XPath can't find an engine

Question

I inherited some code that is using XPath for which I am a novice. I have it now so that it loads the document, but when the document.selectPath(queryPath) it always fails with the following error:

java.lang.RuntimeException:  Trying XBeans path engine... Trying XQRL... Trying delegated path engine... FAILED on //
        at org.apache.xmlbeans.impl.store.Path.getCompiledPath(Path.java:173)
        at org.apache.xmlbeans.impl.store.Path.getCompiledPath(Path.java:130)
        at org.apache.xmlbeans.impl.store.Cursor._selectPath(Cursor.java:902)
        at org.apache.xmlbeans.impl.store.Cursor.selectPath(Cursor.java:2634)
        at org.apache.xmlbeans.impl.values.XmlObjectBase.selectPath(XmlObjectBase.java:462)
        at org.apache.xmlbeans.impl.values.XmlObjectBase.selectPath(XmlObjectBase.java:446)

Answer 1

Thank you jor for the post. I was confused as earlier commands to xml beans were successful.

Without saxon, this still works:

MapDocument doc;
...
String cityQuery = "$this//City";
XmlObject[] cities = doc.selectPath(cityQuery);

However saxon is required for explicit selection of fields within tags:

String aveQuery= "$this//Street[Kind='Avenue']";
XmlObject[] avenues = doc.selectPath(aveQuery); // RuntimeException without saxon on path

java.lang.RuntimeException:
Trying XBeans path engine... Trying XQRL... Trying delegated path engine... FAILED on $this//Street[Kind='Avenue']

I hope this might be of use to others that encounter a similar issue.

Answer 2

如果您在xpath中有[]的动作，则它正在搜索外部xpath引擎。.您必须下载saxonb9-0-0-4j＆xmlbeans-xpath-2.4.0.jar并将其添加到类路径中

Answer 3

您需要在类路径中使用一个XPath引擎，该引擎依赖于XMLBeans版本，请参见http://wiki.apache.org/xmlbeans/XmlBeansFaq#whatJars

Answer 4

worked for me:

 <dependency> <groupId>org.apache.xmlbeans</groupId> <artifactId>xmlbeans</artifactId> <version>4.0.0</version> </dependency> <dependency> <groupId.net.sf.saxon</groupId> <artifactId>Saxon-HE</artifactId> <version>10.6</version> </dependency> <dependency> <groupId>org.dom4j</groupId> <artifactId>dom4j</artifactId> <version>2.1.3</version> </dependency>