我正在尝试使用这个RSS parsing library实现非常简单的RSS解析器。根据实现，我只需粘贴提供的示例代码，一旦我将代码作为库导入。
我采取的步骤：
是因为图书馆很旧吗？我做错了什么吗？非常感谢任何帮助。
代码：
package com.example.rssparser;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import org.xml.sax.SAXException;
import nl.matshofman.saxrssreader.RssFeed;
import nl.matshofman.saxrssreader.RssItem;
import nl.matshofman.saxrssreader.RssReader;
import android.app.Activity;
import android.os.Bundle;
//import android.util.Log;
import android.view.Menu;
import android.widget.TextView;
public class MainActivity extends Activity {
TextView rss_feed_data;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
URL url;
try {
url = new URL("http://wwwnc.cdc.gov/travel/rss/notices.xml");
RssFeed feed;
try {
feed = RssReader.read(url);
ArrayList<RssItem> rssItems = feed.getRssItems();
for(RssItem rssItem : rssItems) {
//Log.i("RSS Reader", rssItem.getTitle());
rss_feed_data = (TextView) findViewById(R.id.rss_feed_data);
rss_feed_data.setText(rssItem.getTitle());
}
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
LOGCAT OUTPUT：
11-20 04:01:36.901: E/Trace(16331): error opening trace file: No such file or directory (2)
11-20 04:01:37.088: W/dalvikvm(16331): threadid=1: thread exiting with uncaught exception (group=0x41269908)
11-20 04:01:37.138: E/AndroidRuntime(16331): FATAL EXCEPTION: main
11-20 04:01:37.138: E/AndroidRuntime(16331): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rssparser/com.example.rssparser.MainActivity}: android.os.NetworkOnMainThreadException
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2234)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.ActivityThread.access$600(ActivityThread.java:181)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1332)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.os.Handler.dispatchMessage(Handler.java:99)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.os.Looper.loop(Looper.java:153)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.ActivityThread.main(ActivityThread.java:5037)
11-20 04:01:37.138: E/AndroidRuntime(16331): at java.lang.reflect.Method.invokeNative(Native Method)
11-20 04:01:37.138: E/AndroidRuntime(16331): at java.lang.reflect.Method.invoke(Method.java:511)
11-20 04:01:37.138: E/AndroidRuntime(16331): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825)
11-20 04:01:37.138: E/AndroidRuntime(16331): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:588)
11-20 04:01:37.138: E/AndroidRuntime(16331): at dalvik.system.NativeStart.main(Native Method)
11-20 04:01:37.138: E/AndroidRuntime(16331): Caused by: android.os.NetworkOnMainThreadException
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1125)
11-20 04:01:37.138: E/AndroidRuntime(16331): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
11-20 04:01:37.138: E/AndroidRuntime(16331): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
11-20 04:01:37.138: E/AndroidRuntime(16331): at java.net.InetAddress.getAllByName(InetAddress.java:214)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:292)
11-20 04:01:37.138: E/AndroidRuntime(16331): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:185)
11-20 04:01:37.138: E/AndroidRuntime(16331): at java.net.URL.openStream(URL.java:462)
11-20 04:01:37.138: E/AndroidRuntime(16331): at nl.matshofman.saxrssreader.RssReader.read(RssReader.java:35)
11-20 04:01:37.138: E/AndroidRuntime(16331): at com.example.rssparser.MainActivity.onCreate(MainActivity.java:29)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.Activity.performCreate(Activity.java:5020)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
11-20 04:01:37.138: E/AndroidRuntime(16331): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2198)
11-20 04:01:37.138: E/AndroidRuntime(16331): ... 11 more
更新代码
package com.example.rssparser;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import nl.matshofman.saxrssreader.RssFeed;
import nl.matshofman.saxrssreader.RssItem;
import nl.matshofman.saxrssreader.RssReader;
import org.xml.sax.SAXException;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.widget.TextView;
//import android.util.Log;
public class MainActivity extends Activity {
TextView rss_feed_data;
String ur = "http://wwwnc.cdc.gov/travel/rss/notices.xml";
ProgressDialog pDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rss_feed_data = (TextView) findViewById(R.id.rss_feed_data);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
new XmlParsing(ur).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, new String[]{null});
else
new XmlParsing(ur).execute(new String[]{null});
}
public class XmlParsing extends AsyncTask<String, String, ArrayList<RssItem>> {
// variables passed in:
String urls;
// constructor
public XmlParsing(String urls) {
this.urls = urls;
}
@Override
protected void onPreExecute() {
pDialog = ProgressDialog.show(MainActivity.this, "Fetching Details..", "Please wait...", true);
}
@Override
protected ArrayList<RssItem> doInBackground(String... params) {
// TODO Auto-generated method stub
URL url;
try {
url = new URL(urls);
RssFeed feed;
try {
feed = RssReader.read(url);
ArrayList<RssItem> rssItems = feed.getRssItems();
return rssItems;
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace(); }
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String result, ArrayList<RssItem> rssItems) {
// Now we have your JSONObject, play around with it.
