dom4j 解析xml

package com.itheima.dom4j;


import java.io.FileOutputStream;
import java.util.List;


import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import org.junit.Test;


public class Demo4jDemo2 {
@Test
public void attr() throws Exception{
SAXReader reader = new SAXReader();
Document dom = reader.read("book.xml");
Element root = dom.getRootElement();

Element bookEle = root.element("書");
//bookEle.addAttribute("出版社", "傳智出版社");
// String str = bookEle.attributeValue("出版社");
// System.out.println(str);
Attribute attr = bookEle.attribute("出版社");
attr.getParent().remove(attr);

XMLWriter writer = new XMLWriter(new FileOutputStream("book.xml"),OutputFormat.createPrettyPrint());
writer.write(dom);
writer.close();
}

@Test
public void del() throws Exception{
SAXReader reader = new SAXReader();
Document dom = reader.read("book.xml");
Element root = dom.getRootElement();

Element price2Ele = root.element("書").element("特價");
price2Ele.getParent().remove(price2Ele);


XMLWriter writer = new XMLWriter(new FileOutputStream("book.xml"),OutputFormat.createPrettyPrint());
writer.write(dom);
writer.close();
}

@Test
public void update()throws Exception{
SAXReader reader = new SAXReader();
Document dom = reader.read("book.xml");
Element root = dom.getRootElement();

root.element("書").element("特價").setText("4.0元");

XMLWriter writer = new XMLWriter(new FileOutputStream("book.xml"),OutputFormat.createPrettyPrint());
writer.write(dom);
writer.close();
}

@Test
public void add()throws Exception{
SAXReader reader = new SAXReader();
Document dom = reader.read("book.xml");
Element root = dom.getRootElement();
//憑空創建<特價>節點,設置標籤體
Element price2Ele = DocumentHelper.createElement("特價");
price2Ele.setText("40.0元");
//獲取父標籤<書>將特價節點掛載上去
Element bookEle = root.element("書");
bookEle.add(price2Ele);

//將內存中的dom樹會寫到xml文件中,從而使xml中的數據進行更新
// FileWriter writer = new FileWriter("book.xml");
// dom.write(writer);
// writer.flush();
// writer.close();
XMLWriter writer = new XMLWriter(new FileOutputStream("book.xml"),OutputFormat.createPrettyPrint());
writer.write(dom);
writer.close();
}

@Test
public void find() throws Exception{
SAXReader reader = new SAXReader();
Document dom = reader.read("book.xml");
Element root = dom.getRootElement();

List<Element> list =  root.elements();
Element book2Ele = list.get(1);
System.out.println(book2Ele.element("書名").getText());

}
}