Switch from Guava Optionals to Java 8 Optionals

This was a surprisingly involved change. Some of the difficulties included
java.util.Optional purposely not being Serializable (so I had to move a
few Optionals in mapreduce classes to @Nullable) and having to add the Truth
Java8 extension library for assertion support.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=171863777

java/google/registry/whois/DomainLookupCommand.java

@@ -16,9 +16,9 @@ package google.registry.whois;
 
 import static google.registry.model.EppResourceUtils.loadByForeignKey;
 
-import com.google.common.base.Optional;
 import com.google.common.net.InternetDomainName;
 import google.registry.model.domain.DomainResource;
+import java.util.Optional;
 import org.joda.time.DateTime;
 
 /** Represents a WHOIS lookup on a domain name (i.e. SLD). */
@@ -32,7 +32,7 @@ public class DomainLookupCommand extends DomainOrHostLookupCommand {
   protected Optional<WhoisResponse> getResponse(InternetDomainName domainName, DateTime now) {
     final DomainResource domainResource =
         loadByForeignKey(DomainResource.class, domainName.toString(), now);
-    return Optional.<WhoisResponse>fromNullable(
+    return Optional.<WhoisResponse>ofNullable(
         domainResource == null ? null : new DomainWhoisResponse(domainResource, now));
   }
 }

java/google/registry/whois/DomainOrHostLookupCommand.java

@@ -20,8 +20,8 @@ import static google.registry.model.registry.Registries.getTlds;
 import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Optional;
 import com.google.common.net.InternetDomainName;
+import java.util.Optional;
 import org.joda.time.DateTime;
 
 /** Represents a WHOIS lookup on a domain name (i.e. SLD) or a nameserver. */

java/google/registry/whois/DomainWhoisResponse.java

@@ -16,15 +16,12 @@ package google.registry.whois;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
-import static com.google.common.collect.Iterables.tryFind;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.util.CollectionUtils.isNullOrEmpty;
 import static google.registry.xml.UtcDateTimeAdapter.getFormattedString;
 
-import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Iterables;
 import com.googlecode.objectify.Key;
 import google.registry.model.contact.ContactPhoneNumber;
 import google.registry.model.contact.ContactResource;
@@ -39,6 +36,7 @@ import google.registry.model.registrar.RegistrarContact;
 import google.registry.model.translators.EnumToAttributeAdapter.EppEnum;
 import google.registry.util.FormattingLogger;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
 import javax.annotation.Nullable;
 import org.joda.time.DateTime;
@@ -74,8 +72,11 @@ final class DomainWhoisResponse extends WhoisResponseImpl {
         domain.getCurrentSponsorClientId());
     Registrar registrar = registrarOptional.get();
     Optional<RegistrarContact> abuseContact =
-        Iterables.tryFind(
-            registrar.getContacts(), RegistrarContact::getVisibleInDomainWhoisAsAbuse);
+        registrar
+            .getContacts()
+            .stream()
+            .filter(RegistrarContact::getVisibleInDomainWhoisAsAbuse)
+            .findFirst();
     String plaintext =
         new DomainEmitter()
             .emitField(
@@ -121,7 +122,7 @@ final class DomainWhoisResponse extends WhoisResponseImpl {
   @Nullable
   private Key<ContactResource> getContactReference(final Type type) {
     Optional<DesignatedContact> contactOfType =
-        tryFind(domain.getContacts(), d -> d.getType() == type);
+        domain.getContacts().stream().filter(d -> d.getType() == type).findFirst();
     return contactOfType.isPresent() ? contactOfType.get().getContactKey() : null;
   }
 

java/google/registry/whois/NameserverLookupByHostCommand.java

@@ -16,9 +16,9 @@ package google.registry.whois;
 
 import static google.registry.model.EppResourceUtils.loadByForeignKey;
 
-import com.google.common.base.Optional;
 import com.google.common.net.InternetDomainName;
 import google.registry.model.host.HostResource;
+import java.util.Optional;
 import org.joda.time.DateTime;
 
