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>coll</code> if it is non-null and non-empty. Otherwise,
 * returns a list with a single null value.
 *//*  w w w.  jav a  2 s. c o m*/
private static Collection<String> emptyAsSingletonNull(Collection<String> coll) {
    if (coll == null || coll.isEmpty()) {
        return Collections.singletonList(null);
    } else {
        return coll;
    }
}

From source file:Main.java

/**
 * *************************************************************
 *//*from w w  w .j a va  2s . c  o  m*/

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

From source file:Main.java

/**
 * Utility method to check if a collection is null or empty
 * /*from   w ww  .  j  a  va 2s.c o  m*/
 * @param collection
 * @return
 */
public static boolean isNullOrEmpty(Collection<?> collection) {
    if (collection == null || collection.isEmpty())
        return true;
    return false;
}

From source file:Main.java

@SuppressWarnings("rawtypes")
public static boolean isNotEmpty(Collection collection) {
    return (collection != null) && !(collection.isEmpty());
}

From source file:Main.java

/**
 * INTERNAL: Gets the first object in the collection. If the
 * collection does not contain any elements NoSuchElementException
 * is thrown.<p>/* w w w.  ja v a2 s  .c om*/
 *
 * @since 1.3.4
 */
public static <T> T getFirstElement(Collection<T> coll) {
    if ((coll == null) || coll.isEmpty())
        throw new NoSuchElementException();
    return coll.iterator().next();
}

From source file:Main.java

/**
 * Return the last element of a collection. This method iterates over the complete collection to found
 * the last element./*from   w ww .  j  ava 2 s.c om*/
 *
 * @param collection The collection to get the last element from.
 * @param <T> The type of value.
 * @return The last element of the collection. If there is no element, the method return null.
 */
public static <T> T last(Collection<T> collection) {
    if (collection.isEmpty()) {
        return null;
    }

    Iterator<T> iterator = collection.iterator();

    for (int i = 0; i < collection.size() - 1; i++) {
        iterator.next();
    }

    return iterator.next();
}

From source file:Main.java

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

From source file:Main.java

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

From source file:Main.java

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

From source file:Main.java

public static Collection Coalesce(Collection collection, Collection alternative) {
    if (collection != null && !collection.isEmpty())
        return collection;
    return alternative;
}