Android异步XML解析
我试图从url解析XML并在listview上显示它。但是,listview正在显示 像这样 [我不能直接在这里发布任何图片,因为我的声誉低于10] 这是我的密码 main活动Android异步XML解析,android,xml,xml-parsing,android-asynctask,Android,Xml,Xml Parsing,Android Asynctask,我试图从url解析XML并在listview上显示它。但是,listview正在显示 像这样 [我不能直接在这里发布任何图片,因为我的声誉低于10] 这是我的密码 main活动 getRssDataTask ts = new getRssDataTask(); ts.execute("http://www.xyzapp.com/feed"); } private class getRssDataTask extends AsyncTask<String, Void, List
getRssDataTask ts = new getRssDataTask();
ts.execute("http://www.xyzapp.com/feed");
}
private class getRssDataTask extends AsyncTask<String, Void, List<NewsItem>>{
@Override
protected List<NewsItem> doInBackground(String... params) {
// TODO Auto-generated method stub
try {
// Create RSS reader
RSSReader rssReader = new RSSReader(params[0]);
// Parse RSS, get items
return rssReader.getItems();
} catch (Exception e) {
Log.e("App", e.getMessage());
}
return null;
}
@Override
protected void onPostExecute(List<NewsItem> result) {
ListView Items = (ListView) findViewById(R.id.listView);
// Create a list adapter
ArrayAdapter<NewsItem> rs = new ArrayAdapter<NewsItem>(local,android.R.layout.simple_list_item_1, result);
// Set list adapter for the ListView
Items.setAdapter(rs);
getRssDataTask ts=new getRssDataTask();
ts.execute(“http://www.xyzapp.com/feed");
}
私有类getRssDataTask扩展异步任务{
@凌驾
受保护列表doInBackground(字符串…参数){
//TODO自动生成的方法存根
试一试{
//创建RSS阅读器
RSSReader RSSReader=新RSSReader(参数[0]);
//解析RSS,获取项目
返回rssReader.getItems();
}捕获(例外e){
Log.e(“App”,e.getMessage());
}
返回null;
}
@凌驾
受保护的void onPostExecute(列表结果){
ListView项=(ListView)findViewById(R.id.ListView);
//创建一个列表适配器
ArrayAdapter rs=新的ArrayAdapter(本地,android.R.layout.simple_列表_项_1,结果);
//为ListView设置列表适配器
设置适配器(rs);
RssHandler
public class RssHandler extends DefaultHandler {
private List<NewsItem> rssItem;
private NewsItem currentItem;
private boolean parsingTitle;
private boolean parsingDes;
public RssHandler() {
// TODO Auto-generated constructor stub
rssItem = new ArrayList<NewsItem>();
}
public List<NewsItem> getItems() {
return rssItem;
}
@Override
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
// TODO Auto-generated method stub
if ("item".equals(qName)) {
currentItem = new NewsItem();
} else if ("title".equals(qName)) {
parsingTitle = true;
} else if ("content:encoded".equals(qName)) {
parsingDes = true;
}
}
@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
// TODO Auto-generated method stub
if ("item".equals(qName)) {
rssItem.add(currentItem);
currentItem = null;
} else if ("title".equals(qName)) {
parsingTitle = false;
} else if ("content:encoded".equals(qName)) {
parsingDes = false;
}
}
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
// TODO Auto-generated method stub
if (parsingTitle) {
if (currentItem != null)
currentItem.setTitle(new String(ch, start, length));
} else if (parsingDes) {
if (currentItem != null) {
currentItem.setDes(new String(ch, start, length));
parsingDes = false;
}
}
}
}
public class RSSReader {
private String RssUrl;
public RSSReader(String RssUrl) {
// TODO Auto-generated constructor stub
this.RssUrl = RssUrl;
}
public List<NewsItem> getItems() throws Exception{
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser saxParser = factory.newSAXParser();
