SAX解析xml

最新推荐文章于 2023-02-02 15:03:30 发布

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最新推荐文章于 2023-02-02 15:03:30 发布

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文章标签： SAX解析xml

本文链接：https://blog.youkuaiyun.com/qq_34792830/article/details/84920258

本文详细介绍了一种使用SAX解析器处理XML文件的方法，通过具体示例代码展示了如何定义SAXParseHandler类来读取XML数据，提取用户信息并存储为Java对象。此方法适用于大规模数据处理场景，能够高效地解析XML文件。

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SAXParseHandler.java

package com.hl.chapter1;

import java.util.ArrayList;
import java.util.List;

import javax.swing.text.AbstractDocument.Content;

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

public class SAXParseHandler extends DefaultHandler{
	
	//返回结果集
	List<User> users = null;
	//保存当前节点的内容
	String content = null;
	//保存当前的用户节点信息
	private User user = null;

	@Override
	public void startDocument() throws SAXException {
		super.startDocument();
		//初始化结果集
		users = new ArrayList<>();
		System.out.println("开始解析--------");
	}

	@Override
	public void endDocument() throws SAXException {
		System.out.println("解析结束--------");
		super.endDocument();
	}

	@Override
	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
		super.startElement(uri, localName, qName, attributes);
		//将一个子节点的属性保存
		if("user".equals(qName)){
			user = new User();
			String id = attributes.getValue("id");
			user.setId(id);
		}
	}

	@Override
	public void endElement(String uri, String localName, String qName) throws SAXException {
		super.endElement(uri, localName, qName);
		//将一个节点的值保存
		if("name".equals(qName)){
			user.setName(content);
		}else if ("age".equals(qName)) {
			user.setAge(content);
		}else if ("num".equals(qName)) {
			user.setNum(content);
		}else if ("user".equals(qName)) {
			//将一个完整节点信息添加到结果集中
			users.add(user);
		}
	}

	@Override
	public void characters(char[] ch, int start, int length) throws SAXException {
		super.characters(ch, start, length);
		//内容
		content = new String(ch,start,length);
		
	}
	
	public List<User> getUser(){
		//获取结果集
		return users;
	}

}

user.xml

<?xml version="1.0" encoding="UTF-8"?>
<users>
	<user id="1">
		<name>张三</name>
		<age>23</age>
		<num>5115</num>
	</user>
	<user id="2">
		<name>李四</name>
		<age>18</age>
		<num>5116</num>
	</user>
	<user id="3">
		<name>娜娜</name>
		<age>34</age>
		<num>523</num>
	</user>
</users>

User.java

package com.hl.chapter1;

public class User {

	private String id;
	private String name;
	private String age;
	private String num;
	
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	public String getAge() {
		return age;
	}
	public void setAge(String age) {
		this.age = age;
	}
	public String getNum() {
		return num;
	}
	public void setNum(String num) {
		this.num = num;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", age=" + age + ", num=" + num + "]";
	}
	
}

测试

SAXParseXML.java

package com.hl.chapter1;

import java.util.List;

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

import org.xml.sax.SAXException;

public class SAXParseXML {
	
	public static void main(String[] args) throws Exception {
		SAXParserFactory factory = SAXParserFactory.newInstance();
		SAXParser saxParser = factory.newSAXParser();
		SAXParseHandler saxParseHandler = new SAXParseHandler();
		saxParser.parse("src/com/hl/chapter1/user.xml", saxParseHandler);
		List<User> users = saxParseHandler.getUser();
		for(User user:users){
			System.out.println(user);
		}
	}

}