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

/**
 * Method to check if the collection is empty or not.
 *
 * @param collection the collection/*from w  w  w .  j a  va 2 s.c o m*/
 * @return true if the collection is null or the collection is empty.
 */
public static Boolean isEmpty(final Collection collection) {
    return collection == null || collection.isEmpty();
}

From source file:Main.java

/**
 * Determine whether the given collection only contains a
 * single unique object./*from w w  w  .  ja  v  a 2 s  .  co m*/
 * @param coll the collection to check
 * @return <code>true</code> if the collection contains a
 * single reference or multiple references to the same
 * instance, <code>false</code> else
 */
public static boolean hasUniqueObject(Collection<?> coll) {
    if (coll.isEmpty()) {
        return false;
    }
    Object candidate = null;
    for (Iterator<?> it = coll.iterator(); it.hasNext();) {
        Object elem = it.next();
        if (candidate == null) {
            candidate = elem;
        } else if (candidate != elem) {
            return false;
        }
    }
    return true;
}

From source file:Main.java

public static <T> boolean isEmptyOrNull(Collection<T> c) {
    if (null == c)
        return true;
    return c.isEmpty();
}

From source file:Main.java

public static <T> T first(Collection<T> collection) {
    if (collection == null || collection.isEmpty()) {
        return null;
    }/* w w w  .ja v a2 s.  com*/
    return collection.iterator().next();
}

From source file:Main.java

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

From source file:Main.java

public static <T> Collection<T> isEmpty(Collection<T> collection, String messgae) {
    if (collection == null || collection.isEmpty()) {
        //TODO: Araz
        throw new IllegalArgumentException(messgae);
    }/*from www.  ja  v a  2s .co  m*/

    return collection;
}

From source file:Main.java

public static boolean isEmpty(Collection<?> collection) {
    if (collection == null || collection.isEmpty()) {
        return true;
    } else {// www.  j ava2  s. co  m
        return false;
    }
}

From source file:Main.java

public static int[] toIntArray(Collection<Integer> list) {
    if (list == null || list.isEmpty()) {
        return EMPTY_INT_ARRAY;
    }//from   www.ja va 2  s.c  o m
    int[] result = new int[list.size()];
    int i = 0;
    for (Integer integer : list) {
        result[i++] = integer;
    }
    return result;
}

From source file:Main.java

/**
 * Get comma separated string from collection
 * // ww w. ja va  2  s . c  om
 * @param strings
 * @return
 */
public static String getCommaSeparatedString(Collection<String> strings) {
    if (strings != null && !strings.isEmpty()) {
        Iterator<String> it = strings.iterator();
        StringBuilder sb = new StringBuilder(it.next());
        while (it.hasNext()) {
            sb.append("," + it.next());
        }
        return sb.toString();
    } else {
        return null;
    }
}

From source file:Main.java

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