Example usage for java.util HashSet HashSet

Introduction

In this page you can find the example usage for java.util HashSet HashSet.

Prototype

public HashSet()

Source Link

Document

Constructs a new, empty set; the backing HashMap instance has default initial capacity (16) and load factor (0.75).

Usage

From source file:Main.java

/**
 * Returns a new empty HashSet for objects of a certain type
 *///  w w w  .j  av  a2s  .co m
public static <T> HashSet<T> newHashSet() {
    return new HashSet<T>();
}

From source file:Main.java

static int countDistinctElements(List source, int position, int count) {
    List list = source.subList(position, position + count);
    Set set = new HashSet();
    set.addAll(list);//from   w w  w  .ja  v  a  2s  .co  m
    return set.size();
}

From source file:Main.java

public static <T> ArrayList<T> union(Collection<T> l1, Collection<T> l2) {
    Set<T> s = new HashSet<>();
    s.addAll(l1);/*from   w  w  w. j a v  a 2 s. c o  m*/
    s.addAll(l2);
    return new ArrayList<>(s);
}

From source file:Main.java

/**
 * @param toReturn/*from www .  j  av a  2s  . co m*/
 *          the {@link Set} to return, if it is not <code>null</code>.
 * @return the given {@link Set}, or an empty {@link Set} if the given one is
 *         empty.
 */
public static <T> Set<T> emptyIfNull(Set<T> toReturn) {
    if (toReturn == null) {
        return new HashSet<T>();
    }
    return toReturn;
}

From source file:Main.java

/**
 * Creates a list of the given type for the given elements.
 * /*w w w .ja  va  2 s. c o  m*/
 * @param <T>
 *            The type of the elements and the list.
 * @param elements
 *            The elements to add to the list.
 * @return The filled list.
 */
public static <T> Set<T> createSet(final T... elements) {
    Set<T> coll = new HashSet<T>();
    if (elements != null) {
        for (int i = 0; i < elements.length; i++) {
            coll.add(elements[i]);
        }
    }
    return coll;
}

From source file:Main.java

/**
 * Returns the set of all elements in the given collection that appear more than once.
 * @param input some collection./*  w  w  w  . java  2s .  co  m*/
 * @return the set of repeated elements.  May return an empty set, but never null.
 */
public static <T> Set<T> duplicatedElementsOf(Iterable<T> input) {
    Set<T> duplicates = new HashSet<>();
    Set<T> elementSet = new HashSet<>();
    for (T el : input) {
        if (!elementSet.add(el)) {
            duplicates.add(el);
        }
    }
    return duplicates;
}

From source file:Main.java

/**
 * Input is "daddy[8880],sindhu[8880],camille[5555]. Return List of
 * InetSocketAddress//from   www .j  a v  a 2s.  c o  m
 */
public static List<InetSocketAddress> parseCommaDelimitedHosts2(String hosts, int port_range) {

    StringTokenizer tok = new StringTokenizer(hosts, ",");
    String t;
    InetSocketAddress addr;
    Set<InetSocketAddress> retval = new HashSet<InetSocketAddress>();

    while (tok.hasMoreTokens()) {
        t = tok.nextToken().trim();
        String host = t.substring(0, t.indexOf('['));
        host = host.trim();
        int port = Integer.parseInt(t.substring(t.indexOf('[') + 1, t.indexOf(']')));
        for (int i = port; i < port + port_range; i++) {
            addr = new InetSocketAddress(host, i);
            retval.add(addr);
        }
    }
    return new LinkedList<InetSocketAddress>(retval);
}

From source file:Main.java

public static List<String> getLoggedInUsersAsList(Context context) {
    Set<String> users = PreferenceManager.getDefaultSharedPreferences(context)
            .getStringSet(LOGGED_IN_USER_PREFERENCE_KEY, new HashSet<>());
    return new ArrayList<String>(users);
}

From source file:Main.java

public static HashSet<String> getExcludedTags(Context context) {
    String tags = PreferenceManager.getDefaultSharedPreferences(context).getString("excludeTagsInheritance",
            null);//from   w ww . j  ava  2s  .c  o m

    if (tags == null)
        return null;

    HashSet<String> tagsSet = new HashSet<String>();
    for (String tag : tags.split(":")) {
        if (TextUtils.isEmpty(tag) == false)
            tagsSet.add(tag);
    }

    return tagsSet;
}

From source file:Main.java

/**
 * Answer a set containing all elements that are both in source and in query
 * Delete these elements from source Creation date: (13.10.2002 16:23:00)
 * // w w w. ja  v a 2 s.  c o m
 * @return java.util.Set
 * @param source
 *            java.util.Set
 * @param elements
 *            java.util.Collection
 */
public static Set extractFrom(Set source, Collection query) {
    Set answer = new HashSet();
    Iterator i = query.iterator();
    while (i.hasNext()) {
        Object o = i.next();
        if (source.remove(o)) {
            answer.add(o);
        }
    }
    return answer;
}