HADOOP-18266. Using HashSet/ TreeSet Constructor for hadoop-common

hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/util/KerberosUtil.java

@@ -236,7 +236,7 @@ public static final String getServicePrincipal(String service,
    */
   static final String[] getPrincipalNames(String keytabFileName) throws IOException {
     Keytab keytab = Keytab.loadKeytab(new File(keytabFileName));
-    Set<String> principals = new HashSet<String>();
+    Set<String> principals = new HashSet<>();
     List<PrincipalName> entries = keytab.getPrincipals();
     for (PrincipalName entry : entries) {
       principals.add(entry.getName().replace("\\", "/"));

hadoop-common-project/hadoop-auth/src/test/java/org/apache/hadoop/security/authentication/KerberosTestUtils.java

@@ -108,9 +108,9 @@ public AppConfigurationEntry[] getAppConfigurationEntry(String name) {
   public static <T> T doAs(String principal, final Callable<T> callable) throws Exception {
     LoginContext loginContext = null;
     try {
-      Set<Principal> principals = new HashSet<Principal>();
+      Set<Principal> principals = new HashSet<>();
       principals.add(new KerberosPrincipal(KerberosTestUtils.getClientPrincipal()));
-      Subject subject = new Subject(false, principals, new HashSet<Object>(), new HashSet<Object>());
+      Subject subject = new Subject(false, principals, new HashSet<>(), new HashSet<>());
       loginContext = new LoginContext("", subject, null, new KerberosConfiguration(principal));
       loginContext.login();
       subject = loginContext.getSubject();

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java

@@ -774,7 +774,7 @@ private void updatePropertiesWithDeprecatedKeys(
   private void handleDeprecation() {
     LOG.debug("Handling deprecation for all properties in config...");
     DeprecationContext deprecations = deprecationContext.get();
-    Set<Object> keys = new HashSet<Object>();
+    Set<Object> keys = new HashSet<>();
     keys.addAll(getProps().keySet());
     for (Object item: keys) {
       LOG.debug("Handling deprecation for " + (String)item);

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileContext.java

@@ -2372,8 +2372,7 @@ public FileStatus next(final AbstractFileSystem fs, final Path p)
   Set<AbstractFileSystem> resolveAbstractFileSystems(final Path f)
       throws IOException {
     final Path absF = fixRelativePart(f);
-    final HashSet<AbstractFileSystem> result 
-      = new HashSet<AbstractFileSystem>();
+    final HashSet<AbstractFileSystem> result = new HashSet<>();
     new FSLinkResolver<Void>() {
       @Override
       public Void next(final AbstractFileSystem fs, final Path p)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPConnectionPool.java

@@ -76,7 +76,7 @@ synchronized void returnToPool(ChannelSftp channel) {
     ConnectionInfo info = con2infoMap.get(channel);
     HashSet<ChannelSftp> cons = idleConnections.get(info);
     if (cons == null) {
-      cons = new HashSet<ChannelSftp>();
+      cons = new HashSet<>();
       idleConnections.put(info, cons);
     }
     cons.add(channel);
@@ -94,7 +94,7 @@ synchronized void shutdown() {
     Set<ChannelSftp> cons = con2infoMap.keySet();
     if (cons != null && cons.size() > 0) {
       // make a copy since we need to modify the underlying Map
-      Set<ChannelSftp> copy = new HashSet<ChannelSftp>(cons);
+      Set<ChannelSftp> copy = new HashSet<>(cons);
       // Initiate disconnect from all outstanding connections
       for (ChannelSftp con : copy) {
         try {

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/CommandFormat.java

@@ -165,7 +165,7 @@ public String getOptValue(String option) {
    * @return Set{@literal <}String{@literal >} of the enabled options
    */
   public Set<String> getOpts() {
-    Set<String> optSet = new HashSet<String>();
+    Set<String> optSet = new HashSet<>();
     for (Map.Entry<String, Boolean> entry : options.entrySet()) {
       if (entry.getValue()) {
         optSet.add(entry.getKey());

