This is the XML Schema for the Handler chain configuration descriptor. The configuration file must be in the classpath within the JAR/WAR file. All Handler chain configuration descriptors should indicate the descriptor schema by using the Jakarta EE namespace: https://jakarta.ee/xml/ns/jakartaee and by indicating the version of the schema by using the version element as shown below: ... The instance documents may indicate the published version of the schema using the xsi:schemaLocation attribute for Jakarta EE namespace with the following location: https://jakarta.ee/xml/ns/jakartaee/jakartaee_web_services_metadata_handler_3_0.xsd The handler-chains element is the root element for defining handlerchains. The Jakarta Web Services Metadata specification defines the @jakarta.jws.HandlerChain annotation that refers to an XML descriptor conforming to this schema.