StaxWriter.java 文件源码

/**
 * Adds a namespace mapping for [name] to [namespaces], if it doesn't already exist on [writer].
 */
private static boolean register(XMLEventWriter writer, List<Namespace> namespaces, QName name) {
    String nsUri = name.getNamespaceURI();
    if (nsUri != null && !nsUri.isEmpty()) {
        String existing = writer.getNamespaceContext().getNamespaceURI(name.getPrefix());
        Namespace ns = evtFactory.createNamespace(name.getPrefix(), nsUri);
        if ((existing == null || !existing.equals(nsUri)) && !namespaces.stream().anyMatch(n ->
            n.getPrefix().equals(ns.getPrefix())
        )) {
            namespaces.add(ns);
            return true;
        }
    }
    return false;
}