package xml;

import java.io.IOException;
import java.io.StringReader;
import java.util.Iterator;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory; 
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;



import
 
 org.dom4j.DocumentHelper;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
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;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * @description
 
 4種 XML格式的字串讀取方式 簡單比較
 *  
 * @date 2015年12月31日
 */
public class ReadXmlString {

    public static void main(String[] args) throws Exception {
        String xmlStr = "<message><a>try</a><b>try</b><c>try</c><d>try</d><e>try</e><f>try</f><g>try</g><h>try</h><i>do you konw？</i><世界>你好！</世界></message>"
 
;
        long begin = System.currentTimeMillis();
        parse4Dom(xmlStr);
        long after = System.currentTimeMillis();
        System.out.println("DOM用時" + (after - begin) + "毫秒");

        begin = System.currentTimeMillis();
        parse4Sax(xmlStr);
        after = System.currentTimeMillis();
        System.out.println("SAX用時" + (after - begin) + "毫秒");

        begin = System.currentTimeMillis();
        parse4DOM4j(xmlStr);
        after = System.currentTimeMillis();
        System.out.println("DOM4j用時" + (after - begin) + "毫秒");

        begin = System.currentTimeMillis();
        parse4JDOM(xmlStr);
        after = System.currentTimeMillis();
        System.out.println("JDOM用時" + (after - begin) + "毫秒");
    }

    /**
     * @description JDOM解析,需要下載對應的jar包  
     * @param xmlStr
     * @throws Exception 
     * @time 2016年1月1日 上午2:04:03
     */
    private static void parse4JDOM(String xmlStr) throws Exception { 
        SAXBuilder builder=new SAXBuilder(false);
        org.jdom.Document doc = builder.build(new InputSource(new StringReader(xmlStr)));   
        org.jdom.Element root = doc.getRootElement(); // 得到根元素   
        System.out.println("根節點" + root.getName());   

        List<org.jdom.Element> list = root.getChildren(); // 得到元素的集合   
        //List studentList = students.getChildren("student"); // 得到指定元素（節點）的集合   

        if( list!=null){   
            for (int i = 0; i < list.size(); i++) {   
                 org.jdom.Element element = (org.jdom.Element)list.get(i);   
                 System.out.println("節點=" + element.getName() + "\ttext=" + element.getValue());   
             }   
          }   
    }

    /**
     * @description DOM4J解析,需要下載對應的jar包
     * @param xmlStr
     * @throws Exception
     * @time 2016年1月1日 上午1:52:58
     */
    private static void parse4DOM4j(String xmlStr) throws Exception { 
        org.dom4j.Document doc=(org.dom4j.Document)DocumentHelper.parseText(xmlStr);   
        org.dom4j.Element message = doc.getRootElement();   
        System.out.println("根節點" + message.getName());   
        Iterator elements = message.elementIterator();   
        while(elements.hasNext()){   
           org.dom4j.Element element = (org.dom4j.Element)elements.next();   
           System.out.println("節點" + element.getName() + "\ttext=" + element.getText());
           System.out.println();  
        }
    }

    /**
     * @description java自帶的SAX解析
     * @param xmlStr
     * @author liuquan
     * @throws Exception
     * @date 2015年12月31日
     */
    private static void parse4Sax(String xmlStr) throws Exception {
        SAXParserFactory saxfac = SAXParserFactory.newInstance();
        SAXParser saxparser = saxfac.newSAXParser();
        // 為演示方便 寫成匿名內部類
        saxparser.parse(new InputSource(new StringReader(xmlStr)),
                new myHandler());
    }

    /**
     * @description java自帶的DOM解析.
     * @param xmlStr
     * @author liuquan
     * @throws Exception
     * @date 2015年12月31日
     */
    private static void parse4Dom(String xmlStr) throws Exception {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        Document doc = builder.parse(new InputSource(new StringReader(xmlStr)));
        Element message = doc.getDocumentElement();
        NodeList list = message.getChildNodes();
        if (list != null) {
            for (int i = 0; i < list.getLength(); i++) {
                Node node = list.item(i);
                System.out.println("節點=" + node.getNodeName() + "\ttext="
                        + node.getFirstChild().getNodeValue());
            }
        }
    }
}

/**
 * @Description SAX解析的處理器 sax解析要多寫一個類，但是非常快
 * @author liuquan
 * @time 2016年1月1日 上午1:53:03
 */
class myHandler extends DefaultHandler {

    private StringBuffer buf;
    private String str;

    public myHandler() {
        super();
    }

    public void startDocument() throws SAXException {
        buf = new StringBuffer();
        System.out.println("*******開始解析XML*******");
    }

    public void endDocument() throws SAXException {
        System.out.println("*******XML解析結束*******");
    }

    public void endElement(String namespaceURI, String localName,
            String fullName) throws SAXException {
        str = buf.toString();
        System.out.println("節點=" + fullName + "\tvalue=" + buf + " 長度="
                + buf.length());
        buf.delete(0, buf.length());
    }

    public void characters(char[] chars, int start, int length)
            throws SAXException {
        // 將元素內容累加到StringBuffer中
        buf.append(chars, start, length);
    }
}