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原 Java学习之Xml系列二:xml按条件查询、xml递归遍历所有元素和属性

时间:2014-07-23 17:38:01      阅读:445      评论:0      收藏:0      [点我收藏+]

xml中加入了几条,为了方便查询时作为示例。

话不多说见代码注释:

DTD文件:SwordTypeDefinition.dtd

<?xml version="1.0" encoding="UTF-8"?>
<!ELEMENT SwordLibrary (Sword*)>
<!ELEMENT Sword (SwordName,Price,Attack)>
<!ELEMENT SwordName (#PCDATA)>
<!ELEMENT Price (#PCDATA)>
<!ELEMENT Attack (#PCDATA)>
<!ATTLIST Sword sno CDATA #REQUIRED>
<!ATTLIST Price type CDATA #IMPLIED>
<!ATTLIST Attack factor CDATA "1.0">

XML文件:SwordLib.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE SwordLibrary SYSTEM "SwordTypeDefinition.dtd">
<SwordLibrary>
<Sword sno=‘s1‘>
<SwordName>欢欣之刃</SwordName>
<Price>1000</Price>
<Attack>10</Attack>
</Sword>
<Sword sno=‘s2‘>
<SwordName>夜叉</SwordName>
<Price>2050</Price>
<Attack factor="2.0">30</Attack>
</Sword>
<Sword sno=‘s3‘>
<SwordName>魔棒</SwordName>
<Price type="Dollar">200</Price>
<Attack>0</Attack>
</Sword>
</SwordLibrary>

java代码:

package JavaLeaner.XmlTest;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class XmlDemo2 {

    /*
     * 按照属性sno查询
     */
    @Test
    public void Test1() throws IOException, ParserConfigurationException, SAXException 
    {
        System.out.println("请输入查找的sword的sno:");
        //这里是java 的控制台输入方法,老忘记,TT
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        String sno=br.readLine();
        Element st= FindSwordBySno(sno);
        if (st != null) {
            String sname = st.getElementsByTagName("SwordName").item(0).getTextContent();
            System.out.println("此剑为:" + sname);
        }
        else
        {
            System.out.println("这里不卖!!" );
        }
        
/*        请输入查找的sword的sno:
        s2
        此剑为:夜叉
        */
    }
    
    Element FindSwordBySno(String sno)throws ParserConfigurationException, SAXException, IOException
    {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docDuilder = factory.newDocumentBuilder();
        Document doc = docDuilder.parse("src/JavaLeaner/XmlTest/SwordLib.xml");
        NodeList list = doc.getElementsByTagName("Sword");
        for(int i=0;i<list.getLength();i++)
        {
            Element swordTag=(Element)list.item(i);
            String snoText=swordTag.getAttribute("sno");
            if(snoText.equals(sno))
            {
                return swordTag;
            }
        }
        return null;
    }
    
    
    /*
     * 递归遍历整个xml文档的元素和属性
     */
    @Test
    public void Test2() throws IOException, ParserConfigurationException, SAXException 
    {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docDuilder = factory.newDocumentBuilder();
        Document doc = docDuilder.parse("src/JavaLeaner/XmlTest/SwordLib.xml");
        //取文档根元素
        Element rootElement= doc.getDocumentElement();
        String rootName = rootElement.getTagName();
        System.out.println(rootName);
        DeepIn(rootElement);
        

    }
    
    void DeepIn(Element parentElement)
    {
        NodeList list=parentElement.getChildNodes();
        for(int i=0;i<list.getLength();i++)
        {
            if (list.item(i) instanceof Element) {
                Element nodeElement = (Element) list.item(i);
                String eName = nodeElement.getNodeName();
                System.out.println(eName);
                NamedNodeMap nnm=nodeElement.getAttributes();
                //注意:NamedNodeMap也不支持java.lang.Iterable,所以不能增强佛如循环
                for(int j=0;j<nnm.getLength();j++)
                {
                    String aName = nnm.item(j).getNodeName();
                    String aText = nnm.item(j).getTextContent();
                    System.out.println("    "+aName+"="+aText);
                }
                DeepIn(nodeElement);
            }
            else
            {
                //System.out.println("not Element:"+list.item(i).getTextContent()+"------");
/*                注意: getChildNodes()获取的不仅仅包括子元素,还包括其他的字符串等文本,这里之所以会出现这些not Element:-----,是因为xml文件中有许多空白符和换行的缘故
 *                 在实际使用中,可以像本例一样用instanceof Element的条件判断将这些东西过滤掉。
 *                 这个结果不包含属性部分的代码:
 *                 SwordLibrary
                not Element:
                ------
                Sword
                not Element:
                ------
                SwordName
                not Element:欢欣之刃------
                not Element:
                ------
                Price
                not Element:1000------
                not Element:
                ------
                Attack
                not Element:10------
                not Element:
                ------
                not Element:
                ------
                Sword
                not Element:
                ------
                SwordName
                not Element:夜叉------
                not Element:
                ------
                Price
                not Element:2050------
                not Element:
                ------
                Attack
                not Element:30------
                not Element:
                ------
                not Element:
                ------
                Sword
                not Element:
                ------
                SwordName
                not Element:魔棒------
                not Element:
                ------
                Price
                not Element:200------
                not Element:
                ------
                Attack
                not Element:0------
                not Element:
                ------
                not Element:
                ------*/

            }
    
        }
/*        结果:
 * 
 *         SwordLibrary
        Sword
            sno=s1
        SwordName
        Price
        Attack
            factor=1.0
        Sword
            sno=s2
        SwordName
        Price
        Attack
            factor=2.0
        Sword
            sno=s3
        SwordName
        Price
            type=Dollar
        Attack
            factor=1.0*/

    }
    
    
    
}


原 Java学习之Xml系列二:xml按条件查询、xml递归遍历所有元素和属性,布布扣,bubuko.com

原 Java学习之Xml系列二:xml按条件查询、xml递归遍历所有元素和属性

原文:http://my.oschina.net/u/1156339/blog/294170

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