我有一个可以正常工作的 XML 解析器,但是如果用户连接到未浏览应用程序的网络就会中断。放一个功能来检测用户是否连接,但是上面提到的问题,用户会连接但不能浏览。
我的代码如下:
public void chamaParser(){
Boolean conected = Conectado(this);
if(conected == true){
new DoInBackground().execute();
} else {
mPullRefreshListViewRSS.onRefreshComplete();
new AlertDialog.Builder(PullToRefreshListActivityRSS.this)
.setTitle("Alerta!")
.setMessage("Não foi possível estabelecer uma conexão com a Internet, verifique sua rede ou tente novamente mais tarde.")
.setNeutralButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {}
}).show();
}
}
public void do_update() {
RssParser.parse();
}
public static boolean Conectado(Context context) {
try {
ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
String LogSync = null;
String LogToUserTitle = null;
if (cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).isConnected()) {
LogSync += "\nConectado a Internet 3G ";
LogToUserTitle += "Conectado a Internet 3G ";
return true;
} else if(cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnected()) {
LogSync += "\nConectado a Internet WIFI ";
LogToUserTitle += "Conectado a Internet WIFI ";
return true;
} else {
LogSync += "\nNão possui conexão com a internet ";
LogToUserTitle += "Não possui conexão com a internet ";
return false;
}
} catch (Exception e) {
return false;
}
}
private class DoInBackground extends AsyncTask<Void, Void, Void> implements DialogInterface.OnCancelListener {
private ProgressDialog dialog;
protected void onPreExecute() {
//dialog = ProgressDialog.show(PullToRefreshListActivityRSS.this, "", "Carregando...", true);
dialog = ProgressDialog.show(PullToRefreshListActivityRSS.this, "", "Carregando...", true, true, new DialogInterface.OnCancelListener(){
@Override
public void onCancel(DialogInterface dialog) {
mPullRefreshListViewRSS.onRefreshComplete();
DoInBackground.this.cancel(true);
// finish();
}
});
}
protected Void doInBackground(Void... unused) {
PodcastAdapterRSS.topBarRSS=true;
do_update();
return null;
}
解析器 XML:
public class RssParser {
public static void parse() {
URL url;
try {
url = new URL("http://www.xxxx.com.br/feed/");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
if(conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc;
doc = db.parse(url.openStream());
doc.getDocumentElement().normalize();
NodeList itemLst = doc.getElementsByTagName("item");
arrays.Title = new String[itemLst.getLength()];
arrays.Link = new String[itemLst.getLength()];
arrays.Description = new String[itemLst.getLength()];
// arrays.PodcastMedia = new String[itemLst.getLength()];
for(int i=0; i < itemLst.getLength(); i++){
Node item = itemLst.item(i);
if(item.getNodeType() == Node.ELEMENT_NODE){
Element ielem = (Element)item;
NodeList title = ielem.getElementsByTagName("title");
NodeList link = ielem.getElementsByTagName("link");
//NodeList description = ielem.getElementsByTagName("description");
NodeList content = ielem.getElementsByTagName("description");
// NodeList media = ielem.getElementsByTagName("media:content");
// String mediaurl = media.item(0).getAttributes().getNamedItem("url").getNodeValue();
arrays.Title[i] = title.item(0).getChildNodes().item(0).getNodeValue();
arrays.Link[i] = link.item(0).getChildNodes().item(0).getNodeValue();
arrays.Description[i] = content.item(0).getChildNodes().item(0).getNodeValue();
}
}
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (DOMException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
原木猫:
07-30 15:20:48.319: W/System.err(10997): java.net.UnknownHostException: www.xxxx.com.br 07-30 15:20:48.319: W/System.err(10997): 在java.net.InetAddress.lookupHostByName(InetAddress.java:508) 07-30 15:20:48.319: W/System.err(10997): 在 java.net.InetAddress.getAllByNameImpl(InetAddress.java:296) 07-30 15:20:48.319: W/System.err(10997): 在 java.net.InetAddress.getAllByName(InetAddress.java:258) 07-30 15:20:48.319: W/System.err(10997): 在 org .apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.(HttpConnection.java:69) 07-30 15:20:48.319: W/System.err(10997): at org.apache.harmony .luni.internal.net.www.protocol.http.HttpConnection.