XML データ解析の 3 つの方法を詳しく説明したサンプル コード

<?xml version="1.0" encoding="utf-8"?>
<students>

        <student id = "1001">
             <id>1</id>
             <name>杨威</name>
             <address>大连</address>
             <age>21</age>
        </student>

        <student id = "1002">
             <id>2</id>
             <name>劉海洋</name>
             <address>深圳</address>
             <age>23</age>
        </student>

        <student id = "1003">
             <id>3</id>
             <name>王小波</name>
             <address>廣州</address>
             <age>22</age>
        </student>

</students>

[code]package com.kuxiao.train.xml;

import java.io.File;

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

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class XmlParseTest {

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

        //xml doc解析步骤
        //1、获取解析工厂对象
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        //2、构建解析器对象
        DocumentBuilder   db = dbf.newDocumentBuilder();
        //3、构建docment对象
        Document  doc = db.parse(new File("person.xml"));

        Element ele = doc.getDocumentElement();

        //实现解析逻辑
        NodeList list = doc.getElementsByTagName("student");

        for(int i = 0; i < list.getLength();i++)
        {
              Element element = (Element) list.item(i);
              String attrid = element.getAttribute("id");
              System.out.println("attrid = " + attrid);
              Element  element1 = (Element) element.getElementsByTagName("id").item(0);
              String id = element1.getFirstChild().getNodeValue();
              System.out.println(id);
              element1 = (Element) element.getElementsByTagName("name").item(0);
              String name = element1.getFirstChild().getNodeValue();
              System.out.println(name);
              element1 = (Element) element.getElementsByTagName("address").item(0);
              String address = element1.getFirstChild().getNodeValue();
              System.out.println(address);

        }       

    }

}

[code]package com.kuxiao.train.xml.sax;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Stack;

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

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class TestSax {

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

        SAXParserFactory spf = SAXParserFactory.newInstance();
        SAXParser sp = spf.newSAXParser();
        List<Student> list = new ArrayList<>();
        sp.parse(new File("student.xml"), new MyHandler(list));
        System.out.println(list);

    }
}

class MyHandler extends DefaultHandler {

    private Stack<String> stack = new Stack<>();
    private Student student;
    private List<Student> mList = null;

    public MyHandler(List<Student> list)
    {
          this.mList = list;
    }
    @Override
    public void startDocument() throws SAXException {

        System.out.println("解析文档开始了...");
    }

    @Override
    public void startElement(String uri, String localName, String qName,
            Attributes attributes) throws SAXException {
            if(qName.equals("学生"))
            {
                student = new Student();
                if(attributes.getLength() != 0)
                {
                     for(int i = 0; i < attributes.getLength();i++)
                     {
                            String id = attributes.getValue(i);
                            student.setId(Integer.parseInt(id));
                     }
                }
            }
            /*if(qName.equals("姓名"))
            {
                 stack.push(qName);
            }
            if(qName.equals("年龄"))
            {
                 stack.push(qName);
            }
            if(qName.equals("性别"))
            {
                 stack.push(qName);
            }*/
            stack.push(qName);
    }

    @Override
    public void characters(char[] ch, int start, int length)
            throws SAXException {
             String qName = stack.peek();
            if(qName.equals("性别")){
                student.setGender(new String(ch,start,length));
            }
            if(qName.equals("姓名")){
                student.setName(new String(ch,start,length));
            }
            if(qName.equals("年龄")){
                student.setAge(new String(ch,start,length));
            }
    }

    @Override
    public void endElement(String uri, String localName, String qName)
            throws SAXException {
            stack.pop();
            if(qName.equals("学生"))
            {
                mList.add(student);
                student = null;
            }
    }

    @Override
    public void endDocument() throws SAXException {
         System.out.println("解析文档结束了.....");
    }

}