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/find/Find.java

@@ -96,7 +96,7 @@ private static void addExpression(Class<?> clazz) {
   private Expression rootExpression;
 
   /** Set of path items returning a {@link Result#STOP} result. */
-  private HashSet<Path> stopPaths = new HashSet<Path>();
+  private HashSet<Path> stopPaths = new HashSet<>();
 
   /** Register the expressions with the expression factory. */
   private static void registerExpressions(ExpressionFactory factory) {

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java

@@ -1037,7 +1037,7 @@ public FileSystem[] getChildFileSystems() {
     List<InodeTree.MountPoint<FileSystem>> mountPoints =
         fsState.getMountPoints();
     Map<String, FileSystem> fsMap = initializeMountedFileSystems(mountPoints);
-    Set<FileSystem> children = new HashSet<FileSystem>();
+    Set<FileSystem> children = new HashSet<>();
     for (InodeTree.MountPoint<FileSystem> mountPoint : mountPoints) {
       FileSystem targetFs = fsMap.get(mountPoint.src);
       children.addAll(Arrays.asList(targetFs.getChildFileSystems()));

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/CodecPool.java

@@ -109,7 +109,7 @@ private static <T> boolean payback(Map<Class<T>, Set<T>> pool, T codec) {
       synchronized (pool) {
         codecSet = pool.get(codecClass);
         if (codecSet == null) {
-          codecSet = new HashSet<T>();
+          codecSet = new HashSet<>();
           pool.put(codecClass, codecSet);
         }
       }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/serializer/avro/AvroReflectSerialization.java

@@ -64,7 +64,7 @@ public synchronized boolean accept(Class<?> c) {
 
   private void getPackages() {
     String[] pkgList  = getConf().getStrings(AVRO_REFLECT_PACKAGES);
-    packages = new HashSet<String>();
+    packages = new HashSet<>();
     if (pkgList != null) {
       for (String pkg : pkgList) {
         packages.add(pkg.trim());

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/ProtocolProxy.java

@@ -69,7 +69,7 @@ private void fetchServerMethods(Method method) throws IOException {
     }
     int[] serverMethodsCodes = serverInfo.getMethods();
     if (serverMethodsCodes != null) {
-      serverMethods = new HashSet<Integer>(serverMethodsCodes.length);
+      serverMethods = new HashSet<>(serverMethodsCodes.length);
       for (int m : serverMethodsCodes) {
         this.serverMethods.add(Integer.valueOf(m));
       }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableRates.java

@@ -19,11 +19,10 @@
 package org.apache.hadoop.metrics2.lib;
 
 import java.lang.reflect.Method;
+import java.util.HashSet;
 import java.util.Set;
 
 import static org.apache.hadoop.util.Preconditions.*;
-import org.apache.hadoop.util.Sets;
-
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.metrics2.MetricsRecordBuilder;
@@ -44,7 +43,7 @@
 public class MutableRates extends MutableMetric {
   static final Logger LOG = LoggerFactory.getLogger(MutableRates.class);
   private final MetricsRegistry registry;
-  private final Set<Class<?>> protocolCache = Sets.newHashSet();
+  private final Set<Class<?>> protocolCache = new HashSet<>();
 
   MutableRates(MetricsRegistry registry) {
     this.registry = checkNotNull(registry, "metrics registry");

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableRatesWithAggregation.java

@@ -18,9 +18,9 @@
 
 package org.apache.hadoop.metrics2.lib;
 
-import org.apache.hadoop.util.Sets;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Method;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
@@ -52,7 +52,7 @@ public class MutableRatesWithAggregation extends MutableMetric {
       LoggerFactory.getLogger(MutableRatesWithAggregation.class);
   private final Map<String, MutableRate> globalMetrics =
       new ConcurrentHashMap<>();
-  private final Set<Class<?>> protocolCache = Sets.newHashSet();
+  private final Set<Class<?>> protocolCache = new HashSet<>();
 
   private final ConcurrentLinkedDeque<WeakReference<ConcurrentMap<String, ThreadSafeSampleStat>>>
       weakReferenceQueue = new ConcurrentLinkedDeque<>();

