package com.imooc.xmlTest;

import org.dom4j.DocumentHelper;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;
import org.jdom2.output.Format;
import org.jdom2.output.XMLOutputter;
import org.testng.annotations.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

public class JUnitTest1 {

   public void DOMCreateXML() throws ParserConfigurationException, TransformerException {
       DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
       DocumentBuilder db=dbf.newDocumentBuilder();
       Document document=db.newDocument();
       document.setXmlStandalone(true);
       Element bookstore=document.createElement("bookstore");
       Element book=document.createElement("book");
       book.setAttribute("id","1");
       Element name=document.createElement("name");
       name.setTextContent("小王子");
       book.appendChild(name);
       bookstore.appendChild(book);
       document.appendChild(bookstore);
       TransformerFactory tff=TransformerFactory.newInstance();
       Transformer tf=tff.newTransformer();
       tf.setOutputProperty(OutputKeys.INDENT,"yes");
       tf.transform(new DOMSource(document),new StreamResult(new File("demo2/books.xml")));
   }
   public void SAXCreateXML() throws ParserConfigurationException, IOException, SAXException, TransformerConfigurationException {
       SAXTransformerFactory tff=(SAXTransformerFactory)SAXTransformerFactory.newInstance();
       TransformerHandler handler=tff.newTransformerHandler();
       Transformer tf=handler.getTransformer();
       tf.setOutputProperty(OutputKeys.ENCODING,"UTF-8");
       tf.setOutputProperty(OutputKeys.INDENT,"yes");
       Result result=new StreamResult(new FileOutputStream(new File("demo2/books1.xml")));
       handler.setResult(result);
       handler.startDocument();
       AttributesImpl attr=new AttributesImpl();
       handler.startElement("","","bookstore",attr);
           attr.clear();
           attr.addAttribute("","","id","","1");
           handler.startElement("","","book",attr);
           attr.clear();
           handler.startElement("","","name",attr);
           String name="小王子";
           handler.characters(name.toCharArray(),0,name.length());
           handler.endElement("","","name");
           handler.endElement("","","book");
           handler.endElement("","","bookstore");
           handler.endDocument();
   }
   public void JDOMCreateXML() throws IOException {
       org.jdom2.Element bookstore=new org.jdom2.Element("bookstore");
       org.jdom2.Document document=new org.jdom2.Document(bookstore);
       org.jdom2.Element book=new org.jdom2.Element("book");
       book.setAttribute("id","1");
       org.jdom2.Element name=new org.jdom2.Element("name");
       name.setText("小王子");
       book.addContent(name);
       bookstore.addContent(book);
       Format format=Format.getPrettyFormat();
       format.setEncoding("gbk");
       XMLOutputter xmlOutputter=new XMLOutputter(format);
       xmlOutputter.output(document,new FileOutputStream("demo2/books2.xml"));
   }
   public void DOM4JCreateXML() throws IOException {
       org.dom4j.Document document= DocumentHelper.createDocument();
       org.dom4j.Element bookstore=document.addElement("bookstore");
       org.dom4j.Element book=bookstore.addElement("book");
       book.addAttribute("id","1");
       org.dom4j.Element name=book.addElement("name");
       name.setText("小王子");
       OutputFormat outputFormat=OutputFormat.createPrettyPrint();
       XMLWriter xmlWriter=new XMLWriter(new FileOutputStream("demo2/books3.xml"),outputFormat);
       xmlWriter.write(document);
       xmlWriter.close();
   }
   @Test
   public void testPerformance() throws Exception{
       System.out.println("性能测试:");
       long start=System.currentTimeMillis();
       DOMCreateXML();
       System.out.println("DOM:"+(System.currentTimeMillis()-start));
       start=System.currentTimeMillis();
       SAXCreateXML();
       System.out.println("SAX:"+(System.currentTimeMillis()-start));
       start=System.currentTimeMillis();
       JDOMCreateXML();
       System.out.println("JDOM:"+(System.currentTimeMillis()-start));
       start=System.currentTimeMillis();
       DOM4JCreateXML();
       System.out.println("DOM4J:"+(System.currentTimeMillis()-start));
   }
}

SAX的测试结果为0，这是不是有问题

生成xml文件性能对比

生成xml性能对比

生成xml的四种方式的性能对比：SAX > DOM4J > JDOM > DOM
在一个课程测试用例中四种方式的用时(Ms)：
DOM：418
SAX：3
JDOM：158
DOM4J：59

生成xml的四种方式的性能对比：SAX > DOM4J > JDOM > DOM
在一个课程测试用例中四种方式的用时(Ms)：
DOM：418
SAX：3
JDOM：158
DOM4J：59
DOM/SAX官方自带：

DOM生成DOM树加载到内存，方便修改，性能慢。

SAX性能最高，但是不能返回修改便签中的内容

DOM4J相对综合最好，应用广泛