<?xml version="1.0" encoding="gb2312"?>
<books>
    <book id="1">
        <name>goodbook</name>
        <price>200.20</price>
    </book>
    <book id="2">
        <name>badbook</name>
        <price>100.10</price>
    </book>
</books>

另有查询文件query.txt

let $book:=//book
where $book/@id<=1
return
 <books>
 {
  $book
 }
 </books>

java文件testxqengine.java

import com.fatdog.xmlEngine.XQEngine;
import com.fatdog.xmlEngine.ResultList;
import org.xml.sax.helpers.XMLReaderFactory;

import java.io.PrintWriter;

public class testxqengine {
    public static void main(String[] args)
    {
        XQEngine myengine= new XQEngine();
        try
        {
            myengine.setXMLReader(XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser"));  //用的xerces解析器
            myengine.setDocument("d:/java-procs/xmltest/data/books.xml");
            ResultList rl=myengine.setQueryFromFile("d:/java-procs/xmltest/data/query.txt");  //这里暂用绝对路径做试验
            System.out.println(rl.emitXml(true)); //这个true是让输出的xml符合一般格式的
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}

程序输出结果：

<books><book id="1">
        <name>goodbook</name>
        <price>200.20</price>
    </book>
<book id="2">
        <name>badbook</name>
        <price>100.10</price>
    </book>
</books>

这里只是给出了一个最简单的例子，复杂点的应用请查询api文档和xquery语法

顺便问一下，怎么发的帖子和回帖都没有发布时间啊，难道是我没看见