spring-projects/spring-framework · error · IllegalArgumentException

'targetMapClass' must not be null

Error message

'targetMapClass' must not be null

What it means

Error "'targetMapClass' must not be null" thrown in spring-projects/spring-framework.

Source

Thrown at spring-beans/src/main/java/org/springframework/beans/factory/config/MapFactoryBean.java:61

	/**
	 * Set the source Map, typically populated via XML "map" elements.
	 */
	public void setSourceMap(Map<?, ?> sourceMap) {
		this.sourceMap = sourceMap;
	}

	/**
	 * Set the class to use for the target Map. Can be populated with a fully
	 * qualified class name when defined in a Spring application context.
	 * <p>Default is a linked HashMap, keeping the registration order.
	 * @see java.util.LinkedHashMap
	 */
	@SuppressWarnings("rawtypes")
	public void setTargetMapClass(@Nullable Class<? extends Map> targetMapClass) {
		if (targetMapClass == null) {
			throw new IllegalArgumentException("'targetMapClass' must not be null");
		}
		if (!Map.class.isAssignableFrom(targetMapClass)) {
			throw new IllegalArgumentException("'targetMapClass' must implement [java.util.Map]");
		}
		this.targetMapClass = targetMapClass;
	}


	@Override
	@SuppressWarnings("rawtypes")
	public Class<Map> getObjectType() {
		return Map.class;
	}

	@Override
	@SuppressWarnings("unchecked")
	protected Map<Object, Object> createInstance() {
		if (this.sourceMap == null) {

View on GitHub (pinned to e8729d0438)

When it happens

Trigger: Thrown at spring-beans/src/main/java/org/springframework/beans/factory/config/MapFactoryBean.java:61 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of spring-projects/spring-framework@e8729d0438 (2026-08-04). Data as JSON: /data/errors/317ec6ed7dc64d5d.json. Report an issue: GitHub.