Java解析XML文件方法介紹（SAX,JDOM,DOM4J）

示例XML文件：

<?xml version="1.0" encoding="utf-8" ?>
<class>
    <student>
        <firstname>cxx1</firstname>
        <lastname>Bob1</lastname>
        <nickname>stars1</nickname>
        <marks>85</marks>
    </student>
    <student rollno="493">
        <firstname>cxx2</firstname>
        <lastname>Bob2</lastname>
        <nickname>stars2</nickname>
        <marks>85</marks>
    </student>
    <student rollno="593">
        <firstname>cxx3</firstname>
        <lastname>Bob3</lastname>
        <nickname>stars3</nickname>
        <marks>85</marks>
    </student>
</class>

SAX方式解析

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

public class XMLParse {
    public static void main(String args[]) throws Exception{
        SAXParserFactory factory=SAXParserFactory.newInstance();
        SAXParser saxParser=factory.newSAXParser();
        SAXDemoHandel handel=new SAXDemoHandel();
        saxParser.parse("",handel);
    }
}

class SAXDemoHandel extends DefaultHandler{
    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        super.startElement(uri, localName, qName, attributes);
        if (qName.equals("student")){
            System.out.println("============開始遍歷student=============");
            //System.out.println(attributes.getValue("rollno"));
        }
        else if (!qName.equals("student")&&!qName.equals("class")){
            System.out.print("節點名稱:"+qName+"----");
        }
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        super.endElement(uri, localName, qName);
        if (qName.equals("student")){
            System.out.println(qName+"遍歷結束");
            System.out.println("============結束遍歷student=============");
        }
    }

    @Override
    public void startDocument() throws SAXException {
        super.startDocument();
        System.out.println("sax解析開始");
    }

    @Override
    public void endDocument() throws SAXException {
        super.endDocument();
        System.out.println("sax解析結束");
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        super.characters(ch, start, length);
        String value = new String(ch,start,length).trim();
        if (!value.equals("")) {
            System.out.println(value);
        }
    }
}

JDOM解析

<!--引入jdom依賴 -->
<dependency>
    <groupId>org.jdom</groupId>
    <artifactId>jdom</artifactId>
    <version>1.1.3</version>
</dependency>

import org.jdom.Attribute;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;

import javax.swing.text.Element;
import javax.xml.stream.events.Attribute;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.List;

public class JDOMParse {
    public void main(String args[]) throws Exception{
        //1.創建SAXBuilder對象
        SAXBuilder saxBuilder = new SAXBuilder();
        //2.創建輸入流
        InputStream is = new FileInputStream(new File("src/main/resources/demo.xml"));
        //3.將輸入流加載到build中
        Document document = saxBuilder.build(is);
        //4.獲取根節點
        Element rootElement = document.getRootElement();
        //5.獲取子節點
        List<Element> children = rootElement.getChildren();

        for(Element child : children){
            List<Attribute> attributes=child.getAttributes();
            for (Attribute attr : attributes) {
                System.out.println(attr.getName()+":"+attr.getValue());
            }
            List<Element> childrenList = child.getChildren();
            System.out.println("======獲取子節點-start======");
            for (Element o : childrenList) {
                System.out.println("節點名:"+o.getName()+"---"+"節點值:"+o.getValue());
            }
            System.out.println("======獲取子節點-end======");
        }
    }
}

DOM4J解析

 <!-- 引入dom4j依賴 -->
 <dependency>
     <groupId>dom4j</groupId>
     <artifactId>dom4j</artifactId>
     <version>1.6.1</version>
</dependency>

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import java.io.File;
import java.util.Iterator;
import java.util.List;

Public class Dom4JDemo {
    public static void main(String[] args) throws Exception {
        //1.創建Reader對象
        SAXReader reader = new SAXReader();
        //2.加載xml
        Document document = reader.read(new File("src/main/resources/demo.xml"));
        //3.獲取根節點
        Element rootElement = document.getRootElement();
        Iterator iterator = rootElement.elementIterator();
        while (iterator.hasNext()){
            Element stu = (Element) iterator.next();
            List<Attribute> attributes = stu.attributes();
            System.out.println("======獲取屬性值======");
            for (Attribute attribute : attributes) {
                System.out.println(attribute.getValue());
            }
            System.out.println("======遍歷子節點======");
            Iterator iterator1 = stu.elementIterator();
            while (iterator1.hasNext()){
                Element stuChild = (Element) iterator1.next();
                System.out.println("節點名："+stuChild.getName()+"---節點值："+stuChild.getStringValue());
            }
        }
    }
}