Issue checkstyle#3433: Get rid of com.google.common.collect.Sets

src/main/java/com/puppycrawl/tools/checkstyle/Checker.java

@@ -23,16 +23,17 @@
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.nio.charset.Charset;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Set;
 import java.util.SortedSet;
+import java.util.TreeSet;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
 import com.puppycrawl.tools.checkstyle.api.AuditEvent;
 import com.puppycrawl.tools.checkstyle.api.AuditListener;
 import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
@@ -214,7 +215,7 @@ public int process(List<File> files) throws CheckstyleException {
      *         checks and filters.
      */
     private Set<String> getExternalResourceLocations() {
-        final Set<String> externalResources = Sets.newHashSet();
+        final Set<String> externalResources = new HashSet<>();
         fileSetChecks.stream().filter(check -> check instanceof ExternalResourceHolder)
             .forEach(check -> {
                 final Set<String> locations =
@@ -290,7 +291,7 @@ private void processFiles(List<File> files) throws CheckstyleException {
      * @throws CheckstyleException if error condition within Checkstyle occurs.
      */
     private SortedSet<LocalizedMessage> processFile(File file) throws CheckstyleException {
-        final SortedSet<LocalizedMessage> fileMessages = Sets.newTreeSet();
+        final SortedSet<LocalizedMessage> fileMessages = new TreeSet<>();
         try {
             final FileText theText = new FileText(file.getAbsoluteFile(), charset);
             for (final FileSetCheck fsc : fileSetChecks) {

src/main/java/com/puppycrawl/tools/checkstyle/PackageNamesLoader.java

@@ -27,6 +27,7 @@
 import java.util.Deque;
 import java.util.Enumeration;
 import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import javax.xml.parsers.ParserConfigurationException;
@@ -35,7 +36,6 @@
 import org.xml.sax.InputSource;
 import org.xml.sax.SAXException;
 
-import com.google.common.collect.Sets;
 import com.google.common.io.Closeables;
 import com.puppycrawl.tools.checkstyle.api.AbstractLoader;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
@@ -68,7 +68,7 @@ public final class PackageNamesLoader
     private final Deque<String> packageStack = new ArrayDeque<>();
 
     /** The fully qualified package names. */
-    private final Set<String> packageNames = Sets.newLinkedHashSet();
+    private final Set<String> packageNames = new LinkedHashSet<>();
 
     /**
      * Creates a new {@code PackageNamesLoader} instance.

src/main/java/com/puppycrawl/tools/checkstyle/PackageObjectFactory.java

@@ -20,14 +20,15 @@
 package com.puppycrawl.tools.checkstyle;
 
 import java.lang.reflect.Constructor;
+import java.util.HashSet;
 import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.stream.Collectors;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-import com.google.common.collect.Sets;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
 import com.puppycrawl.tools.checkstyle.api.LocalizedMessage;
 
@@ -68,7 +69,7 @@ public PackageObjectFactory(Set<String> packageNames, ClassLoader moduleClassLoa
         }
 
         //create a copy of the given set, but retain ordering
-        packages = Sets.newLinkedHashSet(packageNames);
+        packages = new LinkedHashSet<>(packageNames);
         this.moduleClassLoader = moduleClassLoader;
     }
 
@@ -127,7 +128,7 @@ private Object createObjectWithIgnoringProblems(String className,
      * @return all possible name for a class.
      */
     private Set<String> getAllPossibleNames(String name) {
-        final Set<String> names = Sets.newHashSet();
+        final Set<String> names = new HashSet<>();
         names.addAll(packages.stream().map(packageName -> packageName + name)
             .collect(Collectors.toList()));
         return names;

src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java

@@ -35,12 +35,12 @@
 import java.nio.file.Paths;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.HashSet;
 import java.util.Properties;
 import java.util.Set;
 
 import javax.xml.bind.DatatypeConverter;
 
-import com.google.common.collect.Sets;
 import com.google.common.io.Closeables;
 import com.google.common.io.Flushables;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
@@ -241,7 +241,7 @@ public void putExternalResources(Set<String> locations) {
      * @return a set of {@link ExternalResource}.
      */
     private static Set<ExternalResource> loadExternalResources(Set<String> resourceLocations) {
-        final Set<ExternalResource> resources = Sets.newHashSet();
+        final Set<ExternalResource> resources = new HashSet<>();
         for (String location : resourceLocations) {
             String contentHashSum = null;
             try {

src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java

@@ -39,7 +39,6 @@
 import antlr.TokenStreamRecognitionException;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Multimap;
-import com.google.common.collect.Sets;
 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
 import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
@@ -75,10 +74,10 @@ public final class TreeWalker extends AbstractFileSetCheck implements ExternalRe
             HashMultimap.create();
 
     /** Registered ordinary checks, that don't use comment nodes. */
-    private final Set<AbstractCheck> ordinaryChecks = Sets.newHashSet();
+    private final Set<AbstractCheck> ordinaryChecks = new HashSet<>();
 
     /** Registered comment checks. */
-    private final Set<AbstractCheck> commentChecks = Sets.newHashSet();
+    private final Set<AbstractCheck> commentChecks = new HashSet<>();
 
