WebServer Project-02-XML解析

XML：Extensible Markup Language，可扩展标记语言，左卫门数据的一种存储格式或用于存储软件的参数，程序解析此配置文件，就可以达到不修改代码就能更改程序的目的。

<?xml version="1.0" encoding="UTF-8"?>
<persons>
    <person>
        <name>至尊宝</name>>
        <age>9000</age>
    </person>
    <person>
        <name>白晶晶</name>>
        <age>2000</age>
    </person>
</persons>

package server.study;

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

import java.io.IOException;

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

/**
 * 熟悉SAX解析流程
 * Created by 16114 on 2019/8/22.
 *
 */
public class XmlTest01 {
    public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
        //SAX解析
        //1.获取解析工厂
        SAXParserFactory factory = SAXParserFactory.newInstance();
        //2.从解析工厂获取解析器
        SAXParser parser = factory.newSAXParser();
        //3.编写处理器

        //4.加载文档Document注册处理器
        PHandler handler = new PHandler();
        //5.解析
        parser.parse(Thread.currentThread().getContextClassLoader()
                        .getResourceAsStream("server/study/p.xml") ,handler);
    }
}
class PHandler extends DefaultHandler{
    @Override
    public void startDocument() throws SAXException {
        System.out.println("---解析文档开始---");
    }

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

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        String contents = new String(ch,start,length).trim();
        if (contents.length() > 0) {
            System.out.println("内容为-->" + contents);
        } else {
            System.out.println("内容为-->" + "空");
        }
    }

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
       // super.startElement(uri, localName, qName, attributes);
        System.out.println(qName+ "--->解析开始 ");
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        //super.endElement(uri, localName, qName);
        System.out.println(qName+ "--->解析结束");
    }
}

package server.study;

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

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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

/**
 * 熟悉SAX解析流程
 * Created by 16114 on 2019/8/22.
 *
 */
public class XmlTest02 {
    public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
        //SAX解析
        //1.获取解析工厂
        SAXParserFactory factory = SAXParserFactory.newInstance();
        //2.从解析工厂获取解析器
        SAXParser parser = factory.newSAXParser();
        //3.编写处理器

        //4.加载文档Document注册处理器
        PersonHandler handler = new PersonHandler();
        //5.解析
        parser.parse(Thread.currentThread().getContextClassLoader()
                .getResourceAsStream("server/study/p.xml") ,handler);
        //获取数据
        List<Person> persons = handler.getPersons();
        for (Person p:persons
             ) {
            System.out.println(p.getName()+"-->"+p.getAge());
        }
    }
}
class PersonHandler extends DefaultHandler{
    private List<Person> persons;
    private Person person;
    private String tag; //存储操作标签

    public List<Person> getPersons() {
        return persons;
    }

    @Override
    public void startDocument() throws SAXException {
        persons = new ArrayList<Person>();
        //System.out.println("---解析文档开始---");
    }

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

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        // super.startElement(uri, localName, qName, attributes);
        System.out.println(qName+ "--->解析开始 ");

        if (null != qName){
            tag = qName; //存储
            if (tag.equals("person")){
                person = new Person();
            }
        }
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        String contents = new String(ch,start,length).trim();
        if (null != tag) { //处理了空
            if (tag.equals("name")) {
                person.setName(contents);
            } else if (tag.equals("age")) {
                if (contents.length() > 0) {
                    person.setAge(Integer.valueOf(contents));
                }
            }
        }
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        //super.endElement(uri, localName, qName);
        System.out.println(qName+ "--->解析结束");
        if (null != qName) {
            if (qName.equals("person")) {
                persons.add(person);
            }
        }
        tag = null;
    }
}