if (pDialog.isShowing())
pDialog.dismiss();
for(RssItem rssItem : rssItems) {
//Log.i("RSS Reader", rssItem.getTitle());
rss_feed_data.setText(rssItem.getTitle());
}
}
}
}
LOGCAT输出
11-20 05:36:50.439: I/SurfaceTextureClient(17281): [STC::queueBuffer] this:0x516a20a8, api:1, last queue time elapsed :9510 ms
11-20 05:36:50.441: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:10.505000, fps:6.282219
11-20 05:36:50.473: I/SurfaceTextureClient(17281): [STC::queueBuffer] this:0x51655180, api:1, last queue time elapsed :131816 ms
11-20 05:36:50.494: I/SurfaceTextureClient(17281): [0x51655180] frames:1, duration:131.815994, fps:0.007586
11-20 05:36:51.426: I/SurfaceTextureClient(17281): [0x516a20a8] frames:45, duration:1.016000, fps:44.289616
11-20 05:36:52.437: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.010000, fps:65.308807
11-20 05:36:53.449: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.012000, fps:65.186592
11-20 05:36:54.462: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.012000, fps:65.197708
11-20 05:36:55.474: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.012000, fps:65.203377
11-20 05:36:56.486: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.012000, fps:65.198250
11-20 05:36:57.498: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.012000, fps:65.211411
11-20 05:36:58.509: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.010000, fps:65.283676
11-20 05:36:59.520: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.010000, fps:65.318069
11-20 05:37:00.530: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.010000, fps:65.322647
11-20 05:37:01.542: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.240547
11-20 05:37:02.556: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.244469
11-20 05:37:03.565: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.245308
11-20 05:37:04.577: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.252708
11-20 05:37:05.588: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.248543
11-20 05:37:06.600: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.246178
11-20 05:37:07.611: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.253662
11-20 05:37:08.622: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.253265
11-20 05:37:09.634: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.248100
11-20 05:37:10.646: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.222153
11-20 05:37:11.656: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.010000, fps:65.313301
11-20 05:37:12.667: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.010000, fps:65.318176
11-20 05:37:13.678: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.267540
11-20 05:37:14.689: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.262505
11-20 05:37:15.701: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.258896
11-20 05:37:16.712: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.275986
11-20 05:37:17.723: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.265404
11-20 05:37:18.734: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.277664
11-20 05:37:19.745: I/SurfaceTextureClient(17281): [0x516a20a8] frames:66, duration:1.011000, fps:65.250298
答案 0 :(得分：1)
当应用程序尝试在其主线程上执行网络操作时，会抛出此异常。在AsyncTask中运行您的代码：
public class MainActivity extends Activity {
TextView rss_feed_data;
String ur = "http://wwwnc.cdc.gov/travel/rss/notices.xml";
ProgressDialog pDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rss_feed_data = (TextView) findViewById(R.id.rss_feed_data);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
new XmlParsing(ur).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, new String[]{null});
else
new XmlParsing(ur).execute(new String[]{null});
}
public class XmlParsing extends AsyncTask<String, String, ArrayList<RssItem>> {
// variables passed in:
String urls;
// constructor
public XmlParsing(String urls) {
this.urls = urls;
}
@Override
protected void onPreExecute() {
pDialog = ProgressDialog.show(NetActivity.this, "Fetching Details..", "Please wait...", true);
}
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
URL url;
try {
url = new URL();
RssFeed feed;
try {
feed = RssReader.read(url);
ArrayList<RssItem> rssItems = feed.getRssItems();
return rssItems;
}
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result) {
// Now we have your JSONObject, play around with it.
if (pDialog.isShowing())
pDialog.dismiss();
for(RssItem rssItem : rssItems) {
//Log.i("RSS Reader", rssItem.getTitle());
rss_feed_data.setText(rssItem.getTitle());
}
}