Remove Guava as a dependency

This commit removes Guava as a dependency. Note that Guava will remain
as a test-only dependency (transitively through Elasticsearch through
Jimfs).

Relates elastic/elasticsearchelastic/elasticsearch#13224

Original commit: elastic/x-pack-elasticsearch@fe23d5f25f

qa/pom.xml

@@ -113,11 +113,6 @@
             <artifactId>compiler</artifactId>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <scope>provided</scope>
-        </dependency>
         <dependency>
             <groupId>com.carrotsearch</groupId>
             <artifactId>hppc</artifactId>

shield/src/main/java/org/elasticsearch/shield/audit/index/IndexAuditTrail.java

@@ -5,8 +5,6 @@
  */
 package org.elasticsearch.shield.audit.index;
 
-import com.google.common.base.Splitter;
-
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.admin.cluster.state.ClusterStateResponse;
 import org.elasticsearch.action.admin.indices.exists.indices.IndicesExistsRequest;
@@ -66,11 +64,7 @@ import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.net.UnknownHostException;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.EnumSet;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.concurrent.locks.Lock;
@@ -696,7 +690,7 @@ public class IndexAuditTrail extends AbstractComponent implements AuditTrail, Cl
             List<Tuple<String, Integer>> hostPortPairs = new ArrayList<>();
 
             for (String host : hosts) {
-                List<String> hostPort = Splitter.on(":").splitToList(host.trim());
+                List<String> hostPort = Arrays.asList(host.trim().split(":"));
                 if (hostPort.size() != 1 && hostPort.size() != 2) {
                     logger.warn("invalid host:port specified: [{}] for setting [shield.audit.index.client.hosts]", host);
                 }

shield/src/test/java/org/elasticsearch/shield/authc/RunAsIntegTests.java

@@ -5,7 +5,6 @@
  */
 package org.elasticsearch.shield.authc;
 
-import com.google.common.base.Predicate;
 import org.elasticsearch.ElasticsearchSecurityException;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
 import org.elasticsearch.action.admin.cluster.node.info.NodeInfo;

watcher/src/main/java/org/elasticsearch/watcher/support/SearchRequestEquivalence.java

@@ -5,11 +5,10 @@
  */
 package org.elasticsearch.watcher.support;
 
-import com.google.common.base.Equivalence;
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.common.io.stream.BytesStreamOutput;
 
-import java.io.IOException;
+import javax.annotation.Nullable;
 import java.util.Arrays;
 
 import static org.elasticsearch.watcher.support.Exceptions.illegalState;
@@ -21,14 +20,17 @@ import static org.elasticsearch.watcher.support.Exceptions.illegalState;
  * don't compare search requests in normal runtime... we only do it in the tests. The is here basically
  * due to the lack of equals/hashcode support in SearchRequest in core.
  */
-public final class SearchRequestEquivalence extends Equivalence<SearchRequest> {
+public final class SearchRequestEquivalence {
 
     public static final SearchRequestEquivalence INSTANCE = new SearchRequestEquivalence();
 
     private SearchRequestEquivalence() {
     }
 
-    @Override
+    public final boolean equivalent(@Nullable SearchRequest a, @Nullable SearchRequest b) {
+        return a == b ? true : (a != null && b != null ? this.doEquivalent(a, b) : false);
+    }
+
     protected boolean doEquivalent(SearchRequest r1, SearchRequest r2) {
         try {
             BytesStreamOutput output1 = new BytesStreamOutput();
@@ -42,15 +44,4 @@ public final class SearchRequestEquivalence extends Equivalence<SearchRequest> {
             throw illegalState("could not compare search requests", t);
         }
     }
-
-    @Override
-    protected int doHash(SearchRequest request) {
-        try {
-            BytesStreamOutput output = new BytesStreamOutput();
-            request.writeTo(output);
-            return Arrays.hashCode(output.bytes().toBytes());
-        } catch (IOException ioe) {
-            throw illegalState("could not compute hashcode for search request", ioe);
-        }
-    }
 }

watcher/src/test/java/org/elasticsearch/watcher/WatcherLifeCycleServiceTests.java

@@ -5,7 +5,6 @@
  */
 package org.elasticsearch.watcher;
 
-import com.google.common.util.concurrent.MoreExecutors;
 import org.elasticsearch.cluster.*;
 import org.elasticsearch.cluster.block.ClusterBlocks;
 import org.elasticsearch.cluster.node.DiscoveryNodes;