 /** Represents a WHOIS lookup on a nameserver based on its hostname. */
@@ -32,7 +32,7 @@ public class NameserverLookupByHostCommand extends DomainOrHostLookupCommand {
   protected Optional<WhoisResponse> getResponse(InternetDomainName hostName, DateTime now) {
     final HostResource hostResource =
         loadByForeignKey(HostResource.class, hostName.toString(), now);
-    return Optional.<WhoisResponse>fromNullable(
+    return Optional.<WhoisResponse>ofNullable(
         hostResource == null ? null : new NameserverWhoisResponse(hostResource, now));
   }
 }

java/google/registry/whois/NameserverWhoisResponse.java

@@ -18,11 +18,11 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static google.registry.model.ofy.ObjectifyService.ofy;
 
-import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.net.InetAddresses;
 import google.registry.model.host.HostResource;
 import google.registry.model.registrar.Registrar;
+import java.util.Optional;
 import org.joda.time.DateTime;
 
 /** Container for WHOIS responses to a nameserver lookup queries. */

java/google/registry/whois/WhoisMetrics.java

@@ -18,13 +18,13 @@ import static com.google.common.base.Preconditions.checkState;
 import static google.registry.monitoring.metrics.EventMetric.DEFAULT_FITTER;
 
 import com.google.auto.value.AutoValue;
-import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableSet;
 import google.registry.monitoring.metrics.EventMetric;
 import google.registry.monitoring.metrics.IncrementableMetric;
 import google.registry.monitoring.metrics.LabelDescriptor;
 import google.registry.monitoring.metrics.MetricRegistryImpl;
 import google.registry.util.Clock;
+import java.util.Optional;
 import javax.inject.Inject;
 import org.joda.time.DateTime;
 
@@ -62,12 +62,12 @@ public class WhoisMetrics {
   /** Records the given {@link WhoisMetric} and its associated processing time. */
   public void recordWhoisMetric(WhoisMetric metric) {
     whoisRequests.increment(
-        metric.commandName().or(""),
+        metric.commandName().orElse(""),
         Integer.toString(metric.numResults()),
         Integer.toString(metric.status()));
     processingTime.record(
         metric.endTimestamp().getMillis() - metric.startTimestamp().getMillis(),
-        metric.commandName().or(""),
+        metric.commandName().orElse(""),
         Integer.toString(metric.numResults()),
         Integer.toString(metric.status()));
   }

java/google/registry/whois/WhoisReader.java

@@ -21,7 +21,6 @@ import static google.registry.util.DomainNameUtils.canonicalizeDomainName;
 import static javax.servlet.http.HttpServletResponse.SC_BAD_REQUEST;
 
 import com.google.common.base.Joiner;
-import com.google.common.base.Optional;
 import com.google.common.io.CharStreams;
 import com.google.common.net.InetAddresses;
 import com.google.common.net.InternetDomainName;
@@ -31,6 +30,7 @@ import java.io.IOException;
 import java.io.Reader;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import javax.inject.Inject;
 import org.joda.time.DateTime;
 

java/google/registry/whois/WhoisResponseImpl.java

@@ -21,11 +21,11 @@ import static com.google.common.html.HtmlEscapers.htmlEscaper;
 
 import com.google.common.base.Function;
 import com.google.common.base.Joiner;
-import com.google.common.base.Optional;
 import google.registry.model.eppcommon.Address;
 import google.registry.util.Idn;
 import google.registry.xml.UtcDateTimeAdapter;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import javax.annotation.Nullable;
 import org.joda.time.DateTime;
@@ -64,9 +64,9 @@ abstract class WhoisResponseImpl implements WhoisResponse {
   static <T> T chooseByUnicodePreference(
       boolean preferUnicode, @Nullable T localized, @Nullable T internationalized) {
     if (preferUnicode) {
-      return Optional.fromNullable(localized).or(Optional.fromNullable(internationalized)).orNull();
+      return Optional.ofNullable(localized).orElse(internationalized);
     } else {
-      return Optional.fromNullable(internationalized).or(Optional.fromNullable(localized)).orNull();
+      return Optional.ofNullable(internationalized).orElse(localized);
     }
   }