我是Android开发应用程序的新手，我想将rss url解析为listview。代码正在运行但我们想从rss提取中提取图像并将其显示在列表视图中。
RssItem.java
public class RssItem {
// item title
private String title;
// item link
private String link;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getLink() {
return link;
}
public void setLink(String link) {
this.link = link;
}
@Override
public String toString() {
return title;
}
}
ListListener.java
public class ListListener implements OnItemClickListener {
// List item's reference
List<RssItem> listItems;
// Calling activity reference
Activity activity;
public ListListener(List<RssItem> aListItems, Activity anActivity) {
listItems = aListItems;
activity = anActivity;
}
/**
* Start a browser with url from the rss item.
*/
public void onItemClick(AdapterView<?> parent, View view, int pos, long id) {
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(listItems.get(pos).getLink()));
activity.startActivity(i);
}
}
RssParseHandler.java
public class RssParseHandler extends DefaultHandler {
private List<RssItem> rssItems;
// Used to reference item while parsing
private RssItem currentItem;
// Parsing title indicator
private boolean parsingTitle;
// Parsing link indicator
private boolean parsingLink;
public RssParseHandler() {
rssItems = new ArrayList<RssItem>();
}
public List<RssItem> getItems() {
return rssItems;
}
@Override
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException
{
if ("item".equals(qName)) {
currentItem = new RssItem();
} else if ("title".equals(qName)) {
parsingTitle = true;
} else if ("link".equals(qName)) {
parsingLink = true;
}
}
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
if ("item".equals(qName)) {
rssItems.add(currentItem);
currentItem = null;
} else if ("title".equals(qName)) {
parsingTitle = false;
} else if ("link".equals(qName)) {
parsingLink = false;
}
}
@Override
public void characters(char[] ch, int start, int length) throws SAXException {
if (parsingTitle) {
if (currentItem != null)
currentItem.setTitle(new String(ch, start, length));
} else if (parsingLink) {
if (currentItem != null) {
currentItem.setLink(new String(ch, start, length));
parsingLink = false;
}
}
}
}
RssReader.java
public class RssReader {
private String rssUrl;
/**
* Constructor
*
* @param rssUrl
*/
public RssReader(String rssUrl) {
this.rssUrl = rssUrl;
}
/**
* Get RSS items.
*
* @return
*/
public List<RssItem> getItems() throws Exception {
// SAX parse RSS data
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser saxParser = factory.newSAXParser();
RssParseHandler handler = new RssParseHandler();
saxParser.parse(rssUrl, handler);
return handler.getItems();
}
}
ITCutiesReaderAppActivity.java
public class ITCutiesReaderAppActivity extends Activity {
// A reference to the local object
private ITCutiesReaderAppActivity local;
/**
* This method creates main application view
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set view
setContentView(R.layout.main);
// Set reference to this activity
local = this;
GetRSSDataTask task = new GetRSSDataTask();
// Start download RSS task
task.execute("http://www.itcuties.com/feed/#sthash.YI6YrEet.dpuf");
// Debug the thread name
Log.d("ITCRssReader", Thread.currentThread().getName());
}
public class GetRSSDataTask extends AsyncTask<String, Void, List<RssItem> > {
@Override
protected List<RssItem> doInBackground(String... urls) {
// Debug the task thread name
Log.d("ITCRssReader", Thread.currentThread().getName());
try {
// Create RSS reader
RssReader rssReader = new RssReader(urls[0]);
// Parse RSS, get items
return rssReader.getItems();
} catch (Exception e) {
Log.e("ITCRssReader", e.getMessage());
}
return null;
}
@Override
protected void onPostExecute(List<RssItem> result) {
// Get a ListView from main view
ListView itcItems = (ListView) findViewById(R.id.listMainView1);
// Create a list adapter
ArrayAdapter<RssItem> adapter = new ArrayAdapter<RssItem> (local,android.R.layout.simple_list_item_1, result);
// Set list adapter for the ListView
itcItems.setAdapter(adapter);
// Set list view item click listener
itcItems.setOnItemClickListener(new ListListener(result, local));
}
}
}
答案 0 :(得分：2)
在线阅读了几个小时后，我得到了这个，最初代码没有解析图像，但在阅读了DOM元素的文档后（从Android Studio附带的文档中），我能够创建以下内容实际上有效的代码片段。我在控制台中测试了它。
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
/**
* Created by user on 7/1/2016.
*/
public class FeedParser {
// names of the XML tags
static final String PUB_DATE = "pubDate";
static final String LINK = "link";
static final String TITLE = "title";
static final String ITEM = "item";
static final String IMAGE = "media:thumbnail";
static final String AUTHOR = "author";
final URL feedUrl;
public FeedParser(String feedUrl){
try {
this.feedUrl = new URL(feedUrl);
} catch (MalformedURLException e) {
throw new RuntimeException(e);
}
}
public InputStream getInputStream() {
try {
return feedUrl.openConnection().getInputStream();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public void parse() {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder builder = factory.newDocumentBuilder();
Document dom = builder.parse(this.getInputStream());
Element root = dom.getDocumentElement();
NodeList items = root.getElementsByTagName(ITEM);
for (int i=0;i<items.getLength();i++){
Node item = items.item(i);
NodeList properties = item.getChildNodes();
for (int j=0;j<properties.getLength();j++){
Node property = properties.item(j);
String name = property.getNodeName();
if (name.equalsIgnoreCase(TITLE)){
System.out.println(property.getFirstChild().getNodeValue());
} else if (name.equalsIgnoreCase(LINK)){
System.out.println(property.getFirstChild().getNodeValue());
} else if (name.equalsIgnoreCase(AUTHOR)){
StringBuilder text = new StringBuilder();
NodeList chars = property.getChildNodes();
for (int k=0;k<chars.getLength();k++){
text.append(chars.item(k).getNodeValue());
}
System.out.println(text.toString());
} else if (name.equalsIgnoreCase(PUB_DATE)){
System.out.println(property.getFirstChild().getNodeValue());
}
else if (name.equalsIgnoreCase(IMAGE)){
System.out.println(property.getAttributes().getNamedItem("url").getNodeValue());
}
}
}
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public static void main(String[] aeg){
new FeedParser("http://www.pcworld.com/index.rss").parse();
}
}
虽然我的回答很晚，但我希望它可以帮助其他人
答案 1 :(得分：1)
你正在重新发明轮子。您可以使用android-rss库droidQuery（最初发布here）来简化所有内容：
final RSSHandler handler = new RSSHandler(new RSSConfig());
$.ajax(new AjaxOptions().url(options.url())
.type("GET")
.dataType("XML")
.context(this)
.SAXContentHandler(handler)
.success(new Function() {
@Override
public void invoke($ droidQuery, Object... params) {
RSSFeed feed = handler.feed();
List<RSSItem> = feed.getItems();
//use this list to update your list adapter, then call the method "getThumbnails()" to get the images associated with the feed item.
}
}));