of(
               FAULT_FILTER_INSTANCE_NAME, virtualHostFaultConfig);
       VirtualHost virtualHost = VirtualHost.create(
           "virtual-host",
@@ -2201,26 +2201,26 @@ public class XdsNameResolverTest {
         return;
       }
       ImmutableMap<String, FilterConfig> overrideConfig = weightedClusterFaultConfig == null
-          ? ImmutableMap.<String, FilterConfig>of()
-          : ImmutableMap.<String, FilterConfig>of(
+          ? ImmutableMap.of()
+          : ImmutableMap.of(
               FAULT_FILTER_INSTANCE_NAME, weightedClusterFaultConfig);
       ClusterWeight clusterWeight =
           ClusterWeight.create(cluster1, 100, overrideConfig);
       overrideConfig = routFaultConfig == null
-          ? ImmutableMap.<String, FilterConfig>of()
-          : ImmutableMap.<String, FilterConfig>of(FAULT_FILTER_INSTANCE_NAME, routFaultConfig);
+          ? ImmutableMap.of()
+          : ImmutableMap.of(FAULT_FILTER_INSTANCE_NAME, routFaultConfig);
       Route route = Route.forAction(
           RouteMatch.create(
-              PathMatcher.fromPrefix("/", false), Collections.<HeaderMatcher>emptyList(), null),
+              PathMatcher.fromPrefix("/", false), Collections.emptyList(), null),
           RouteAction.forWeightedClusters(
               Collections.singletonList(clusterWeight),
-              Collections.<HashPolicy>emptyList(),
+              Collections.emptyList(),
               null,
               null),
           overrideConfig);
       overrideConfig = virtualHostFaultConfig == null
-          ? ImmutableMap.<String, FilterConfig>of()
-          : ImmutableMap.<String, FilterConfig>of(
+          ? ImmutableMap.of()
+          : ImmutableMap.of(
               FAULT_FILTER_INSTANCE_NAME, virtualHostFaultConfig);
       VirtualHost virtualHost = VirtualHost.create(
           "virtual-host",