What causes "Entry does not exist: {}" in Blankj/AndroidUtilCode?

Bound the index against the known size before calling get (index < size).

Blankj/AndroidUtilCode · error · IndexOutOfBoundsException

Entry does not exist: {}

Error message

Entry does not exist: {}

What it means

Thrown by CollectionUtils.get when the object is an Iterator (or a Map/Collection, which are reduced to an iterator) and the iterator is exhausted before the requested index is reached. Note the index is decremented during iteration, so the reported value is the residual count (<= 0), not the original index. Map entries are indexed via their entrySet iterator.

Source

Thrown at lib/utilcode/src/main/java/com/blankj/utilcode/util/CollectionUtils.java:730

        if (object instanceof Map) {
            Map map = (Map) object;
            Iterator iterator = map.entrySet().iterator();
            return get(iterator, index);
        } else if (object instanceof List) {
            return ((List) object).get(index);
        } else if (object instanceof Object[]) {
            return ((Object[]) object)[index];
        } else if (object instanceof Iterator) {
            Iterator it = (Iterator) object;
            while (it.hasNext()) {
                index--;
                if (index == -1) {
                    return it.next();
                } else {
                    it.next();
                }
            }
            throw new IndexOutOfBoundsException("Entry does not exist: " + index);
        } else if (object instanceof Collection) {
            Iterator iterator = ((Collection) object).iterator();
            return get(iterator, index);
        } else if (object instanceof Enumeration) {
            Enumeration it = (Enumeration) object;
            while (it.hasMoreElements()) {
                index--;
                if (index == -1) {
                    return it.nextElement();
                } else {
                    it.nextElement();
                }
            }
            throw new IndexOutOfBoundsException("Entry does not exist: " + index);
        } else {
            try {
                return Array.get(object, index);
            } catch (IllegalArgumentException ex) {

View on GitHub (pinned to 7b4caf9e54)

Solutions

Bound the index against the known size before calling get (index < size).
For positional access prefer a List (uses List.get directly) over a Map/Iterator.
Do not reuse a one-shot Iterator across multiple get() calls; obtain a fresh iterator each time.
For Map access, use the key directly instead of a positional index.

Example fix

// before
Object v = CollectionUtils.get(map, map.size()); // Entry does not exist

// after
Object v = CollectionUtils.get(map, map.size() - 1); // last valid index

Defensive patterns

Strategy: validation

Validate before calling

int size = CollectionUtils.size(object);
if (index >= 0 && index < size) {
    Object v = CollectionUtils.get(object, index);
} else {
    // index past the end of an iterator-backed collection
}

Try / catch

try {
    v = CollectionUtils.get(object, index);
} catch (IndexOutOfBoundsException e) {
    v = null; // iterator exhausted before index
}

Prevention

Bound the index against size() before calling get on Map/Collection/Iterator.
Prefer List.get for positional access; reserve get() for genuinely unknown types.
Never reuse a one-shot Iterator across multiple get() calls.

When it happens

Trigger: Calling get on a Map/Collection/Iterator with an index >= the number of available elements; iterating a one-shot Iterator that had already been partially consumed before the call.

Common situations: Assuming a Map's position matches insertion order without an ordered map; requesting an index larger than size(); reusing a Stream/Iterator that has already advanced; off-by-one when index equals size().

Related errors

AI-assisted analysis of Blankj/AndroidUtilCode@7b4caf9e54 (2026-08-14). Data as JSON: /api/errors/f1186414bc5f77b9. Report an issue: GitHub.