(HttpConnection.java:48) 07-30 15:20:48.319: W/System.err(10997): at org.apache.harmony.luni.internal .net.www.protocol.http.HttpConnection$Address.connect(HttpConnection.java:322) 07-30 15:20:48.319: W/System.err(10997): 在 org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:89 ) 07-30 15:20:48.319: W/System.err(10997): 在 org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:285) 07- 30 15:20:48.319: W/System.err(10997): 在 org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:267) 07-30 15: 20:48.319: W/System.err(10997): 在 org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.retrieveResponse(HttpURLConnectionImpl.java:1018) 07-30 15:20:48.319 : W/System.err(10997): 在 org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:726) 07-30 15:20:48.329: W/System.err(10997): 在 tabbar.rss.RssParser.parse(RssParser.java:30) 07-30 15:20:48.329: W/System.err( 10997): 在 tabbar.rss.PullToRefreshListActivityRSS.do_update(PullToRefreshListActivityRSS.java:91) 07-30 15:20:48.329: W/System.err(10997): 在 tabbar.rss.PullToRefreshListActivityRSS$DoInBackground.doInBackground(PullToRefreshListActivityRSS.java :205) 07-30 15:20:48.329: W/System.err(10997): 在 tabbar.rss.PullToRefreshListActivityRSS$DoInBackground.doInBackground(PullToRefreshListActivityRSS.java:1) 07-30 15:20:48.329: W/System .err(10997): 在 android.os.AsyncTask$2.call(AsyncTask.java:185) 07-30 15:20:48.329: W/System.err(10997): 在 java.util.concurrent.FutureTask$Sync .innerRun(FutureTask.java:306) 07-30 15:20:48.329: W/System.err(10997): 在 java.util.concurrent.FutureTask.run(FutureTask.java:138) 07-30 15:20:48.329: W/System.err(10997): 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) 07-30 15:20:48.329: W/ System.err(10997): 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) 07-30 15:20:48.329: W/System.err(10997): 在 java.lang.Thread .run(Thread.java:1019) 07-30 15:20:48.329: W/dalvikvm(10997): threadid=1: 线程以未捕获的异常退出 (group=0x401fc560) 07-30 15:20:48.339: E/ AndroidRuntime(10997):致命异常:主要 07-30 15:20:48.339:E/AndroidRuntime(10997):java.lang.NullPointerException 07-30 15:20:48.339:E/AndroidRuntime(10997):在 tabbar.rss .PullToRefreshListActivityRSS.populate_listview(PullToRefreshListActivityRSS.java:101) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 tabbar.rss。PullToRefreshListActivityRSS$DoInBackground.onPostExecute(PullToRefreshListActivityRSS.java:214) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 tabbar.rss.PullToRefreshListActivityRSS$DoInBackground.onPostExecute(PullToRefreshListActivityRSS.java:1) 07-30 15: 20:48.339: E/AndroidRuntime(10997): 在 android.os.AsyncTask.finish(AsyncTask.java:417) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 android.os.AsyncTask.access $300(AsyncTask.java:127) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 android.os.Handler.dispatchMessage(Handler.java:99) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 android.os.Looper.loop(Looper.java :130) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 android.app。ActivityThread.main(ActivityThread.java:3689) 07-30 15:20:48.339: E/AndroidRuntime(10997): at java.lang.reflect.Method.invokeNative(Native Method) 07-30 15:20:48.339: E /AndroidRuntime(10997): at java.lang.reflect.Method.invoke(Method.java:507) 07-30 15:20:48.339: E/AndroidRuntime(10997): at com.android.internal.os.ZygoteInit$ MethodAndArgsCaller.run(ZygoteInit.java:875) 07-30 15:20:48.339: E/AndroidRuntime(10997): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:633) 07-30 15: 20:48.339:E/AndroidRuntime(10997):在 dalvik.system.NativeStart.main(本机方法)507) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:875) 07-30 15:20:48.339: E/ AndroidRuntime(10997): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:633) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 dalvik.system.NativeStart.main(Native方法)507) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:875) 07-30 15:20:48.339: E/ AndroidRuntime(10997): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:633) 07-30 15:20:48.339: E/AndroidRuntime(10997): 在 dalvik.system.NativeStart.main(Native方法)