java如何导入/报告：jackrabbit中的安全性？

Question

当我使用importXML从xml文件导入rep:security时，发生了一个错误。 我找不到解决办法。[我用exportSystemView导出rep:security]

InputStream input = new FileInputStream("d:\\bk.xml");
session.importXML("/", input, ImportUUIDBehavior.IMPORT_UUID_COLLISION_REPLACE_EXISTING);
            input.close();
session.save();

工作区的配置：

<?xml version="1.0" encoding="UTF-8"?>
<Workspace name="security">
        <FileSystem class="org.apache.jackrabbit.core.fs.local.LocalFileSystem">
            <param name="path" value="${wsp.home}"/>
        </FileSystem>
        <PersistenceManager class="org.apache.jackrabbit.core.persistence.db.DerbyPersistenceManager">
          <param name="url" value="jdbc:derby:${wsp.home}/db;create=true"/>
          <param name="schemaObjectPrefix" value="${wsp.name}_"/>
          <param name="shutdownOnClose" value="false"/>
        </PersistenceManager>
        <SearchIndex class="org.apache.jackrabbit.core.query.lucene.SearchIndex">
            <param name="path" value="${wsp.home}/index"/>
            <param name="supportHighlighting" value="true"/>
        </SearchIndex>
        <Import>
            <ProtectedNodeImporter class="org.apache.jackrabbit.core.xml.AccessControlImporter"/>
            <ProtectedItemImporter class="org.apache.jackrabbit.core.security.user.UserImporter">
                <param name="importBehavior" value="besteffort"/>
            </ProtectedItemImporter>
        </Import>
</Workspace>

将引发以下异常：

javax.jcr.nodetype.ConstraintViolationException: /rep:security/rep:authorizables
/rep:groups/U/Us/UserAdmin: mandatory property {internal}principalName does not
exist
        at org.apache.jackrabbit.core.ItemImpl.validateTransientItems(ItemImpl.j
ava:464)
        at org.apache.jackrabbit.core.ItemImpl.save(ItemImpl.java:1097)
        at org.apache.jackrabbit.core.SessionImpl.save(SessionImpl.java:920).... 

我找不到答案，有人知道答案吗？ 提前谢谢