Example usage for java.util Set addAll

Introduction

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

Prototype

boolean addAll(Collection<? extends E> c);

Source Link

Document

Adds all of the elements in the specified collection to this set if they're not already present (optional operation).

Usage

From source file:Main.java

public static <A> Set<A> makeSet(Collection<A> xs) {
    if (xs.size() == 0)
        return Collections.<A>emptySet();
    else if (xs.size() == 1)
        return Collections.singleton(xs.iterator().next());
    else {/*from w w w.  j  a  v  a  2 s  .co m*/
        Set<A> set = new HashSet<A>(xs.size());
        set.addAll(xs);
        return set;
    }
}

From source file:Main.java

public static Set<?> asSet(Object o) {
    if (o instanceof Set) {
        return (Set<?>) o;
    } else if (o instanceof Collection) {
        Set<Object> set = createDefaultSet();
        set.addAll((Collection<?>) o);
        return set;
    } else {/* www .  j  ava 2s .  c om*/
        Set<Object> set = createDefaultSet();
        set.add(o);
        return set;
    }
}

From source file:Main.java

public static <K> Set<K> createHashSet(K[] ks) {
    Set<K> kSet = new HashSet<K>(ks.length, 1);
    kSet.addAll(Arrays.asList(ks));
    return kSet;//from  www. j  a va 2  s .  c  o  m
}

From source file:Main.java

/**
 * Returns a {@link Set} containing the union of the given {@link Set}s.
 * //from   w w  w.j av a 2 s  . c o m
 * @param <T> type of items.
 * @param a the first set, must not be <code>null</code>
 * @param b the second set, must not be <code>null</code>
 * @return the union of the two.
 */
public static <T> Set<T> union(final Set<? extends T> a, final Set<? extends T> b) {
    final Set<T> res = new HashSet<T>(a);
    if (a != b)
        res.addAll(b);
    return res;
}

From source file:SetOps.java

/**
 * //from   ww w  . j a  v  a 2s.  co m
 * @param <T>
 * @param s1
 * @param s2
 * @return the union of s1 and s2. (The union of two sets is the set
 *         containing all of the elements contained in either set.)
 */
public static <T> Set<T> union(Set<T> s1, Set<T> s2) {
    Set<T> union = new LinkedHashSet<T>(s1);
    union.addAll(s2);
    return union;
}

From source file:Main.java

/**
 * Removes the duplicates by modifying the source list and keeping the order of the elements.
 *
 * @param <T>//  w  w  w.  j ava 2s.  c  o m
 *            the generic type
 * @param list
 *            the list
 * @return the same object as the argument
 */
public static <T> List<T> removeDuplicates(List<T> list) {
    Set<T> temp = createLinkedHashSet(list.size());
    temp.addAll(list);
    list.clear();
    list.addAll(temp);
    return list;
}

From source file:Main.java

/**
 * This method performs a union on two collections of elements as per definition of the <i>union</i> operation in set theory. 
 * The resulting collection guarantees unique membership as per implementation of the Java {@link java.util.Set} interface.
 * This is a null-safe operation./*from w  w w  .ja va 2  s  .c o  m*/
 * @see <a href="http://en.wikipedia.org/wiki/Union_(set_theory)">Union (set theory)</a>
 * @param firstGroup Collection to be used.
 * @param secondGroup Collection to be used.
 * @return The resulting collection containing all distinct members from the two groups.
 */
public static <T> Collection<T> union(Collection<T> firstGroup, Collection<T> secondGroup) {

    if (firstGroup == null)
        return secondGroup;
    else if (secondGroup == null)
        return firstGroup;
    else {
        Set<T> firstSet = new HashSet<T>(firstGroup);
        firstSet.addAll(secondGroup);
        return firstSet;
    }
}

From source file:Main.java

/**
 * This method performs a delta operation on two collections of elements; i.e. it returns a collection with elements that
 * are not found in the collection returns by the CollectionHelper.intersect() method.
 * The resulting collection guarantees unique membership as per implementation of the Java {@link java.util.Set} interface.
 * This is a null-safe operation.// ww w . j av  a  2 s. c om
 * @param firstGroup Collection to be used.
 * @param secondGroup Collection to be used.
 * @return The resulting collection which represents the delta of the two groups.
 */
public static <T> Collection<T> delta(Collection<T> groupOne, Collection<T> groupTwo) {

    if (groupOne == null)
        return groupTwo;
    else if (groupTwo == null)
        return groupOne;

    Set<T> delta = new HashSet<T>();
    delta.addAll(findGroupOneDelta(groupOne, groupTwo));
    delta.addAll(findGroupTwoDelta(groupTwo, groupOne));
    return delta;
}

From source file:Main.java

/**
 * Make UNION operation between 2 {@link Collection}
 * /*from  www  .  ja v a2  s .c om*/
 * @param a
 * @param b
 * @return
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public static Collection union(final Collection a, final Collection b) {
    ArrayList list = new ArrayList();
    Map mapa = getCardinalityMap(a);
    Map mapb = getCardinalityMap(b);
    Set elts = new LinkedHashSet(a);
    elts.addAll(b);
    Iterator it = elts.iterator();
    while (it.hasNext()) {
        Object obj = it.next();
        for (int i = 0, m = Math.max(getFreq(obj, mapa), getFreq(obj, mapb)); i < m; i++) {
            list.add(obj);
        }
    }
    return list;
}

From source file:Main.java

/**
 * Make INTERSECTION operation between 2 {@link Collection}
 * //from www.j av  a 2s .com
 * @param a
 * @param b
 * @return
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public static Collection intersection(final Collection a, final Collection b) {
    ArrayList list = new ArrayList();
    Map mapa = getCardinalityMap(a);
    Map mapb = getCardinalityMap(b);
    Set elts = new LinkedHashSet(a);
    elts.addAll(b);
    Iterator it = elts.iterator();
    while (it.hasNext()) {
        Object obj = it.next();
        for (int i = 0, m = Math.min(getFreq(obj, mapa), getFreq(obj, mapb)); i < m; i++) {
            list.add(obj);
        }
    }
    return list;
}