RssHandler handler = new RssHandler();
saxParser.parse(RssUrl, handler);
return handler.getItems();
}
}
公共类RssHandler扩展了DefaultHandler{
私有列表rssItem;
私人新闻项目;
私有布尔parsingtile;
私有布尔parsingDes;
公共图书馆{
//TODO自动生成的构造函数存根
rssItem=newarraylist();
}
公共列表getItems(){
返回rssItem;
}
@凌驾
public void startElement(字符串uri、字符串localName、字符串qName、,
属性)引发SAX异常{
//TODO自动生成的方法存根
如果(“项”。等于(qName)){
currentItem=新新闻项();
}else if(“title.”等于(qName)){
parsingTitle=真;
}else if(“内容:编码”。等于(qName)){
帕辛德斯=真;
}
}
@凌驾
公共void endElement(字符串uri、字符串localName、字符串qName)
抛出SAX异常{
//TODO自动生成的方法存根
如果(“项”。等于(qName)){
rssItem.add(当前项);
currentItem=null;
}else if(“title.”等于(qName)){
parsingTitle=假;
}else if(“内容:编码”。等于(qName)){
帕辛德斯=假;
}
}
@凌驾
公共无效字符(字符[]ch,整数开始,整数长度)
抛出SAX异常{
//TODO自动生成的方法存根
if(parsingtille){
如果(currentItem!=null)
currentItem.setTitle(新字符串(ch,start,length));
}否则如果(帕辛德斯){
如果(currentItem!=null){
currentItem.setDes(新字符串(ch,start,length));
帕辛德斯=假;
}
}
}
}
RssReader
public class RssHandler extends DefaultHandler {
private List<NewsItem> rssItem;
private NewsItem currentItem;
private boolean parsingTitle;
private boolean parsingDes;
public RssHandler() {
// TODO Auto-generated constructor stub
rssItem = new ArrayList<NewsItem>();
}
public List<NewsItem> getItems() {
return rssItem;
}
@Override
public void startElement(String uri, String localName, String qName,
Attributes attributes) throws SAXException {
// TODO Auto-generated method stub
if ("item".equals(qName)) {
currentItem = new NewsItem();
} else if ("title".equals(qName)) {
parsingTitle = true;
} else if ("content:encoded".equals(qName)) {
parsingDes = true;
}
}
@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
// TODO Auto-generated method stub
if ("item".equals(qName)) {
rssItem.add(currentItem);
currentItem = null;
} else if ("title".equals(qName)) {
parsingTitle = false;
} else if ("content:encoded".equals(qName)) {
parsingDes = false;
}
}
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
// TODO Auto-generated method stub
if (parsingTitle) {
if (currentItem != null)
currentItem.setTitle(new String(ch, start, length));
} else if (parsingDes) {
if (currentItem != null) {
currentItem.setDes(new String(ch, start, length));
parsingDes = false;
}
}
}
}
public class RSSReader {
private String RssUrl;
public RSSReader(String RssUrl) {
// TODO Auto-generated constructor stub
this.RssUrl = RssUrl;
}
public List<NewsItem> getItems() throws Exception{
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser saxParser = factory.newSAXParser();
RssHandler handler = new RssHandler();
saxParser.parse(RssUrl, handler);
return handler.getItems();
}
}
公共类RSSReader{
私有字符串RssUrl;
公共RSSReader(字符串RssUrl){
//TODO自动生成的构造函数存根
this.RssUrl=RssUrl;
}
public List getItems()引发异常{
SAXParserFactory=SAXParserFactory.newInstance();
SAXParser SAXParser=factory.newSAXParser();
RssHandler handler=新的RssHandler();
parse(RssUrl,handler);
return handler.getItems();
}
}
我无法解决问题。我的问题是我做错了什么?在NewsItem中实现以下方法:
@Override
public String toString() {
// return a String value representing this object
// Assuming two class String properties called title and description
return title + ": " + description;
}
您需要重写
NewsItem
中的toString()
我有两个字符串标题和描述。如何同时返回两个字符串?已编辑的答案。假设您的类中有两个字符串属性。如何创建要返回的格式化字符串值取决于您自己。我使用了“:”字符来分隔这两个字符串