[4.4.x] Remove static ThreadLocal caching in XmlUtils to prevent ClassLoader leaks#2532
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jbonofre merged 1 commit intoApr 15, 2026
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…leaks The static ThreadLocal fields holding DocumentBuilderFactory, TransformerFactory and SAXParserFactory pin the ClassLoader of the XML provider bundle on long-lived Karaf worker threads. When that bundle is updated or refreshed, the old ClassLoader can never be GC'd, leading to zombie bundles and Metaspace growth. Create fresh factory instances per call instead of caching them. The public API is unchanged. Fixes apache#2278
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Backport of #2516 to
karaf-4.4.x.The static
ThreadLocalfields holdingDocumentBuilderFactory,TransformerFactoryandSAXParserFactorypin the ClassLoader of the XML provider bundle on long-lived Karaf worker threads. When that bundle is updated or refreshed, the old ClassLoader can never be GC'd, causing zombie bundles and Metaspace growth.This patch removes the
ThreadLocalcaching and creates fresh factory instances per call. The public API is unchanged.Fixes #2278