     /** The distance between tab stops. */
     private int tabWidth = DEFAULT_TAB_WIDTH;
@@ -478,7 +477,7 @@ public Set<String> getExternalResourceLocations() {
      * @return a set of external configuration resource locations which are used by the checks set.
      */
     private static Set<String> getExternalResourceLocations(Set<AbstractCheck> checks) {
-        final Set<String> externalConfigurationResources = Sets.newHashSet();
+        final Set<String> externalConfigurationResources = new HashSet<>();
         checks.stream().filter(check -> check instanceof ExternalResourceHolder).forEach(check -> {
             final Set<String> checkExternalResources =
                 ((ExternalResourceHolder) check).getExternalResourceLocations();

src/main/java/com/puppycrawl/tools/checkstyle/api/AbstractCheck.java

@@ -20,10 +20,9 @@
 package com.puppycrawl.tools.checkstyle.api;
 
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Set;
 
-import com.google.common.collect.Sets;
-
 import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
 
 /**
@@ -38,7 +37,7 @@ public abstract class AbstractCheck extends AbstractViolationReporter {
     private static final int DEFAULT_TAB_WIDTH = 8;
 
     /** The tokens the check is interested in. */
-    private final Set<String> tokens = Sets.newHashSet();
+    private final Set<String> tokens = new HashSet<>();
 
     /** The current file contents. */
     private FileContents fileContents;

src/main/java/com/puppycrawl/tools/checkstyle/api/FilterSet.java

@@ -20,11 +20,10 @@
 package com.puppycrawl.tools.checkstyle.api;
 
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Objects;
 import java.util.Set;
 
-import com.google.common.collect.Sets;
-
 /**
  * A filter set applies filters to AuditEvents.
  * If a filter in the set rejects an AuditEvent, then the
@@ -34,7 +33,7 @@
 public class FilterSet
     implements Filter {
     /** Filter set. */
-    private final Set<Filter> filters = Sets.newHashSet();
+    private final Set<Filter> filters = new HashSet<>();
 
     /**
      * Adds a Filter to the set.

src/main/java/com/puppycrawl/tools/checkstyle/api/LocalizedMessages.java

@@ -21,23 +21,22 @@
 
 import java.util.Set;
 import java.util.SortedSet;
-
-import com.google.common.collect.Sets;
+import java.util.TreeSet;
 
 /**
  * Collection of messages.
  * @author Oliver Burn
  */
 public final class LocalizedMessages {
     /** Contains the messages logged. **/
-    private final Set<LocalizedMessage> messages = Sets.newTreeSet();
+    private final Set<LocalizedMessage> messages = new TreeSet<>();
 
     /**
      * Gets the logged messages.
      * @return the logged messages
      */
     public SortedSet<LocalizedMessage> getMessages() {
-        return Sets.newTreeSet(messages);
+        return new TreeSet<>(messages);
     }
 
     /** Reset the object. **/

src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractDeclarationCollector.java

@@ -20,13 +20,13 @@
 package com.puppycrawl.tools.checkstyle.checks;
 
 import java.util.Deque;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
 
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
@@ -243,7 +243,7 @@ private static class LexicalFrame {
          */
         protected LexicalFrame(LexicalFrame parent) {
             this.parent = parent;
-            varNames = Sets.newHashSet();
+            varNames = new HashSet<>();
         }
 
         /** Add a name to the frame.
@@ -328,10 +328,10 @@ private static class ClassFrame extends LexicalFrame {
          */
         ClassFrame(LexicalFrame parent) {
             super(parent);
-            instanceMembers = Sets.newHashSet();
-            instanceMethods = Sets.newHashSet();
-            staticMembers = Sets.newHashSet();
-            staticMethods = Sets.newHashSet();
+            instanceMembers = new HashSet<>();
+            instanceMethods = new HashSet<>();
+            staticMembers = new HashSet<>();
+            staticMethods = new HashSet<>();
         }
 
         /**

src/main/java/com/puppycrawl/tools/checkstyle/checks/AbstractTypeAwareCheck.java

@@ -21,12 +21,12 @@
 
 import java.util.ArrayDeque;
 import java.util.Deque;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
 
 import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 import com.puppycrawl.tools.checkstyle.api.FullIdent;
@@ -48,7 +48,7 @@ public abstract class AbstractTypeAwareCheck extends AbstractCheck {
     private final Deque<Map<String, AbstractClassInfo>> typeParams = new ArrayDeque<>();
 
     /** Imports details. **/
-    private final Set<String> imports = Sets.newHashSet();
+    private final Set<String> imports = new HashSet<>();
 
     /** Full identifier for package of the method. **/
     private FullIdent packageFullIdent;

src/main/java/com/puppycrawl/tools/checkstyle/checks/TrailingCommentCheck.java

@@ -19,12 +19,12 @@
 
 package com.puppycrawl.tools.checkstyle.checks;
 
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Pattern;
 
-import com.google.common.collect.Sets;
 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 import com.puppycrawl.tools.checkstyle.api.TextBlock;
@@ -158,7 +158,7 @@ public void beginTree(DetailAST rootAST) {
                 .getCppComments();
         final Map<Integer, List<TextBlock>> cComments = getFileContents()
                 .getCComments();
-        final Set<Integer> lines = Sets.newHashSet();
+        final Set<Integer> lines = new HashSet<>();
         lines.addAll(cppComments.keySet());
         lines.addAll(cComments.keySet());