Clean up redundant code constructs

Results of the following IntelliJ inspections:
 * Redundant 'isInstance' or 'cast' call
 * Redundant array creation
 * Redundant Collection operation
 * Redundant String operation
 * Redundant type cast

The only manual change was to remove a suppression and comment about a
redundant cast which doesn't appear to be an issue in the current
version of JDK 8

Change-Id: I34a70d436512cc4efe9dafb0917be3dfce4ba06b

java/com/google/gerrit/acceptance/AbstractDaemonTest.java

@@ -725,7 +725,7 @@ public abstract class AbstractDaemonTest {
   }
 
   private static final List<Character> RANDOM =
-      Chars.asList(new char[] {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'});
+      Chars.asList('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h');
 
   protected PushOneCommit.Result amendChange(String changeId) throws Exception {
     return amendChange(changeId, "refs/for/master", admin, testRepo);

java/com/google/gerrit/asciidoctor/AsciiDoctor.java

@@ -127,7 +127,7 @@ public class AsciiDoctor {
       int equalsIndex = attribute.indexOf('=');
       if (equalsIndex > -1) {
         String name = attribute.substring(0, equalsIndex);
-        String value = attribute.substring(equalsIndex + 1, attribute.length());
+        String value = attribute.substring(equalsIndex + 1);
 
         attributeValues.put(name, value);
       } else {

java/com/google/gerrit/common/data/ParameterizedString.java

@@ -60,7 +60,7 @@ public class ParameterizedString {
         break;
       }
 
-      raw.append(pattern.substring(i, b));
+      raw.append(pattern, i, b);
       ops.add(new Constant(pattern.substring(i, b)));
 
       // "${parameter[.functions...]}" -> "parameter[.functions...]"

java/com/google/gerrit/httpd/GitOverHttpServlet.java

@@ -212,7 +212,7 @@ public class GitOverHttpServlet extends GitServlet {
     }
     // Explicit cast is required to compile under Servlet API 2.5, where the return type is raw Map.
     @SuppressWarnings("cast")
-    Map<String, String[]> parameterMap = (Map<String, String[]>) request.getParameterMap();
+    Map<String, String[]> parameterMap = request.getParameterMap();
     ImmutableListMultimap.Builder<String, String> b = ImmutableListMultimap.builder();
     parameterMap.forEach(b::putAll);
     return b.build();

java/com/google/gerrit/httpd/restapi/RestApiServlet.java

@@ -1361,9 +1361,7 @@ public class RestApiServlet extends HttpServlet {
     // generated.
     TraceContext traceContext =
         TraceContext.newTrace(
-            doTrace,
+            doTrace, traceId1, (tagName, traceId) -> res.setHeader(X_GERRIT_TRACE, traceId));
-            traceId1,
-            (tagName, traceId) -> res.setHeader(X_GERRIT_TRACE, traceId.toString()));
     // If a second trace ID was specified, add a tag for it as well.
     if (traceId2 != null) {
       traceContext.addTag(RequestId.Type.TRACE_ID, traceId2);

java/com/google/gerrit/launcher/GerritLauncher.java

@@ -324,7 +324,7 @@ public final class GerritLauncher {
     }
 
     String name = ze.getName();
-    jars.put(name.substring(name.lastIndexOf('/'), name.length()), tmp.toURI().toURL());
+    jars.put(name.substring(name.lastIndexOf('/')), tmp.toURI().toURL());
   }
 
   private static void move(SortedMap<String, URL> jars, String prefix, List<URL> extapi) {

java/com/google/gerrit/mail/MailHeaderParser.java

@@ -103,6 +103,6 @@ public class MailHeaderParser {
   }
 
   private static String extractFooter(String key, String line) {
-    return line.substring(line.indexOf(key) + key.length(), line.length()).trim();
+    return line.substring(line.indexOf(key) + key.length()).trim();
   }
 }

java/com/google/gerrit/metrics/dropwizard/BucketedCallback.java

@@ -120,7 +120,7 @@ abstract class BucketedCallback<V> implements BucketedMetric {
 
