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
时间： 2024-08-23 23:36:55