java Xpath 小例

java

package  test;

import  java.io.StringWriter;

import  javax.xml.parsers.DocumentBuilder;
import  javax.xml.parsers.DocumentBuilderFactory;
import  javax.xml.transform.TransformerFactory;
import  javax.xml.transform.dom.DOMSource;
import  javax.xml.transform.stream.StreamResult;
import  javax.xml.xpath.XPath;
import  javax.xml.xpath.XPathExpression;
import  javax.xml.xpath.XPathFactory;

import  org.w3c.dom.Document;
import  org.w3c.dom.Element;

import  com.opensymphony.xwork2.ActionSupport;

public   class  TAction  extends  ActionSupport {
     private  String xml1;
     public  String getXml1() {
         return  xml1;
    }
     public   void  setXml1(String xml1) {
         this .xml1  =  xml1;
    }
    {
        
         try  {
            DocumentBuilderFactory factory  =  DocumentBuilderFactory
                    .newInstance();
            DocumentBuilder builder  =  factory.newDocumentBuilder();

             //  创建
            Document document  =  builder.newDocument();
            Element root  =  document.createElement( " root " );
            document.appendChild(root);
            Element name  =  document.createElement( " name " );
            name.setAttribute( " type " ,  " ok " );
            name.appendChild(document.createTextNode( " liu!k>a^i!@$^*><{}yi " ));
            root.appendChild(name);

             //  从数据库提取
             //  String xmlstr= "<beans><name>liu</name><pass>123</pass></beans>";
             //  builder.parse(new ByteArrayInputStream(str.getBytes()));

             //  save to mysql
            StringWriter output  =   new  StringWriter();
            TransformerFactory.newInstance().newTransformer().transform(
                     new  DOMSource(document),  new  StreamResult(output));
             // System.out.println(output.toString());

             //  对内展现
            XPathFactory factoryXpah  =  XPathFactory.newInstance();
            XPath xpath  =  factoryXpah.newXPath();
            XPathExpression expr  =  xpath.compile( " //name " );
            System.out.println(expr.evaluate(document));
            expr  =  xpath.compile( " //name/@type " );
             // System.out.println(expr.evaluate(document));

             //  对jsp jstl xml
             //  参考  http://www.java2s.com/Code/Java/JSP/XML.htm

             this .xml1  =  output.toString().replaceAll( " <\\?.*\\?> " ,  "" );
        }  catch  (Exception e) {
            e.printStackTrace();
        }
    }
     public   static   void  main(String[] args) {
        System.out.println( new  TAction().getXml1());
    }
    

}

jsp

<% @ page language = " java "  contentType = " text/html; charset=UTF-8 "  pageEncoding = " UTF-8 " %>
<% @taglib uri = " http://java.sun.com/jstl/xml_rt "  prefix = " x " %>
<% @taglib uri = " http://java.sun.com/jstl/core_rt "  prefix = " c " %>
< html >
< head >
< meta  http-equiv ="Content-Type"  content ="text/html; charset=UTF-8" >
</ head >
< body >
     < c:import  url ="http://127.0.0.1:38080/ljw_svn2/test/data.do"  var ="webXml"   />
     < x:parse  xml ="${webXml}"  var ="doc"   />
      < x:out  select ="$doc//name" />< br  />
</ body >
</ html >

<% @ page language = " java "  contentType = " text/html; charset=UTF-8 "  pageEncoding = " UTF-8 " %>
<% @taglib uri = " http://java.sun.com/jstl/xml_rt "  prefix = " x " %>
<% @taglib uri = " http://java.sun.com/jstl/core_rt "  prefix = " c " %>
< html >
< head >
< meta  http-equiv ="Content-Type"  content ="text/html; charset=UTF-8" >
</ head >
< body >

     < c:set  var ="basepath"  value ="<%=request.getScheme() + " ://" + request.getServerName() + ":" + request.getServerPort() + request.getContextPath() + "/" % > "> </ c:set >
     < c:import  url ="${basepath}/infoPublishing.do?c=showXmlData&bid=63"  var ="webXml"   />
     < x:parse  xml ="${webXml}"  var ="doc"   />
     类型： < x:out  select ="$doc//typeFlag" />< br  />
     qq： < x:out  select ="$doc//qq" />< br  />
     msn： < x:out  select ="$doc//msn" />< br  />


</ body >
</ html >