xml的解析

1：方法一
/*****
	 * 解析xml文件
	 * @param filename 要解析的xml文件
	 */
	private void parsesXML(String filename){
		try {
			//通过  SAXBuilder 对象去 解析一个 xml 文件，获取 Document 对象
			SAXBuilder  saxBuilder  = new SAXBuilder();
			//获取到的 Document 对象中封装了所有xml文档内容
			InputStream in = getClass().getResourceAsStream(filename);
			Document document = saxBuilder.build(in);
			
			//得到根节点
			Element root = document.getRootElement();		//DataSource	
			System.out.println("root:"+root.getName());
			
			//得到根节点下面的所有子节点
			List<Element> children = root.getChildren(); //param
			
			//循环遍历所有子节点
			for (Element element : children) {
				//获取属性
				List<Attribute> attributes = element.getAttributes(); //database  version 
				for (Attribute attribute : attributes) {
					System.out.println(attribute.getName()+":"+attribute.getValue());
				}
				
				//获得属性下面的 ‘集合’ <driver> <url> <users> <password> 
				List<Element> childs = element.getChildren();
				
				for (Element child : childs) {
					System.out.println(child.getName()+":"+child.getValue());
				}
				
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}


2.方法二
/**
 * XML 字符串的高效简单解析
 * XML高效解析方法对比，主要包括indexOf，contains，startsWith和jdom和sax解析一个XML字符串的时间开销对比。
 * 昨天发的一篇文章，得到大家的拍砖，
 * 为了编写高效的系统。特发此文。
 * @author [e-mail]
 * @right ALL right SINA and Under by GPL
 */
import java.io.IOException;
import java.io.StringReader;
import java.util.List;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.xml.sax.InputSource;

public class strXML {

	public static  String[] parseString() {
		String[] sinaPayArr = new String[3];
		//特定的xml格式字符串
		String str = "<?xml version=\"1.0\" encoding=\"gbk\"?><response><result>succ</result><errorcode>0_sequence</errorcode><number>000009</number></response>";
		String result = str.substring(str.indexOf("<result>")+8,str.indexOf("</result>"));
		String errorcode = str.substring(str.indexOf("<errorcode>")+11,str.indexOf("</errorcode>"));
		String number = str.substring(str.indexOf("<number>")+7,str.indexOf("</number>"));
		
		sinaPayArr[0] = result;
		sinaPayArr[1] = errorcode;
		sinaPayArr[2] = number;
		return sinaPayArr;
		
	}
	/**
	 * @param args
	 */
	/*
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String[] sinaPayArr =  parseString();
		if(sinaPayArr != null && sinaPayArr.length > 1) {
			for(int loop = 0; loop < sinaPayArr.length; loop++) {
				System.out.println("sinaPayArr["+loop+"]==>"+sinaPayArr[loop]);
			}
		}
	}*/
	
    public List xmlElements(String xmlDoc) {
        //创建一个新的字符串
        StringReader read = new StringReader(xmlDoc);
        //创建新的输入源SAX 解析器将使用 InputSource 对象来确定如何读取 XML 输入
        InputSource source = new InputSource(read);
        //创建一个新的SAXBuilder
        SAXBuilder sb = new SAXBuilder();
        
        try {
            //通过输入源构造一个Document
            Document doc = sb.build(source);
            //取的根元素
            Element root = doc.getRootElement();
            System.out.println(root.getName());//输出根元素的名称（测试）
            System.out.println(root.getChildText("number"));
        } catch (JDOMException e) {
            // TODO 自动生成 catch 块
            e.printStackTrace();
        } catch (IOException e) {
            // TODO 自动生成 catch 块
            e.printStackTrace();
        }
        return null;
    }
    public static void jdomsax(){
        strXML doc = new strXML();
        String xml = "<?xml version=\"1.0\" encoding=\"gbk\"?><response result=\"[e-mail]\">"+
        "<result>succ</result><errorcode>0_sequence</errorcode><number>000009</number></response>";
        
        doc.xmlElements(xml);
    }

	 public static void main(String[] args) {
		 String str = "<?xml version=\"1.0\" encoding=\"gbk\"?><response result=\"[e-mail]\">"+
	        "<result>succ</result><errorcode>0_sequence</errorcode><number>000009</number></response>";
	        long start = System.nanoTime();
	        int indexOf = str.indexOf("<number>");
	        long end = System.nanoTime();
	        System.out.println("indexOf time:"+(end-start));
	        start = System.nanoTime();
	        str.contains("<number>");
	        end = System.nanoTime();
	        System.out.println("contains time:"+(end-start));    
	        start = System.nanoTime();
	        str.startsWith("<number>");
	        end = System.nanoTime();
	        System.out.println("startWith time:"+(end-start));
	        start = System.nanoTime();
	        parseString();
	        end = System.nanoTime();
	        System.out.println("My IndexOf time:"+(end-start));
	        start = System.nanoTime();
	        jdomsax();
	        end=System.nanoTime();
	        System.out.println("JDOM SAX time:"+(end-start));
	    }


}