我正在尝试创建一个读取Rss Feed的RSS阅读器，并将其显示在列表视图中。我得到了他的其他RSS源，但我不能让它在我真正需要它的Feed上工作。我验证了Feed，它说它是一个没有错误的有效RSS源。我知道问题/解决方案在getDomFromXMLString方法中，它实际上是将XML拉入其中，但我无法弄清楚如何使其正确读取。
这是我的主要活动
package com.example.lehi.events;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends Activity {
String key_items = "item";
String key_title = "title";
String key_description = "description";
String key_link = "link";
String key_date = "pubDate";
ListView lstPost = null;
List<HashMap<String, Object>> post_lists = new ArrayList<HashMap<String, Object>>();
List<String> lists = new ArrayList<String>();
ArrayAdapter<String> adapter = null;
RSSReader rssfeed = new RSSReader();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lstPost = (ListView) findViewById(R.id.lstPosts);
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_2, android.R.id.text1, lists) {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView txt1 = (TextView) view
.findViewById(android.R.id.text1);
TextView txt2 = (TextView) view
.findViewById(android.R.id.text2);
HashMap<String, Object> data = post_lists.get(position);
txt1.setText(data.get(key_title).toString());
txt2.setText(data.get(key_description).toString());
return view;
}
};
Document xmlFeed;
xmlFeed = rssfeed.getRSSFromServer("http://calendar.byui.edu/RSSFeeds.aspx?data=hhAbVFpDFO7OxcTcYlM9Lk3inbX%2bJ%2baS3fubTE468TQI91kccS33vQ%3d%3d");
NodeList nodes = xmlFeed.getElementsByTagName("item");
for (int i = 0; i < nodes.getLength(); i++) {
Element item = (Element) nodes.item(i);
HashMap<String, Object> feed = new HashMap<String, Object>();
feed.put(key_title, rssfeed.getValue(item, key_title));
feed.put(key_description, rssfeed.getValue(item, key_description));
feed.put(key_link, rssfeed.getValue(item, key_link));
feed.put(key_date, rssfeed.getValue(item, key_date));
post_lists.add(feed);
lists.add(feed.get(key_title).toString());
}
lstPost.setAdapter(adapter);
}
}
由于
编辑： 这是rssfeed被声明为的对象。
import java.io.StringReader;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import android.os.StrictMode;
public class RSSReader {
DefaultHttpClient httpClient = new DefaultHttpClient();
public Document getRSSFromServer(String url) {
Document response = null;
response = getDomFromXMLString(getFeedFromServer(url));
return response;
}
private String getFeedFromServer(String url) {
String xml = null;
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
}
try {
HttpGet httpget =new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpget);
HttpEntity httpEntity = httpResponse.getEntity();
xml = EntityUtils.toString(httpEntity);
} catch (Exception e) {
e.printStackTrace();
}
return xml;
}
private Document getDomFromXMLString(String xml) {
Document doc = null;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = dbf.newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(xml));
doc = db.parse(is);
} catch (Exception e) {
}
return doc;
}
public String getValue(Element item, String key) {
NodeList nodeList = item.getElementsByTagName(key);
return this.getElementValue(nodeList.item(0));
}
public final String getElementValue(Node node) {
Node child;
if (node != null) {
if (node.hasChildNodes()) {
for (child = node.getFirstChild(); child != null; child = child
.getNextSibling()) {
if (child.getNodeType() == Node.TEXT_NODE) {
return child.getNodeValue();
}
}
}
}
return "";
}
}
我想弄明白org.xml.sax.SAXParseException: Unexpected token (position:TEXT @1:4 in java.io.StringReader@19916b6d)。
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ org.xml.sax.SAXParseException: Unexpected token (position:TEXT @1:4 in java.io.StringReader@19916b6d)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at org.apache.harmony.xml.parsers.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:146)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at com.example.lehi.events.RSSReader.getDomFromXMLString(RSSReader.java:58)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at com.example.lehi.events.RSSReader.getRSSFromServer(RSSReader.java:29)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at com.example.lehi.events.MainActivity.onCreate(MainActivity.java:56)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.app.Activity.performCreate(Activity.java:5933)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.app.ActivityThread.access$800(ActivityThread.java:144)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:102)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.os.Looper.loop(Looper.java:135)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5221)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at java.lang.reflect.Method.invoke(Native Method)
03-15 18:29:08.307 3612-3612/com.example.lehi.events W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:372)
03-15 18:29:08.308 3612-3612/com.example.lehi.events W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
03-15 18:29:08.308 3612-3612/com.example.lehi.events W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
答案 0 :(得分：0)
如果getDomFromXMLString中有例外，请尝试打印堆栈跟踪。我猜有一个例外，目前正在被吞并，然后返回的Document就是null。
编辑：现在我们看到了SAXParseException: Unexpected token 。那是UTF-8字节顺序标记。试试EntityUtils.toString(httpEntity, "UTF-8")，看看是否有助于吞下BOM。