   @Override
   public Map<Object, Metric> getCells() {
-    return Maps.transformValues(cells, in -> (Metric) in);
+    return Maps.transformValues(cells, in -> in);
   }
 
   final class ValueGauge implements Gauge<V> {

java/com/google/gerrit/metrics/dropwizard/MetricJson.java

@@ -137,7 +137,7 @@ class MetricJson {
       p99_9 = s.get999thPercentile();
 
       min = (double) s.getMin();
-      avg = (double) s.getMean();
+      avg = s.getMean();
       max = (double) s.getMax();
       sum = s.getMean() * m.getCount();
       std_dev = s.getStdDev();

java/com/google/gerrit/metrics/proc/OperatingSystemMXBeanProvider.java

@@ -51,10 +51,9 @@ class OperatingSystemMXBeanProvider {
   private OperatingSystemMXBeanProvider(OperatingSystemMXBean sys)
       throws ReflectiveOperationException {
     this.sys = sys;
-    getProcessCpuTime = sys.getClass().getMethod("getProcessCpuTime", new Class<?>[] {});
+    getProcessCpuTime = sys.getClass().getMethod("getProcessCpuTime");
     getProcessCpuTime.setAccessible(true);
-    getOpenFileDescriptorCount =
+    getOpenFileDescriptorCount = sys.getClass().getMethod("getOpenFileDescriptorCount");
-        sys.getClass().getMethod("getOpenFileDescriptorCount", new Class<?>[] {});
     getOpenFileDescriptorCount.setAccessible(true);
   }
 

java/com/google/gerrit/pgm/init/InitLabels.java

@@ -61,7 +61,7 @@ public class InitLabels implements InitStep {
           KEY_LABEL,
           LABEL_VERIFIED,
           KEY_VALUE,
-          Arrays.asList(new String[] {"-1 Fails", "0 No score", "+1 Verified"}));
+          Arrays.asList("-1 Fails", "0 No score", "+1 Verified"));
       cfg.setBoolean(KEY_LABEL, LABEL_VERIFIED, KEY_COPY_ALL_SCORES_IF_NO_CODE_CHANGE, true);
       allProjectsConfig.save("Configure 'Verified' label");
     }

java/com/google/gerrit/reviewdb/client/PatchSet.java

@@ -65,7 +65,7 @@ public final class PatchSet {
     while (true) {
       int idx = joinedGroups.indexOf(',', i);
       if (idx < 0) {
-        groups.add(joinedGroups.substring(i, joinedGroups.length()));
+        groups.add(joinedGroups.substring(i));
         break;
       }
       groups.add(joinedGroups.substring(i, idx));

java/com/google/gerrit/reviewdb/client/RefNames.java

@@ -432,7 +432,7 @@ public class RefNames {
     if (i == 0) {
       return null;
     }
-    return Integer.valueOf(name.substring(i, name.length()));
+    return Integer.valueOf(name.substring(i));
   }
 
   private static StringBuilder newStringBuilder() {

java/com/google/gerrit/server/IdentifiedUser.java

@@ -96,13 +96,13 @@ public class IdentifiedUser extends CurrentUser {
           accountCache,
           groupBackend,
           disableReverseDnsLookup,
-          Providers.of((SocketAddress) null),
+          Providers.of(null),
           state,
           null);
     }
 
     public IdentifiedUser create(Account.Id id) {
-      return create((SocketAddress) null, id);
+      return create(null, id);
     }
 
     public IdentifiedUser create(SocketAddress remotePeer, Account.Id id) {

java/com/google/gerrit/server/git/MergeUtil.java

@@ -83,7 +83,6 @@ import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.errors.NoMergeBaseException;
 import org.eclipse.jgit.errors.NoMergeBaseException.MergeBaseFailureReason;
 import org.eclipse.jgit.errors.RevisionSyntaxException;
-import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
@@ -624,7 +623,7 @@ public class MergeUtil {
     }
 
     try (ObjectInserter ins = new InMemoryInserter(repo)) {
-      return newThreeWayMerger(ins, repo.getConfig()).merge(new AnyObjectId[] {mergeTip, toMerge});
+      return newThreeWayMerger(ins, repo.getConfig()).merge(mergeTip, toMerge);
     } catch (LargeObjectException e) {
       logger.atWarning().log("Cannot merge due to LargeObjectException: %s", toMerge.name());
       return false;
@@ -722,7 +721,7 @@ public class MergeUtil {
       throws IntegrationException {
     ThreeWayMerger m = newThreeWayMerger(inserter, repoConfig);
     try {
-      if (m.merge(new AnyObjectId[] {mergeTip, n})) {
+      if (m.merge(mergeTip, n)) {
         return writeMergeCommit(
             author, committer, rw, inserter, destBranch, mergeTip, m.getResultTreeId(), n);
       }

