从服务器上获取XML资源，并在客户端上解析下来，
实现的步骤如下：
1.pull 解析网络上XML文件的内容
1.新建一个URL链接对象、并打开链接（HttpURLConnection）
2.设置一些参数，比如链接超时，请求方式（GET、POST）等
3.得到xml的输入流getInputStream（）；
4.用pull解析XML文件
1.实例化一个newPullParser对象
2.得到解析的类型getEventType
3.从START_DOCUMENT、START_TAG、END_TAG、END_DOCUMENT对XML进行解析，返回解析的内容
5.解析过程中需要用到Bean的一些get、set、以及构造函数的一些方法
实现的效果如下：
这时候会出现以下异常：
Error parsing document. (position:line -1,column -1) caused by: org.apache.harmony.xml.ExpatParser$ParseException: At line 2,column 0: XML or text declaration not at start of entity; nested exception is:
产生异常的原因是因为：JSP代码中的<%@ page language="java" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>被放在最前面了，这样会导致XML前面出现空行，所以解析的时候会报-1行和-1列
在XML解析文档的时候默认的是从<?xml version="1.0" encoding="UTF-8"?>开始的
解决方法如下：
@H_403_50@<?xml version="1.0" encoding="UTF-8"?><%@ page language="java" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <newslist> <c:forEach items="${newes}" var="news"> <news id="${news.id}"> <title>${news.title}</title> <timelength>${news.timelength}</timelength> </news> </c:forEach> </newslist>客户端实现的代码：
bean的实现News的方法和解析的代码如下：public class NewsService {
public static List<News> getLastNews() throws Exception {
String path = "http://10.8.2.33/WebXMLDemo/ServletForXML";
HttpURLConnection connection = (HttpURLConnection) new URL(path)
.openConnection();
connection.setConnectTimeout(5000);
connection.setRequestMethod("GET");
if (connection.getResponseCode() == 200) {
InputStream xml = connection.getInputStream();
return parseXML(xml);
}
return null;
}
private static List<News> parseXML(InputStream xml) throws Exception {
List<News> newes = null;
News news = null;
// XmlPullParser pullParser = Xml.newPullParser();
XmlPullParser pullParser=XmlPullParserFactory.newInstance().newPullParser();
pullParser.setInput(xml,"UTF-8");
int event = pullParser.getEventType();
while (event != XmlPullParser.END_DOCUMENT) {
switch (event) {
case XmlPullParser.START_DOCUMENT:
newes = new ArrayList<News>();
break;
case XmlPullParser.START_TAG:
if ("news".equals(pullParser.getName())) {
int id = new Integer(pullParser.getAttributeValue(0));
news = new News();
news.setId(id);
}
if ("title".equals(pullParser.getName())) {
news.setTitle(pullParser.nextText());
}
if ("timelength".equals(pullParser.getName())) {
news.setTimelength(new Integer(pullParser.nextText()));
}
break;
case XmlPullParser.END_TAG:
if ("news".equals(pullParser.getName())) {
newes.add(news);
news = null;
}
break;
}
event=pullParser.next();
}
return newes;
}
}实现Activity的方法如下：
public class GetXMLDemoActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.list);
ListView listView = (ListView) findViewById(R.id.list);
String length = getResources().getString(R.string.length);
try {
List<News> newlist = NewsService.getLastNews();
List<HashMap<String,Object>> data = new ArrayList<HashMap<String,Object>>();
for (News news : newlist) {
HashMap<String,Object> item = new HashMap<String,Object>();
item.put("id",news.getId());
item.put("title",news.getTitle());
item.put("timelength",length + news.getTimelength());
data.add(item);
}
SimpleAdapter adapter = new SimpleAdapter(this,data,R.layout.list_item,new String[] { "title","timelength" },new int[] { R.id.title,R.id.timelength });
listView.setAdapter(adapter);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
服务器端实现的代码如下：
实现请求的Servlet方法
public class ServletForXML extends HttpServlet {
private static final long serialVersionUID = 1L;
private XMLService newsService = new XMLServiceBean();
protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {
doPost(request,response);
}
protected void doPost(HttpServletRequest request,IOException {
List<News> newes = newsService.getLastNews();
request.setAttribute("newes",newes);
request.getRequestDispatcher("/WEB-INF/page/news.jsp").forward(request,response);
}
}实现bean的业务方法和添加测试数据的方法如下
public class XMLServiceBean implements XMLService {
@Override
public List<News> getLastNews() {
List<News> newes = new ArrayList<News>();
newes.add(new News(10,"wangjie",20));
newes.add(new News(45,"test",10));
newes.add(new News(89,"good",50));
return newes;
}
} 原文链接：https://www.f2er.com/xml/300528.html