<?xml version="1.0" encoding="GBK"?>

<Books>

  <book id="1">

    <name>java基础</name>

    <price>25.8</price>

    <describe>一本好书！</describe>

  </book>

  <book id="2">

    <price>22</price>

    <describe>学习页面设计！</describe>

  </book>

  <book id="3" type="书籍">

    <name>数据库的安装与维护</name>

    <price>22</price>

    <describe>学习页面设计！</describe>

  </book>

</Books>

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

import java.util.Iterator;

import org.dom4j.Document;

import org.dom4j.Element;

import org.dom4j.io.OutputFormat;

import org.dom4j.io.SAXReader;

import org.dom4j.io.XMLWriter;

public class XmlTest {

     Document document;

    public static void main(String[] args) throws Exception {

        XmlTest test=new XmlTest();

        test.getRoot();

        test.addElement();

        test.removeElement();

        test.modifyElement();

        test.saveXml();

        test.selectElement("3");  

List<Element> list=test.dgXml(test.document.getRootElement(), "describe");
          System.out.println(list);

    }

    //获得文档对象和根节点

    public void getRoot() throws Exception{

         SAXReader reader = new SAXReader();

         document= reader.read(this.getClass().getResourceAsStream("NewFile.xml"));

         Element ele=document.getRootElement();

         System.out.println(ele.getName());

    }

    //保存

    public void saveXml() throws Exception{

        FileWriter fw=new FileWriter("E:\\ProgramFiles\\Myeclipse\\Workspaces\\fanshe_Git\\src\\ldl\\xmlAndJSON\\NewFile.xml");

        //设置写入格式

        OutputFormat format=OutputFormat.createPrettyPrint();

        //设置字符格式

        format.setEncoding("GBK");

        XMLWriter xw=new XMLWriter(fw,format);

        xw.write(document);

        xw.flush();

        xw.close();

        fw.close();

    }

    //添加节点

    public void addElement(){

        //获得根节点

        Element ele=document.getRootElement();

        //在根节点下添加子节点

        Element book=ele.addElement("book");

        //添加子节点的属性和值

        book.addAttribute("id", "2");

        book.addAttribute("type", "书籍");

        //在子节点下添加子节点并赋值

        Element name=book.addElement("name");

        Element price=book.addElement("price");

        Element describe=book.addElement("describe");

        name.addText("JSP页面");

        price.addText("22");

        describe.addText("学习页面设计！");

    }

    //删除节点

    public void removeElement(){

        //获得根节点

        Element root=document.getRootElement();

        //获得根节点下所有节点的迭代器

        Iterator<Element> iter=root.elementIterator();

        //遍历所有节点

        while(iter.hasNext()){

            //获得该节点

            Element elem=iter.next();

            if(elem.attributeValue("id").equals("2")){

                //获得该节点下，name节点

                Element t=elem.element("name");

                //删除子节点

                elem.remove(t);

            }

        }

    }

    //根据id查询节点

    public void selectElement(String id){

        //获取根节点

        Element root=document.getRootElement();

        //获取根节点的子节点的迭代器

        Iterator<Element> ite=root.elementIterator();

        while(ite.hasNext()){

            Element elem=ite.next();

            if(elem.attributeValue("id").equals(id)){

                Iterator<Element> it=elem.elementIterator();

                while(it.hasNext()){

                    System.out.println(it.next().getText());

                }

                break;

            }

        }

    }

    //修改子节点

    public void modifyElement(){

        //获取根节点

        Element root=document.getRootElement();

        //获取根节点下所有子节点的迭代器

        Iterator<Element> it=root.elementIterator();

        while(it.hasNext()){

            Element ele=it.next();

            if(ele.attributeValue("id").equals("3")){

                Element e=ele.element("name");

                e.setText("数据库的安装与维护");

            }

        }

    }

}

//递归实现无限极节点遍历

    public List<Element> dgXml(Element e,String name){

        List<Element> list=new ArrayList<Element>();

        Iterator<Element> it=e.elementIterator();//获取当前节点的子节点的集合

        while(it.hasNext()){

            Element ele=it.next();//获取子节点

            if(ele.getName().equals(name)){//子节点名字和要找的节点一样，添入集合

                list.add(ele);

            }

        }

        if(list.size()>){//如果集合不为空，返回集合

            return list;

        }else{

            Iterator<Element> iter=e.elementIterator();//重新获取节点下的子节点的集合

            while(iter.hasNext()){

                List<Element> lists=dgXml(iter.next(),name);//递归查询每个子节点

                list.addAll(lists);//把所有返回的集合添加作为一个集合

            }

            return list;

        }

    }

public class Student {

    private String name;

    private int age;

    public Student(String name, int age) {

        super();

        this.name = name;

        this.age = age;

    }

}

public class JSONDemo {

    public static void main(String[] args) {

        String s=JSON.toJSONString(new Student("张三",18));

        System.out.println(s);

        String json="{\"age\":18,\"name\":\"张三\"}";

        Student stu=JSON.parseObject(json, Student.class);

        System.out.println("姓名是："+stu.getName()+",年龄是："+stu.getAge());

    }

}