Sax解析XML实现查询

Sax解析实现查询

新建一个SaxParseXml类继承DefaultHandler

public class SaxParseXml extends DefaultHandler {}

代码

package com.bosssoft.hr.train.xml;

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

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

/**
 * @作者 吴志鸿
 * @maven 3.6.3
 * @jdk 1.8
 */
public class SaxParseXml extends DefaultHandler {


    private HashMap<String,String> map = null;
    private List<HashMap<String,String>> list = null;
    private String currentTag = null;
    private String currentValue = null;
    private String nodeName = null;


    public SaxParseXml(String nodeName){
        this.nodeName = nodeName;
    }

    public List<HashMap<String,String>> getList(){
        return list;
    }


    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        super.endElement(uri, localName, qName);
        if(qName.equals(nodeName)){
            list.add(map);
            map = null;
        }
    }

    @Override
    public void startDocument() throws SAXException {
        super.startDocument();
        list = new ArrayList();
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        super.characters(ch, start, length);
        if(currentTag != null && map != null){
            currentValue = new String(ch,start,length);
            if(currentValue!=null&&!currentValue.trim().equals("")&&!currentValue.trim().equals("\n")){
                map.put(currentTag,currentValue);
            }
        }
        currentTag = null;
        currentValue = null;
    }


    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        super.startElement(uri, localName, qName, attributes);
        if(qName.equals(nodeName)){
            map = new HashMap<String, String>();
            if(attributes != null && map != null){
                for(int i=0; i<attributes.getLength(); i++){
                    map.put(attributes.getQName(i),attributes.getValue(i));
                }
            }
        }
        currentTag = qName;
    }

    //查询全部用户
    public static void queryall() throws ParserConfigurationException, SAXException, IOException {
        SAXParserFactory saxParserFactor = SAXParserFactory.newInstance();
        SAXParser saxParser = saxParserFactor.newSAXParser();
        SaxParseXml item = new SaxParseXml("student");
        saxParser.parse("src/com/bosssoft/hr/train/xml/student.xml",item);
        List<HashMap<String, String>> list1 = item.getList();
        for (HashMap<String, String> p : list1) {
            System.out.println(p.toString());
        }
    }
}