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

public static boolean isNotEmpty(final Collection<?> c) {
    return c != null && c.isEmpty() == false;
}

From source file:Main.java

/**
 * Returns a collection with the common elements in c1 and c2
 * @param <T>/* w  w w .  ja  v a  2s  . com*/
 * @param c1
 * @param c2
 * @return
 */
public static <T> Collection<T> intersect(Collection<T> c1, Collection<T> c2) {

    if (c1.isEmpty() || c2.isEmpty()) {
        return Collections.emptySet();
    }

    if (!(c2 instanceof Set) && (c1 instanceof Set || c1.size() > c2.size())) {
        //swap
        Collection<T> tmp = c1;
        c1 = c2;
        c2 = tmp;
    }

    Collection<T> result = new HashSet<T>();
    for (T obj : c1) {
        if (c2.contains(obj)) {
            result.add(obj);
        }
    }

    return result;
}

From source file:Main.java

public static boolean isEmpty(Collection<?> collection) {
    boolean result = false;
    if (collection == null || collection.isEmpty()) {
        result = true;/*from  ww w. jav a2  s .  co m*/
    }
    return result;
}

From source file:Main.java

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

From source file:Main.java

/**
 * Enforce that a Collection contains no more than one element and return that element
 * if it exists./* ww  w. ja va  2  s.  c  o  m*/
 * 
 * @param collection the Collection to examine
 * @return null if the Collection is null or empty, the Collection's single object if
 *       its size is one, or throw if its size is greater than one.
 * @throws IllegalArgumentException if the Collection contains more than one element
 */
public static <T> T singleObject(Collection<T> collection) {
    if (collection == null || collection.isEmpty())
        return null;
    if (collection.size() > 1)
        throw new IllegalArgumentException("more than one element in collection");
    return collection.iterator().next();
}

From source file:Main.java

public static boolean isEmptyOrNull(Collection<?> collection) {
    boolean retorno = false;
    if (null == collection || collection.isEmpty()) {
        retorno = true;//from  w w w  .  ja v a2 s.  c o m
    }
    return retorno;
}

From source file:Main.java

public static boolean isEmpty(Collection<?> collection) {
    return (collection == null || collection.size() == 0 || collection.isEmpty());
}

From source file:Main.java

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

From source file:Main.java

public static boolean isEmpty(Collection collection)
/*  58:    */ {//  w  w w . j  a v  a  2  s. c o m
    /*  59:132 */return (collection == null) || (collection.isEmpty());
    /*  60:    */}

From source file:Main.java

public static boolean isEmpty(Collection<?> paramCollection) {
    if ((paramCollection == null) || (paramCollection.isEmpty()))
        ;//from w  ww .  jav  a  2s .  c o  m
    for (boolean bool = true;; bool = false)
        return bool;
}