java中的四种XML读取操作

1.java自带的DOM解析.

import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

import org.xml.sax.InputSource;

public class ReaderXmlForDOM {

public static void main(String args[]) {

String text ="<XML><A>123</A><B>whl123</B><C>亮亮</C><D>1</D><E>1</E><F>165074</F><G>贫穷</G><H>1698.0</H><I>初级士官</I><J>湖南</J><K>常德</K><L>1</L></XML>"

long begin = System.currentTimeMillis();

parse( text );

long after = System.currentTimeMillis();

System.out.println("DOM用时"+(after-begin)+"毫秒");

}

public static void parse(String protocolXML) {

try {

DocumentBuilderFactory factory = DocumentBuilderFactory

.newInstance();

DocumentBuilder builder = factory.newDocumentBuilder();

Document doc = builder

.parse(new InputSource(new StringReader(protocolXML)));

Element root = doc.getDocumentElement();

NodeList books = root.getChildNodes();

if (books != null) {

for (int i = 0; i < books.getLength(); i++) {

Node book = books.item(i);

System.out.println("节点=" + book.getNodeName() + "/ttext="

+ book.getFirstChild().getNodeValue());

}

}

} catch (Exception e) {

e.printStackTrace();

}

}

}

我当时dom解析用时是个不稳定的值在62-78毫秒之间.

以下的三种方法mian方法里面都是一样的解析那段字符串,记录用时,就不在贴出, 只贴出所用的解析部分

2.java自带的SAX解析.

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.DefaultHandler;

public class ReaderXmlForSAX {

public static void parse(String protocolXML) {

try {

SAXParserFactory saxfac = SAXParserFactory.newInstance();

SAXParser saxparser = saxfac.newSAXParser();

TestSAX tsax = new TestSAX();

saxparser.parse(new InputSource(new StringReader(protocolXML)),tsax);

} catch (Exception e) {

e.printStackTrace();

}

}

}

class TestSAX extends DefaultHandler{

private StringBuffer buf;

private String str;

public TestSAX(){

super();

}

public void startDocument() throws SAXException{

buf=new StringBuffer();

System.out.println("*******开始解析XML*******");

}

public void endDocument() throws SAXException{

System.out.println("*******XML解析结束*******");

}

public void endElement(String namespaceURI,String localName,String fullName )throws SAXException{

str = buf.toString();

System.out.println("节点="+fullName+"/tvalue="+buf+" 长度="+buf.length());

System.out.println();

buf.delete(0,buf.length());

}

public void characters( char[] chars, int start, int length )throws SAXException{

//将元素内容累加到StringBuffer中

buf.append(chars,start,length);

}

}

SAX用时是62毫秒,最快的.但是需要多写一个类

3.DOM4J解析,需要下载对应的jar包

import java.util.Iterator;

import java.util.List;

import org.dom4j.Document;

import org.dom4j.DocumentHelper;

import org.dom4j.Element;

public class ReaderXmlForDOM4J {

//DOM4j解析XML

public static void parse(String protocolXML) {

try {

Document doc=(Document)DocumentHelper.parseText(protocolXML);

Element books = doc.getRootElement();

System.out.println("根节点"+books.getName());

// Iterator users_subElements = books.elementIterator("UID");//指定获取那个元素

Iterator Elements = books.elementIterator();

while(Elements.hasNext()){

Element user = (Element)Elements.next();

System.out.println("节点"+user.getName()+"/ttext="+user.getText());

List subElements = user.elements();

// List user_subElements = user.elements("username");指定获取那个元素

// System.out.println("size=="+subElements.size());

// for( int i=0;i<subElements.size();i++){

// Element ele = (Element)subElements.get(i);

// System.out.print(ele.getName()+" : "+ele.getText()+" ");

// }

System.out.println();

}

} catch (Exception e) {

e.printStackTrace();

}

}

}

DOM4J的用时为140毫秒,慢 并且还需要单独的jar包

4.JDOM解析,需要下载对应的jar包

import java.io.StringReader;

import java.util.List;

import org.jdom.Document;

import org.jdom.Element;

import org.jdom.input.SAXBuilder;

import org.xml.sax.InputSource;

public class ReaderXmlForJDOM {

public static void parse(String protocolXML) {

SAXBuilder builder=new SAXBuilder(false);

try {

Document doc = builder.build(new InputSource(new StringReader(protocolXML)));

Element eles = doc.getRootElement(); // 得到根元素

System.out.println("根节点"+eles.getName());

List<Element> list = eles.getChildren(); // 得到元素的集合

//List studentList = students.getChildren("student"); // 得到指定元素（节点）的集合

if( list!=null){

for (int i = 0; i < list.size(); i++) {

Element book = (Element)list.get(i);

System.out.println("节点=" + book.getName() + "/ttext="

+ book.getValue());

}

}

} catch (Exception e) {

e.printStackTrace();

}

}

}

JDOM的用时为125毫秒,比较慢 并且还需要单独的jar包