我知道这种问题不容易解决，因为可能是一切的原因。无论如何我试着解释..我有一个Listview解析网页中的一些标签..我需要的信息是：页面中每篇文章的位图，标题，描述以及文章发布的时间。一切顺利，但有时，随机，我收到一个错误，日志是：
02-17 15:41:13.852: E/ESEMPIO(24448): ERRORE NEL PARSING
02-17 15:41:17.192: E/AndroidRuntime(24448): FATAL EXCEPTION: main
02-17 15:41:17.192: E/AndroidRuntime(24448): Process: it.dd.multiplayerit, PID: 24448
02-17 15:41:17.192: E/AndroidRuntime(24448): java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
02-17 15:41:17.192: E/AndroidRuntime(24448): at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
02-17 15:41:17.192: E/AndroidRuntime(24448): at java.util.ArrayList.get(ArrayList.java:308)
02-17 15:41:17.192: E/AndroidRuntime(24448): at it.dd.multiplayerit.ParsingArrayAdapter.getView(ParsingArrayAdapter.java:120)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.AbsListView.obtainView(AbsListView.java:2263)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.ListView.makeAndAddView(ListView.java:1790)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.ListView.fillDown(ListView.java:691)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.ListView.fillFromTop(ListView.java:752)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.ListView.layoutChildren(ListView.java:1630)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.AbsListView.onLayout(AbsListView.java:2091)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.View.layout(View.java:14824)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewGroup.layout(ViewGroup.java:4631)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.View.layout(View.java:14824)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewGroup.layout(ViewGroup.java:4631)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.View.layout(View.java:14824)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewGroup.layout(ViewGroup.java:4631)
02-17 15:41:17.192: E/AndroidRuntime(24448): at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.View.layout(View.java:14824)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewGroup.layout(ViewGroup.java:4631)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.View.layout(View.java:14824)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewGroup.layout(ViewGroup.java:4631)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1987)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1744)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.Choreographer.doCallbacks(Choreographer.java:574)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.Choreographer.doFrame(Choreographer.java:544)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.os.Handler.handleCallback(Handler.java:733)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.os.Handler.dispatchMessage(Handler.java:95)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.os.Looper.loop(Looper.java:136)
02-17 15:41:17.192: E/AndroidRuntime(24448): at android.app.ActivityThread.main(ActivityThread.java:5081)
02-17 15:41:17.192: E/AndroidRuntime(24448): at java.lang.reflect.Method.invoke(Native Method)
02-17 15:41:17.192: E/AndroidRuntime(24448): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:781)
02-17 15:41:17.192: E/AndroidRuntime(24448): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
在ParsingArrayAdapter的第120行，我有这一行：
cache.immagini.setImageBitmap(bitmap.get(pos));
要让我需要的所有值首先解析标题，描述和日期..然后是位图。这是MainActivity中的代码，其中我填充了listview
private class ParsingPaginaWeb extends AsyncTask<String,String,String> {
//ArrayList<Bitmap> bitmap = new ArrayList<Bitmap>();
//ArrayList<String> content; //lista delle descrizioni
@Override
protected void onPreExecute()
{
//prima di eseguire il parsing inizializzo gli arraylist
titoli = new ArrayList<String>();
bitmap = new ArrayList<Bitmap>();
data = new ArrayList<String>();
categoria = new ArrayList<String>();
//content = new ArrayList<String>();
}
@Override
protected String doInBackground(String... params) {
try {
Document doc = Jsoup.connect(BLOG_URL)
.get();
Elements sezioni = doc.getElementsByClass("archive_box");
for (Element riga : sezioni) {
Element info = riga.getElementsByClass("text").first();
String titolo = riga.getElementsByTag("h2").first().text();
System.out.println(titolo);
titoli.add(titolo);
String date = info.getElementsByClass("date").first().text();
System.out.println(date);
data.add(date);
// categoria
String category = info.getElementsByClass("category").first().text();
System.out.println(category);
categoria.add(category);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result)
{
new Logo().execute();
}
// for bitmap
// Logo AsyncTask
private class Logo extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = new ProgressDialog(MainActivity.this);
mProgressDialog.setTitle("Multiplayer.it");
mProgressDialog.setMessage("Caricamento articoli...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
mProgressDialog.setCanceledOnTouchOutside(false);
}
@Override
