spring-projects/spring-framework · error · InvalidPropertyException

Invalid list index in property path '{tokens.canonicalName}'

Error message

Invalid list index in property path '{tokens.canonicalName}'

What it means

Thrown in the List branch of processKeyedProperty when the index is in range that does not trigger auto-grow (index < size expected) and list.set(index, convertedValue) throws IndexOutOfBoundsException. Spring rewraps it as InvalidPropertyException 'Invalid list index'. This is the non-auto-grow / contiguous-range failure for indexed List writes.

Source

Thrown at spring-beans/src/main/java/org/springframework/beans/AbstractNestablePropertyAccessor.java:329

				for (int i = size; i < index; i++) {
					try {
						list.add(null);
					}
					catch (NullPointerException ex) {
						throw new InvalidPropertyException(getRootClass(), this.nestedPath + tokens.canonicalName,
								"Cannot set element with index " + index + " in List of size " +
								size + ", accessed using property path '" + tokens.canonicalName +
								"': List does not support filling up gaps with null elements");
					}
				}
				list.add(convertedValue);
			}
			else {
				try {
					list.set(index, convertedValue);
				}
				catch (IndexOutOfBoundsException ex) {
					throw new InvalidPropertyException(getRootClass(), this.nestedPath + tokens.canonicalName,
							"Invalid list index in property path '" + tokens.canonicalName + "'", ex);
				}
			}
		}

		else if (propValue instanceof Map map) {
			TypeDescriptor mapKeyType = ph.getMapKeyType(tokens.keys.length);
			TypeDescriptor mapValueType = ph.getMapValueType(tokens.keys.length);
			// IMPORTANT: Do not pass full property name in here - property editors
			// must not kick in for map keys but rather only for map values.
			Object convertedMapKey = convertIfNecessary(null, null, lastKey,
					mapKeyType.getResolvableType().resolve(), mapKeyType);
			Object oldValue = null;
			if (isExtractOldValueForEditor()) {
				oldValue = map.get(convertedMapKey);
			}
			// Pass full property name and old value in here, since we want full
			// conversion ability for map values.

View on GitHub (pinned to e8729d0438)

Solutions

1. Enable wrapper.setAutoGrowNestedPaths(true) so the list grows up to the auto-grow limit.
2. Pre-fill the list so the target index already exists before binding.
3. Use contiguous indices starting at 0 when binding sequentially.
4. Switch to add-style binding via a non-indexed property if order is not significant.

Example fix

// before
List<Item> items = new ArrayList<>(); // size 0
wrapper.setPropertyValue("items[2]", item); // autoGrow off -> OOB

// after
wrapper.setAutoGrowNestedPaths(true);
wrapper.setPropertyValue("items[2]", item);

int idx = 7;
List<Object> list = (List<Object>) wrapper.getPropertyValue("items");
if (list == null) { list = new ArrayList<>(); wrapper.setPropertyValue("items", list); }
while (list.size() <= idx) list.add(null);
wrapper.setPropertyValue("items[" + idx + "]", item);

static boolean indexExistsOrGrow(List<?> list, BeanWrapper bw, int idx) {
    return idx < list.size() || (bw.isAutoGrowNestedPaths() && idx < bw.getAutoGrowCollectionLimit());
}

try { wrapper.setPropertyValue("items[" + idx + "]", item); }
catch (InvalidPropertyException ex) { /* pre-fill list then retry */ }

When it happens

Trigger: setProperty("items[7]", x) on an ArrayList of size 3 with autoGrowNestedPaths=false; index beyond the list size but auto-grow off; binding to a list that was not pre-sized.

Common situations: autoGrowNestedPaths disabled by default in custom BeanWrapper usage; binding positional data into a List without pre-filling; converting from array semantics where auto-grow was expected but not enabled.

Related errors

• Invalid array index in property path '{tokens.canonicalName}
• Cannot set element with index {index} in List of size {size}
• Cannot get element with index {index} from Collection of siz
• Cannot get element with index {index} from Iterable of size
• Index of out of bounds in property path '${propertyName}'

AI-assisted analysis of spring-projects/spring-framework@e8729d0438 (2026-08-04). Data as JSON: /data/errors/b2d3c4ecf5852483.json. Report an issue: GitHub.