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/AbstractDNSToSwitchMapping.java

@@ -115,7 +115,7 @@ public String dumpTopology() {
     builder.append("Mapping: ").append(toString()).append("\n");
     if (rack != null) {
       builder.append("Map:\n");
-      Set<String> switches = new HashSet<String>();
+      Set<String> switches = new HashSet<>();
       for (Map.Entry<String, String> entry : rack.entrySet()) {
         builder.append("  ")
             .append(entry.getKey())

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetworkTopology.java

@@ -1086,7 +1086,7 @@ private void interAddNodeWithEmptyRack(Node node) {
     String rackname = node.getNetworkLocation();
     Set<String> nodes = rackMap.get(rackname);
     if (nodes == null) {
-      nodes = new HashSet<String>();
+      nodes = new HashSet<>();
     }
     if (!decommissionNodes.contains(node.getName())) {
       nodes.add(node.getName());

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/CompositeGroupsMapping.java

@@ -109,7 +109,7 @@ public void cacheGroupsAdd(List<String> groups) throws IOException {
 
   @Override
   public synchronized Set<String> getGroupsSet(String user) throws IOException {
-    Set<String> groupSet = new HashSet<String>();
+    Set<String> groupSet = new HashSet<>();
 
     Set<String> groups = null;
     for (GroupMappingServiceProvider provider : providersList) {

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/NetgroupCache.java

@@ -65,7 +65,7 @@ public static List<String> getNetgroupNames() {
   }
 
   private static Set<String> getGroups() {
-    Set<String> allGroups = new HashSet<String> ();
+    Set<String> allGroups = new HashSet<>();
     for (Set<String> userGroups : userToNetgroupsMap.values()) {
       allGroups.addAll(userGroups);
     }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/authorize/AccessControlList.java

@@ -105,8 +105,8 @@ public AccessControlList(String users, String groups) {
    * @param userGroupStrings build ACL from array of Strings
    */
   private void buildACL(String[] userGroupStrings) {
-    users = new HashSet<String>();
-    groups = new HashSet<String>();
+    users = new HashSet<>();
+    groups = new HashSet<>();
     for (String aclPart : userGroupStrings) {
       if (aclPart != null && isWildCardACLValue(aclPart)) {
         allAllowed = true;

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/authorize/ProxyServers.java

@@ -33,7 +33,7 @@ public static void refresh() {
   }
 
   public static void refresh(Configuration conf){
-    Collection<String> tempServers = new HashSet<String>();
+    Collection<String> tempServers = new HashSet<>();
     // trusted proxy servers such as http proxies
     for (String host : conf.getTrimmedStrings(CONF_HADOOP_PROXYSERVERS)) {
       InetSocketAddress addr = new InetSocketAddress(host, 0);

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/http/RestCsrfPreventionFilter.java

@@ -94,15 +94,15 @@ public void init(FilterConfig filterConfig) throws ServletException {
 
   void parseBrowserUserAgents(String userAgents) {
     String[] agentsArray =  userAgents.split(",");
-    browserUserAgents = new HashSet<Pattern>();
+    browserUserAgents = new HashSet<>();
     for (String patternString : agentsArray) {
       browserUserAgents.add(Pattern.compile(patternString));
     }
   }
 
   void parseMethodsToIgnore(String mti) {
     String[] methods = mti.split(",");
-    methodsToIgnore = new HashSet<String>();
+    methodsToIgnore = new HashSet<>();
     for (int i = 0; i < methods.length; i++) {
       methodsToIgnore.add(methods[i]);
     }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/AbstractDelegationTokenSecretManager.java

