Java com.ximpleware parse XML-XPath-Syntax错误在==>；

我使用com.ximpleware并尝试解析如下XML：

<S2SCTScf:SCTScfBlkCredTrf xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:S2SCTScf="urn:S2SCTScf:xsd:$SCTScfBlkCredTrf" xsi:schemaLocation="urn:S2SCTScf:xsd:$SCTScfBlkCredTrf file:///T:/CommonData%201/CBS/CBS%20Payments%20Team/Testing/XSD/SCT/SCTScfBlkCredTrf.xsd">
        <CdtTrfTxInf>
            <PmtId>
                <EndToEndId>171766 12856615</EndToEndId>
                <TxId>6022064LAS99</TxId>
            </PmtId>
        ..............
        </CdtTrfTxInf>
        ..............
</S2SCTScf:SCTScfBlkCredTrf>

向我抛出一个错误：

 Syntax error after or around the end of ==>
 Exception during navigation com.ximpleware.XPathParseException: No URL found for prefix:S2SCTScf

如果不能修改我的XML，你知道我应该做什么吗？

---

谢谢

不熟悉vtd xml，但文档建议在

selectXPath（）

中使用名称空间前缀之前，需要先通过注册名称空间前缀：

 Syntax error after or around the end of ==>
 Exception during navigation com.ximpleware.XPathParseException: No URL found for prefix:S2SCTScf

.....
ap.declareXPathNameSpace("S2SCTScf", "urn:S2SCTScf:xsd:$SCTScfBlkCredTrf");
str = "/S2SCTScf:SCTScfBlkCredTrf/CdtTrfTxInf";
ap.selectXPath(str);
.....