protected Void doInBackground(Void... params) {
try {
// Connect to the web site
Document document = Jsoup.connect(BLOG_URL).get();
// Using Elements to get the class data
// Locate the src attribute
for(Element img : document.select("div.col-1-1 img[src]")) {
String ImgSrc = img.attr("src");
// Download image from URL
InputStream is = new java.net.URL(ImgSrc).openStream();
//add Bitmap to an array
bitmap.add(BitmapFactory.decodeStream(is));
}
} catch (IOException e) {
e.printStackTrace();
Log.e("ESEMPIO", "ERRORE NEL PARSING DELLE IMMAGINI");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
// Set downloaded image into ImageView
// Controllo se bitmap è nullo
if (bitmap!=null){
Log.d("Bitmap MP.it", "BitmapNOTnull");
}else{
Log.d("Bitmap null MP.it", "Bitmapnull");
}
// Check if titoli is empty
if (titoli.isEmpty()){
Log.d("Array empty"empty");
}
logoimg = (ImageView) findViewById(R.id.imageView1);
mProgressDialog.dismiss();
ParsingArrayAdapter adapter = new ParsingArrayAdapter(MainActivity.this, titoli, bitmap, data, categoria);
lista.setAdapter(adapter);
}
}
哪里可能是问题？
使用适配器编辑
public class ParsingArrayAdapter extends ArrayAdapter<String>{
//riferimenti statici alle risorse e agli id
private final static int LAYOUT = R.layout.riga_listview;
private final static int TITOLO = R.id.riga_listview_titolo;
private final static int DATA = R.id.riga_listview_data;
private final static int CATEGORIA = R.id.riga_listview_categoria;
private final static int IMMAGINE = R.id.imageView1;
//links
// private final static int LINKS = R.id.riga_listview_links;
ArrayList<Bitmap> bitmap;
ArrayList<String> links;
ArrayList<String> titoli; //lista dei titoli
ArrayList<String> data; //lista delle date
ArrayList<String> categoria; //lista delle categorie
Context c; //context
LayoutInflater inflater; //layout inflater
//ImageLoader imageLoader=new ImageLoader(ParsingArrayAdapter.getApplicationContext());
public ParsingArrayAdapter(Context context,ArrayList<String> titoli, ArrayList<Bitmap> bitmap, ArrayList<String> data, ArrayList<String> categoria)
{
super(context,TITOLO);
this.c = context;
this.titoli = titoli;
//this.links = links;
this.data = data;
this.categoria = categoria;
this.bitmap = bitmap;
this.inflater = LayoutInflater.from(c);
if (this.titoli.size() > this.bitmap.size()){
Log.d("Array compare", "Titoli > Bitmap!"+ " " + titoli.size() + " " + bitmap.size());
titoli.remove(titoli.size() - 1);
}
if (this.titoli.size() == this.bitmap.size())
Log.d("Array compare", "Titoli = Bitmap!" + " " + titoli.size() + " " + bitmap.size());
if (this.titoli.size() > this.data.size())
Log.d("Array compare", "Titoli > Data!"+ " " + titoli.size() + " " + data.size());
if (this.titoli.size() == this.data.size())
Log.d("Array compare", "Titoli = Bitmap!" + " " + titoli.size() + " " + data.size());
}
@Override
public int getCount()
{
return titoli.size();
//return bitmap.size();//ritorno lunghezza lista ( = numero dei titoli)
}
//quando la lista richiede una view
@SuppressLint("NewApi")
@Override
public View getView(int pos,View view,ViewGroup parent)
{
CacheRiga cache; //cache
if(view==null)//se è la prima volta che viene richiesta la view
{
// creo la view ma non l'attacco alla lista in quanto devo ancora modificare
// i testi delle textview
view = inflater.inflate(LAYOUT, parent,false);
cache = new CacheRiga(); //inizializzo la cache
cache.titolo = (TextView) view.findViewById(TITOLO); //collego titolo
cache.dateArticoli = (TextView) view.findViewById(DATA); //collego la data
cache.categoriatext = (TextView) view.findViewById(CATEGORIA); //collego la data
//cache.linkstext = (TextView) view.findViewById(LINKS); //collego la data
cache.immagini = (ImageView) view.findViewById(IMMAGINE);//collego descrizione
view.setTag(cache);//collego view con cache
}
else
{
cache = (CacheRiga) view.getTag(); //altrimenti prendo la cache dalla view
}
if (this.titoli.size() > 0 && pos < this.titoli.size()){
cache.titolo.setText(titoli.get(pos)); //imposto il titolo
}
/*if (this.links.size() > 0 && pos < this.links.size()){
cache.linkstext.setText(links.get(pos)); //imposto il titolo
}*/
if (this.data.size() > 0 && pos < this.data.size()){
cache.dateArticoli.setText(data.get(pos));
}
cache.categoriatext.setText(categoria.get(pos));
cache.immagini.setImageBitmap(bitmap.get(pos));
//ImageView iv = (ImageView) view.findViewById(IMMAGINE);
//iv.setImageBitmap(getItem(pos));
if (bitmap!=null){
Log.d("Bitmap MP.it", "BitmapNOTnull");
}else{
Log.d("Bitmap null MP.it", "Bitmapnull");
}
if (data!=null){
Log.d("Data", "Data NOT null");
}else{
Log.d("Data", "Data null");
}
return view;
}
private class CacheRiga { // classe per la cache delle righe
public TextView titolo; // cache titolo
public TextView dateArticoli; // cache data
public TextView categoriatext; // cache categoria
//public TextView linkstext;
public ImageView immagini; // cache descrizione
}