Example usage for java.util Collection isEmpty

Introduction

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

Prototype

boolean isEmpty();

Source Link

Document

Returns true if this collection contains no elements.

Usage

From source file:Main.java

/**
 * Return <code>true</code> if the supplied Collection is <code>null</code>
 * or empty. Otherwise, return <code>false</code>.
 * /* w  ww .j a v a  2 s  .  c o m*/
 * @param collection
 *            the Collection to check
 * @return whether the given Collection is empty
 */
public static boolean isEmpty(final Collection<?> collection) {
    return ((collection == null) || collection.isEmpty());
}

From source file:Main.java

public static <T> boolean containsAny(Collection<T> collection, Collection<T> query) {
    if (collection == null || collection.isEmpty() || query == null || query.isEmpty())
        return false;
    for (T val : query) {
        if (collection.contains(val))
            return true;
    }//from   w w w  .j av a 2s.  c  o m
    return false;
}

From source file:Main.java

public static <V> V getRandom(Collection<V> collection) {

    if (collection.isEmpty()) {
        return null;
    }// w ww. j  a  va2s .  co  m

    int randIdx = (int) Math.round(Math.random() * (collection.size() - 1));
    int count = 0;
    Iterator<V> iterator = collection.iterator();
    while (iterator.hasNext()) {
        V current = iterator.next();
        if (count == randIdx) {
            return current;
        }
        count++;
    }

    throw new RuntimeException("Shouldn't happen");
}

From source file:Main.java

public static boolean isEmpty(Collection<?>... colls) {
    boolean result = false;

    for (Collection<?> coll : colls) {
        if (null == coll || coll.isEmpty()) {
            result = true;//from w w  w. j  a v  a2 s .c  o m
            break;
        }
    }

    return result;
}

From source file:Main.java

public static <T> boolean retainAllByValue(Collection<T> c1, Collection<? extends T> c2) {
    if (c1 == null || c2 == null || c1.isEmpty() || c2.isEmpty())
        return false;
    List<T> itemsToRemove = new ArrayList<T>();
    for (T item : c1) {
        if (!containsByValue(c2, item))
            itemsToRemove.add(item);/*from   ww w .ja v a 2 s  . c o  m*/
    }
    c1.removeAll(itemsToRemove);
    return (!itemsToRemove.isEmpty());
}

From source file:Main.java

public static boolean isEmpty(final Collection<?> c) {
    return c == null || c.isEmpty();
}

From source file:Main.java

private static <E> boolean fallBackToStandardImplementation(final Collection<E> coll, final int limit) {
    return limit >= coll.size() || limit < 0 || coll.isEmpty();
}

From source file:Main.java

/**
 * Checks if is empty./*  w ww  .  j  a v a 2  s.  c o m*/
 *
 * @param value
 *            the value
 * @return true, if is empty
 */
public static boolean isEmpty(Collection<?> value) {
    if (value == null)
        return true;
    return value.isEmpty();
}

From source file:Main.java

public static <T> boolean isEmptyOrNull(Collection<T> collection) {
    return collection == null || collection.isEmpty();
}

From source file:Main.java

public static <T> List<T> sub(Collection<T> list, int start, int end) {
    if (list == null || list.isEmpty()) {
        return null;
    }/*from   w w w  . j a v  a2s  . c o m*/

    return sub(new ArrayList<T>(list), start, end);
}