Java Utililty Methods Collection Search

List of utility methods to do Collection Search

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Description

The list of methods to do Collection Search are organized into topic(s).

Method

booleanhasLength(final Collection collection)
has Length 
return collection != null && !collection.isEmpty();
booleanhasNoValue(Collection collection)
has No Value 
if (collection == null)
    return true;
if (collection.isEmpty())
    return true;
for (Object val : collection) {
    if (val == null)
        return true;
    if (val instanceof String && ((String) val).isEmpty())
...
booleanhasOneItem(final Collection col)
has One Item 
return col != null && col.size() == 1;
booleanhasOtherThan(Collection a, Collection b)
Return true if a contains at least one element which is not contained in b 
if (a.size() > b.size())
    return true;
return !b.containsAll(a);
booleanhasValidElement(Collection collection)
has Valid Element 
for (Object object : collection) {
    if (object != null) {
        return true;
return false;
booleanhasValue(Collection collection)
Is this a non-null collection w/ at least 1 item in it? 
return (collection != null) && collection.size() > 0;
intindexOf(Collection stringCollection, String str)
Returns index of string in a string collection 
if (str != null && stringCollection != null) {
    int i = 0;
    for (String s : stringCollection) {
        if (s.equals(str)) {
            return i;
        i++;
return -1;
intindexOf(final Collection c, final Object elem)
Get the index position of an element in a collection 
if (c instanceof List) {
    return ((List) c).indexOf(elem);
} else {
    int index = 0;
    for (Object element : c) {
        if (element == elem) {
            return index;
        } else {
...
intindexOfInstance(final Collection collection, final T instance)
Determine the index position of the first occurrence of the given object instance in the given collection. 
if (collection != null && !collection.isEmpty()) {
    int index = 0;
    for (final T collectionElement : collection) {
        if (collectionElement == instance) {
            return index;
        index++;
return -1;
intindexOfObjectIdentity(Collection collection, Object object)
Returns the index position of the first occurring object within the Collection . 
int retval = -1;
if (collection != null) {
    Iterator<E> iterator = collection.iterator();
    if (iterator != null) {
        int indexPosition = 0;
        while (retval < 0 && iterator.hasNext()) {
            E element = iterator.next();
            if (element == object) {
...