java解析xml数据---sax解析器

下面是handler解析数据的方法

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;// 存储全部的解析对象
	private String currentTag = null; // 正在解析的元素的标签
	private String currentValue = null;// 正在解析的元素的值
	private String nodeName = null;// 解析节点的名称

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

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

	public void startDocument() throws SAXException {
		// 当读到第一个开始标签的时候，开始触发
		list = new ArrayList<HashMap<String, String>>();
	}

	public void startElement(String uri, String localName, String qName,
			Attributes attributes) throws SAXException {
		// 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;
	}

	public void characters(char[] ch, int start, int length)
			throws SAXException {
		// 处理从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("\n")) {
				map.put(currentTag, currentValue);
			}
		}
		currentTag = null;
		currentValue = null;
	}

	public void endElement(String uri, String localName, String qName)
			throws SAXException {
		// 遇到结束标记的时候，调用此方法
		if (qName.equals(nodeName)) {
			list.add(map);
			map = null;
		}
	}

}

下面是读取输入流中xml数据，并将这些数据一List方式返回

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 static List<HashMap<String, String>> readXML(InputStream input, String nodeName){
		
		try {
			//创建一个解析xml的工厂对象
			SAXParserFactory apf = SAXParserFactory.newInstance();
			SAXParser parser = apf.newSAXParser();//解析xml内容  
			MyHandler handler = new MyHandler(nodeName);
			parser.parse(input, handler);//用给定的handler解析input输入流中的内容
			input.close();
			return handler.getList();
			
		} catch (Exception e) {
			System.out.println(e);
		}
		return null;
	}
}

下面是从服务器中得到xml文件，并将其转化为数据流

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

public class HttpUtils {

	public static InputStream getXML(String path) {

		InputStream input = null;

		try {
			URL url = new URL(path);
			if (url != null) {
				HttpURLConnection connection = (HttpURLConnection) url
						.openConnection();
				connection.setReadTimeout(3000);
				connection.setDoInput(true);
				connection.setRequestMethod("GET");
				int code = connection.getResponseCode();
				if (code == 200) {
					input = connection.getInputStream();
				}
			}
		} catch (Exception e) {
			// TODO: handle exception
		}

		return input;
	}
}

下面就是测试代码了

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

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

public class Test {

	public static void main(String[] args) {
		String path = "http://127.0.0.1:8080/myhttp/person.xml";
		try {
			InputStream input = HttpUtils.getXML(path);
			List<HashMap<String, String>> list = SaxService.readXML(input,
					"person");
			
			for(HashMap<String, String> map :list){
				System.out.println("-test->"+map.toString());
			}

		} catch (Exception e) {
			System.out.println(e);
		}
	}

}