@@ -716,7 +716,7 @@ public String getTrackingId() {
   /** Remove expired delegation tokens from cache */
   private void removeExpiredToken() throws IOException {
     long now = Time.now();
-    Set<TokenIdent> expiredTokens = new HashSet<TokenIdent>();
+    Set<TokenIdent> expiredTokens = new HashSet<>();
     synchronized (this) {
       Iterator<Map.Entry<TokenIdent, DelegationTokenInformation>> i =
           currentTokens.entrySet().iterator();

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/web/DelegationTokenAuthenticationHandler.java

@@ -89,7 +89,7 @@ public abstract class DelegationTokenAuthenticationHandler
 
   public static final String TOKEN_KIND = PREFIX + "token-kind";
 
-  private static final Set<String> DELEGATION_TOKEN_OPS = new HashSet<String>();
+  private static final Set<String> DELEGATION_TOKEN_OPS = new HashSet<>();
 
   public static final String DELEGATION_TOKEN_UGI_ATTRIBUTE =
       "hadoop.security.delegation-token.ugi";

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/FileBasedIPList.java

@@ -58,7 +58,7 @@ public FileBasedIPList(String fileName) {
       lines = null;
     }
     if (lines != null) {
-      addressList = new MachineList(new HashSet<String>(Arrays.asList(lines)));
+      addressList = new MachineList(new HashSet<>(Arrays.asList(lines)));
     } else {
       addressList = null;
     }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/HostsFileReader.java

@@ -135,7 +135,7 @@ public static void readFileToMapWithFileInputStream(String type,
     if (xmlInput) {
       readXmlFileToMapWithFileInputStream(type, filename, inputStream, map);
     } else {
-      HashSet<String> nodes = new HashSet<String>();
+      HashSet<String> nodes = new HashSet<>();
       readFileToSetWithFileInputStream(type, filename, inputStream, nodes);
       for (String node : nodes) {
         map.put(node, null);

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ShutdownHookManager.java

@@ -249,7 +249,7 @@ TimeUnit getTimeUnit() {
   }
 
   private final Set<HookEntry> hooks =
-      Collections.synchronizedSet(new HashSet<HookEntry>());
+      Collections.synchronizedSet(new HashSet<>());
 
   private AtomicBoolean shutdownInProgress = new AtomicBoolean(false);
 

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/conf/TestCommonConfigurationFields.java

@@ -80,9 +80,9 @@ public void initializeMemberVariables() {
         };
 
     // Initialize used variables
-    xmlPropsToSkipCompare = new HashSet<String>();
-    xmlPrefixToSkipCompare = new HashSet<String>();
-    configurationPropsToSkipCompare = new HashSet<String>();
+    xmlPropsToSkipCompare = new HashSet<>();
+    xmlPrefixToSkipCompare = new HashSet<>();
+    configurationPropsToSkipCompare = new HashSet<>();
 
     // Set error modes
     errorIfMissingConfigProps = true;

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/key/TestValueQueue.java

@@ -18,6 +18,8 @@
 package org.apache.hadoop.crypto.key;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.HashSet;
 import java.util.Queue;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeoutException;
@@ -32,7 +34,6 @@
 import org.junit.Assert;
 import org.junit.Test;
 
-import org.apache.hadoop.util.Sets;
 
 public class TestValueQueue {
   Logger LOG = LoggerFactory.getLogger(TestValueQueue.class);
@@ -103,10 +104,10 @@ public void testWarmUp() throws Exception {
     Assert.assertEquals(5, fillInfos[0].num);
     Assert.assertEquals(5, fillInfos[1].num);
     Assert.assertEquals(5, fillInfos[2].num);
-    Assert.assertEquals(Sets.newHashSet("k1", "k2", "k3"),
-        Sets.newHashSet(fillInfos[0].key,
+    Assert.assertEquals(new HashSet<>(Arrays.asList("k1", "k2", "k3")),
+        new HashSet<>(Arrays.asList(fillInfos[0].key,
             fillInfos[1].key,
-            fillInfos[2].key));
+            fillInfos[2].key)));
     vq.shutdown();
   }
 

