如何动态地指一个XML文件XQuery中撒克逊

Question

我使用XQuery处理器撒克逊人，现在我们写的Xquery在“.xqy”文件，其中我们指上，我们将执行Xquery.please看到例如XML文件如下─

for $x in doc("books.xml")/books/book 
where $x/price>30 
return $x/title 

现在我想使用没有存储在一些path.Say比如我想引用下面的XML作为字符串动态生成的XML，该怎么做？
String book= <books> <book category="JAVA"> <title lang="en">Learn Java in 24 Hours</title> <author>Robert</author> <year>2005</year> <price>30.00</price> </book> <book category="DOTNET"> <title lang="en">Learn .Net in 24 hours</title> <author>Peter</author> <year>2011</year> <price>40.50</price> </book> <book category="XML"> <title lang="en">Learn XQuery in 24 hours</title> <author>Robert</author> <author>Peter</author> <year>2013</year> <price>50.00</price> </book> <book category="XML"> <title lang="en">Learn XPath in 24 hours</title> <author>Jay Ban</author> <year>2010</year> <price>16.50</price> </book> </books>

的Java代码 -

`

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.InputStream; 

import javax.xml.xquery.XQConnection; 
import javax.xml.xquery.XQDataSource; 
import javax.xml.xquery.XQException; 
import javax.xml.xquery.XQPreparedExpression; 
import javax.xml.xquery.XQResultSequence; 

import com.saxonica.xqj.SaxonXQDataSource; 

public class XQueryTester { 
    public static void main(String[] args){ 
     try { 
     execute(); 
     } catch (FileNotFoundException e) { 
     e.printStackTrace(); 
     } catch (XQException e) { 
     e.printStackTrace(); 
     } 
    } 

    private static void execute() throws FileNotFoundException, XQException{ 
     InputStream inputStream = new FileInputStream(new File("books.xqy")); 
     XQDataSource ds = new SaxonXQDataSource(); 
     XQConnection conn = ds.getConnection(); 
     XQPreparedExpression exp = conn.prepareExpression(inputStream); 
     XQResultSequence result = exp.executeQuery(); 
     while (result.next()) { 
     System.out.println(result.getItemAsString(null)); 
     } 
    }  
} 

`

Answer 1

如果你寻找到输入绑定的方式使用Java查询（在上下文项）我建议使用Saxon的S9API（Java中用于处理XSLT，XPath和XQuery的最直观的API）。

这里是如何实例撒克逊，编译查询，分析输入和评估与约束为上下文项的输入文档的查询：

// the Saxon processor object 
Processor saxon = new Processor(false); 

// compile the query 
XQueryCompiler compiler = saxon.newXQueryCompiler(); 
XQueryExecutable exec = compiler.compile(new File("yours.xqy")); 

// parse the string as a document node 
DocumentBuilder builder = saxon.newDocumentBuilder(); 
String input = "<xml>...</xml>"; 
Source src = new StreamSource(new StringReader(input)); 
XdmNode doc = builder.build(src); 

// instantiate the query, bind the input and evaluate 
XQueryEvaluator query = exec.load(); 
query.setContextItem(doc); 
XdmValue result = query.evaluate(); 

注意，如果Java代码生成XML文档，我强烈建议您使用S9API直接在内存中构建树，而不是将该XML文档生成为字符串，然后对其进行解析。如果可能的话。

Answer 2

这里是我是如何实现由以上所建议的用户自

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.StringReader; 

import javax.xml.transform.Source; 
import javax.xml.transform.stream.StreamSource; 
import javax.xml.xquery.XQConnection; 
import javax.xml.xquery.XQDataSource; 
import javax.xml.xquery.XQException; 
import javax.xml.xquery.XQPreparedExpression; 
import javax.xml.xquery.XQResultSequence; 

import net.sf.saxon.s9api.DocumentBuilder; 
import net.sf.saxon.s9api.Processor; 
import net.sf.saxon.s9api.SaxonApiException; 
import net.sf.saxon.s9api.XQueryCompiler; 
import net.sf.saxon.s9api.XQueryEvaluator; 
import net.sf.saxon.s9api.XQueryExecutable; 
import net.sf.saxon.s9api.XdmNode; 
import net.sf.saxon.s9api.XdmValue; 

import com.saxonica.xqj.SaxonXQDataSource; 


public class Xml { public static void main(String[] args){ 
    try { 
     process(); 
    } catch (FileNotFoundException e) { 
     e.printStackTrace(); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
    } 
public static void process() throws SaxonApiException, IOException{ 
    // the Saxon processor object 
    Processor saxon = new Processor(false); 

    // compile the query 
    XQueryCompiler compiler = saxon.newXQueryCompiler(); 
    XQueryExecutable exec; 
    exec = compiler.compile(new File("E:\\abc.xqy")); 


    // parse the string as a document node 
    DocumentBuilder builder = saxon.newDocumentBuilder(); 
    String input = "<data><employee id=\"1\"><name>A</name>" 
     + "<title>Manager</title></employee>+<employee id=\"2\"><name>B</name>" 
     + "<title>Manager</title></employee>+</data>"; 
    Source src = new StreamSource(new StringReader(input)); 
    XdmNode doc = builder.build(src); 

    // instantiate the query, bind the input and evaluate 
    XQueryEvaluator query = exec.load(); 
    query.setContextItem(doc); 
    XdmValue result = query.evaluate(); 
    System.out.println(result.itemAt(0)); 
}