sax解析xml

web工程目录

xml文件

<?xml version="1.0" encoding="UTF-8"?>
<persons>
    <person id="1">
        <name>张三</name>
        <age>23</age>
    </person>
    <person id="2">
        <name>李四</name>
        <age>25</age>
    </person>
</persons>

java源程序

MyHandler类，存放数据

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

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

public class MyHandler extends DefaultHandler {

    private HashMap<String,String> map = null;//存储单个解析的完整对象
    private List<HashMap<String,String>> list = null;//存储所有的解析对象
    private String currentTag = null;//正在解析的元素的标签
    private String currentValue = null;//解析当前元素的值
    private String nodeName = null;//解析当前结点名称
    
    
    public MyHandler(String nodeName) {
        // TODO Auto-generated constructor stub
        this.nodeName = nodeName;
    }
    
    
    public List<HashMap<String, String>> getList() {
        return list;
    }


    public void setList(List<HashMap<String, String>> list) {
        this.list = list;
    }


    @Override
    public void startDocument() throws SAXException {
        // TODO Auto-generated method stub
        //当读到第一个开始标签的时候，会触发这个方法
        list = new ArrayList<HashMap<String,String>>();
        
    }
    
    @Override
    public void startElement(String uri, String localName, String qName,
            Attributes attributes) throws SAXException {
        // TODO Auto-generated method stub
        //当遇到文档的开头的时候调用这个方法
        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;
    }
    
    @Override
    public void characters(char[] ch, int start, int length)
            throws SAXException {
        // TODO Auto-generated method stub
        //这个方法是用来处理xml文件所读取到的内容
        if(currentTag!=null && map!=null){
            currentValue = new String(ch,start,length);
            if(currentValue!=null && !currentValue.trim().equals("")&&!currentValue.trim().equals("
")){
                map.put(currentTag, currentValue);
            }
        }
        currentTag = null;//把当前节点的对应的值和标签设置为空
        currentValue = null;
    }
    
    @Override
    public void endElement(String uri, String localName, String qName)
            throws SAXException {
        // TODO Auto-generated method stub
        //遇到结束标记的时候
        if(qName.equals(nodeName)){
            list.add(map);
            map=null;
            
        }
        super.endElement(uri, localName, qName);
    }

}

SaxService类，用于解析xml

import java.io.InputStream;
import java.util.HashMap;
import java.util.List;

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

import com.sax.handler.MyHandler;

public class SaxService {

    public SaxService() {
        // TODO Auto-generated constructor stub
    }

    public static List<HashMap<String,String>> readXML(InputStream inputStream,String nodeName){
        try {
            //创建一个解析xml的工厂对象,使应用程序能够配置和获取基于 SAX 的解析器以解析 XML文档
            SAXParserFactory spf = SAXParserFactory.newInstance();
            SAXParser parser = spf.newSAXParser();//解析xml
            MyHandler handler = new MyHandler(nodeName);
            parser.parse(inputStream, handler);
            inputStream.close();
            return handler.getList();
        } catch (Exception e) {
            // TODO: handle exception
        }
        return null;
    }
}

工具类，用于获取url对象的输入流（xml）

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUtils {

    public HttpUtils() {
        // TODO Auto-generated constructor stub
    }

    public static InputStream getXML(String path){
        InputStream inputStream = null;
        try {
            URL url = new URL(path);
            if(url!=null){
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setConnectTimeout(3000);
                connection.setDoInput(true);
                connection.setRequestMethod("GET");
                int code = connection.getResponseCode();
                if(code == 200){
                    inputStream = connection.getInputStream();
                }
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
        return inputStream;
    }
}

测试类

import java.io.InputStream;
import java.util.HashMap;
import java.util.List;

import com.sax.http.HttpUtils;
import com.sax.sercice.SaxService;

public class Test {

    public Test() {
        // TODO Auto-generated constructor stub
    }
 
    public static void main(String[] args) {
        String path = "http://169.254.32.172:8080/myhttp/person.xml";
        InputStream inputStream = HttpUtils.getXML(path);
        try {
            List<HashMap<String,String>> list = SaxService.readXML(inputStream, "person");
            for(HashMap<String,String> map : list){
                System.out.println(map.toString());
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

结果：

{id=1, age=23, name=张三}
{id=2, age=25, name=李四}