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/key/kms/TestLoadBalancingKMSClientProvider.java

@@ -39,6 +39,8 @@
 import java.security.NoSuchAlgorithmException;
 import java.security.PrivilegedExceptionAction;
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
@@ -65,7 +67,6 @@
 import org.junit.rules.Timeout;
 import org.mockito.Mockito;
 
-import org.apache.hadoop.util.Sets;
 
 public class TestLoadBalancingKMSClientProvider {
 
@@ -86,34 +87,34 @@ public void testCreation() throws Exception {
     KMSClientProvider[] providers =
         ((LoadBalancingKMSClientProvider) kp).getProviders();
     assertEquals(1, providers.length);
-    assertEquals(Sets.newHashSet("http://host1:9600/kms/foo/v1/"),
-        Sets.newHashSet(providers[0].getKMSUrl()));
+    assertEquals(new HashSet<>(Collections.singleton("http://host1:9600/kms/foo/v1/")),
+        new HashSet<>(Collections.singleton(providers[0].getKMSUrl())));
 
     kp = new KMSClientProvider.Factory().createProvider(new URI(
         "kms://http@host1;host2;host3:9600/kms/foo"), conf);
     assertTrue(kp instanceof LoadBalancingKMSClientProvider);
     providers =
         ((LoadBalancingKMSClientProvider) kp).getProviders();
     assertEquals(3, providers.length);
-    assertEquals(Sets.newHashSet("http://host1:9600/kms/foo/v1/",
+    assertEquals(new HashSet<>(Arrays.asList("http://host1:9600/kms/foo/v1/",
         "http://host2:9600/kms/foo/v1/",
-        "http://host3:9600/kms/foo/v1/"),
-        Sets.newHashSet(providers[0].getKMSUrl(),
+        "http://host3:9600/kms/foo/v1/")),
+        new HashSet<>(Arrays.asList(providers[0].getKMSUrl(),
             providers[1].getKMSUrl(),
-            providers[2].getKMSUrl()));
+            providers[2].getKMSUrl())));
 
     kp = new KMSClientProvider.Factory().createProvider(new URI(
         "kms://http@host1;host2;host3:9600/kms/foo"), conf);
     assertTrue(kp instanceof LoadBalancingKMSClientProvider);
     providers =
         ((LoadBalancingKMSClientProvider) kp).getProviders();
     assertEquals(3, providers.length);
-    assertEquals(Sets.newHashSet("http://host1:9600/kms/foo/v1/",
+    assertEquals(new HashSet<>(Arrays.asList("http://host1:9600/kms/foo/v1/",
         "http://host2:9600/kms/foo/v1/",
-        "http://host3:9600/kms/foo/v1/"),
-        Sets.newHashSet(providers[0].getKMSUrl(),
+        "http://host3:9600/kms/foo/v1/")),
+        new HashSet<>(Arrays.asList(providers[0].getKMSUrl(),
             providers[1].getKMSUrl(),
-            providers[2].getKMSUrl()));
+            providers[2].getKMSUrl())));
   }
 
   @Test

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestCommandFormat.java

@@ -43,9 +43,9 @@ public class TestCommandFormat {
 
   @Before
   public void setUp() {
-    args = new ArrayList<String>();
-    expectedOpts = new HashSet<String>();
-    expectedArgs = new ArrayList<String>();
+    args = new ArrayList<>();
+    expectedOpts = new HashSet<>();
+    expectedArgs = new ArrayList<>();
   }
 
   @Test
@@ -205,6 +205,6 @@ private static List<String> listOf(String ... objects) {
   }
 
   private static Set<String> setOf(String ... objects) {
-    return new HashSet<String>(listOf(objects));
+    return new HashSet<>(listOf(objects));
   }
 }