java/com/google/gerrit/server/git/WorkQueue.java

@@ -407,7 +407,7 @@ public class WorkQueue {
           new Supplier<Long>() {
             @Override
             public Long get() {
-              return (long) getTaskCount();
+              return getTaskCount();
             }
           });
       metrics.newCallbackMetric(
@@ -419,7 +419,7 @@ public class WorkQueue {
           new Supplier<Long>() {
             @Override
             public Long get() {
-              return (long) getCompletedTaskCount();
+              return getCompletedTaskCount();
             }
           });
     }
@@ -674,7 +674,7 @@ public class WorkQueue {
                 for (Field innerField : innerObj.getClass().getDeclaredFields()) {
                   if (innerField.getType().isAssignableFrom(Callable.class)) {
                     innerField.setAccessible(true);
-                    return ((Callable<?>) innerField.get(innerObj)).toString();
+                    return innerField.get(innerObj).toString();
                   }
                 }
               }

java/com/google/gerrit/server/index/change/ChangeField.java

@@ -297,7 +297,7 @@ public class ChangeField {
         continue;
       }
 
-      Long l = Longs.tryParse(v.substring(i2 + 1, v.length()));
+      Long l = Longs.tryParse(v.substring(i2 + 1));
       if (l == null) {
         logger.atWarning().log(
             "Failed to parse timestamp of reviewer field from change %s: %s", changeId.get(), v);
@@ -350,7 +350,7 @@ public class ChangeField {
         continue;
       }
 
-      Long l = Longs.tryParse(v.substring(i2 + 1, v.length()));
+      Long l = Longs.tryParse(v.substring(i2 + 1));
       if (l == null) {
         logger.atWarning().log(
             "Failed to parse timestamp of reviewer by email field from change %s: %s",

java/com/google/gerrit/server/mail/MailUtil.java

@@ -124,7 +124,7 @@ public class MailUtil {
       return Pattern.compile(".*");
     }
 
-    StringBuilder sb = new StringBuilder("");
+    StringBuilder sb = new StringBuilder();
     for (String domain : domains) {
       String quoted = "\\Q" + domain.replace("\\E", "\\E\\\\E\\Q") + "\\E|";
       sb.append(quoted.replace("*", "\\E.*\\Q"));

java/com/google/gerrit/server/notedb/NoteDbUtil.java

@@ -33,7 +33,7 @@ public class NoteDbUtil {
     String email = ident.getEmailAddress();
     int at = email.indexOf('@');
     if (at >= 0) {
-      String host = email.substring(at + 1, email.length());
+      String host = email.substring(at + 1);
       if (host.equals(serverId)) {
         Integer id = Ints.tryParse(email.substring(0, at));
         if (id != null) {

java/gerrit/PRED_commit_edits_2.java

@@ -97,11 +97,7 @@ public class PRED_commit_edits_2 extends Predicate.P2 {
 
         if (fileRegex.matcher(newName).find()
             || (oldName != null && fileRegex.matcher(oldName).find())) {
-          // This cast still seems to be needed on JDK 8 as workaround for:
+          List<Edit> edits = entry.getEdits();
-          // https://bugs.openjdk.java.net/browse/JDK-8039214
-          @SuppressWarnings("cast")
-          List<Edit> edits = (List<Edit>) entry.getEdits();
-
           if (edits.isEmpty()) {
             continue;
           }

javatests/com/google/gerrit/acceptance/git/GitmodulesIT.java

@@ -47,7 +47,7 @@ public class GitmodulesIT extends AbstractDaemonTest {
         .commit()
         .insertChangeId()
         .message("subject: adding new subscription")
-        .add(".gitmodules", config.toText().toString())
+        .add(".gitmodules", config.toText())
         .create();
 
     exception.expectMessage(expectedErrorMessage);