DOM4j 解析xml

使用DOM4J解析XML响应

最新推荐文章于 2019-07-11 17:45:15 发布

原创最新推荐文章于 2019-07-11 17:45:15 发布 · 933 阅读

0 ·

CC 4.0 BY-SA版权

Java 专栏收录该内容

57 篇文章

订阅专栏

本文介绍了一个Java程序示例，该程序利用DOM4J库解析从HTTP POST请求中获得的XML格式响应数据，并从中抽取特定节点的值。

简述：

解析xml

（参考：http://7-sun.com/text/23790.html）

maven dependency

		<dependency>
			<groupId>maven</groupId>
			<artifactId>dom4j</artifactId>
			<version>1.7-20060614</version>
		</dependency>

代码：

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Iterator;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ShortUrlUtil {
	private static Logger logger = LoggerFactory.getLogger(ShortUrlUtil.class);

	public static int TIMEOUT = 30 * 1000;
	public static String ENCODING = "UTF-8";

	public static void main(String[] args) {
		try{  
			URL url = new URL("http://api.189.cn/EMP/shorturl/long2short?");  
			HttpURLConnection connection = (HttpURLConnection)url.openConnection();  
			//POST Request Define:   
			connection.setDoOutput(true);
			connection.setDoInput(true);
			connection.setUseCaches(false);
			connection.setConnectTimeout(TIMEOUT);
			connection.setRequestMethod("POST");
			// POST params
			StringBuilder sbd = new StringBuilder();
			sbd.append("param=").append("param1");
			
			connection.getOutputStream().write(sbd.toString().getBytes());
			connection.connect();  
			
			// response string
			String responseStr = getResponseStr(connection);
			System.out.println("response xml : \n" + responseStr);
			
			// process response
			String res_message = getValueByKey_XML(responseStr, "res_message");
			System.out.println("\nget res_message: \n" + res_message);;
		}catch(IOException e){  
			e.printStackTrace();
		}
	}


	/**
	 * XML 解析
	 * get value by key
	 * @param replyText
	 * @param key
	 * @return
	 */
	private static String getValueByKey_XML(String replyText, String key){
		String result = "";
		SAXReader reader = new SAXReader();
		ByteArrayInputStream bais = new ByteArrayInputStream(replyText.getBytes());
		Document doc = null;
		try {
			doc  =  reader.read(bais);
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		Element root = doc.getRootElement();
		Iterator nodes = root.elementIterator();
		while(nodes.hasNext()){
			Element node = (Element) nodes.next();
			if(key.equals(node.getName())){
				result = node.getText();
			}
		}
		return result;
	}
	

	/**
	 * 通过HttpConnection 获取返回的字符串
	 * @param connection
	 * @return
	 * @throws IOException
	 */
	private static String getResponseStr(HttpURLConnection connection) 
			throws IOException{
		StringBuffer result = new StringBuffer();
		int responseCode = connection.getResponseCode();

		if (responseCode == connection.HTTP_OK) {
			InputStream in = connection.getInputStream();
			BufferedReader reader = new BufferedReader(
				new InputStreamReader(in, ENCODING));
			String inputLine = "";
			while ((inputLine = reader.readLine()) != null) {
				result.append(inputLine);
			}
		}
		return String.valueOf(result);
	}
}

输出：