public class MainActivity extends AppCompatActivity {

ListView LVS. 
Map Map3; 
List & gt; Itmes=new ArrayList<> (a); 
Private List NewsList=new ArrayList<> (a); 


@ Override 
Protected void onCreate (Bundle savedInstanceState) {
Super. OnCreate (savedInstanceState); 
setContentView(R.layout.activity_main); 
The LVS=MainActivity. Enclosing the findViewById (R.i d.l v);//get the ListView control 
NewsAdapter adapter=new NewsAdapter (MainActivity. This, R.l ayout. Lv2, newsList); 
/* ListView ListView=the findViewById (R.i d.l v); 
ListView. SetAdapter (adapter); */
BTN (); 
} 

//defines methods button click on the button for the selected url assigned to download () method 
Public static String url; 
Public void BTN () {//domestic news (by default) 
Itmes. The clear (); 
Url="http://www.people.com.cn/rss/politics.xml"; 
The download (); 

}; 
Public void btn1 (View View) {//domestic news 
Itmes. The clear (); 
Url="http://www.people.com.cn/rss/politics.xml"; 
The download (); 

}; 
Public void btn2 View (View) {//sports news 
Itmes. The clear (); 
Url="http://www.people.com.cn/rss/sports.xml"; 
The download (); 
//"http://www.people.com.cn/rss/haixia.xml" 
}; 
Public void btn3 View (View) {//Taiwan news 
Itmes. The clear (); 
Url="http://www.people.com.cn/rss/haixia.xml"; 
The download (); 

}; 


Handler Handler=new Handler () {//to create an Android message processing mechanism to rewrite handleMessage method 
@ Override 
Public void handleMessage (Message MSG) {//process the Message, the method of using handleMessage to process the Message, the inside of the parameter Message 
//the message object can accept any type of object and can be through a reverse casts back 
String title=((News) MSG. Obj). GetTitle (); 
A String for its pubDate=((News) MSG. Obj). GetPubDate (); 
String author=((News) MSG. Obj). GetAuthor (); 
A String description=((News) MSG. Obj). The getDescription (); 

Map3=new HashMap<> (a);//create a map object replication transfer 
Map3. Put (" title ", the title); 
Map3. Put (" for its pubDate, "for its pubDate); 
Map3. Put (" author ", the author); 
Map3. Put (" description ", the description); 

Itmes. Add (map3);//put the map object in the list collection inside 


The LVS. SetAdapter (new SimpleAdapter (MainActivity. This itmes, R.l ayout. Lv2, new String [] {" title ", "for its pubDate", "the author"} 
, new int [] {R.i which xt_count, R.i which xt_Date, R.i which xt_author})); 
The LVS. SetOnItemClickListener ((the parent, the view, position, id) - & gt; {
News News=newsList. Get (position); 
Bundle bundle=new Bundle(); 
Bundle. PutString (" title ", news getTitle ()); 
Bundle. PutString (" time ", for its pubDate); 
Bundle. PutString (" author ", the author); 
Bundle. PutString (" description ", the description); 

Intent Intent=new Intent (MainActivity. This, NewsDescription. Class); 
Intent. PutExtras (bundle); 
startActivity(intent); 
}); 
} 
}; 




//create a method of the download file 
Public void the download () {

//create a worker Thread, inherit the Thread to run method, processing time consuming operation 
New Thread () {//create the child Thread quotation download process is a slow process, the main Thread can not use a 

//rewrite the run () method, 
@ Override 
Public void the run () {
Try {
The Context Context=MainActivity. This. GetApplication ();//get a Context object 
String path=context. GetFilesDir () + "/test. The XML";//purpose in order to obtain the android file directory 
String url1=url;//create a download link 
URL the URL=new URL (url1);//create a URL 
HttpURLConnection con=(HttpURLConnection) url. OpenConnection ();//get an HttpURLConnection object con 
Con. SetConnectTimeout (3 * 1000); 
//to prevent blocking fetching and returns a 403 error 
Con. SetRequestProperty (" the user-agent ", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT. DigExt) "); 

InputStream iso=con. GetInputStream ();//get an input stream iso object by con 
File file=new File(path);//create a file object to write path into the 
FileOutputStream fos=new FileOutputStream (file); 
Byte [] b=new byte [1024]. 
int count=0; 
While ((count=iso. Read (b, 0102 (4)).=1) {
Fos. Write (b, 0, count); 
System. The out. Print (b + "/KB"); 
} 
fos.close(); 
Iso. The close (); 

List Pull pull=();//call the Pull parse () method to parse the XML document and returns List Object 

For (News n: pull) {//traverse the list collection 
The Message MSG=new Message ();//create a Message object M 
MSG. Obj=n;//the message object can accept any type of object and can be through a reverse casts back 
Handler. SendMessage (MSG); 
} 

} 
The catch (Exception e) {
System. The out. Println (um participant etMessage ()); 
} 
} 
}.start(); 
} 

Public List Pull () {
Try {

The Context Context=MainActivity. This. GetApplication (); 
The String url=context. GetFilesDir () + "/test. The XML"; 
InputStream fis=new FileInputStream (url); 

List List=NewsPull. The getNews (fis); 
For (News n: list) {
System.out.println(n); 
} 
return list; 
} the catch (Exception e) {
e.printStackTrace(); 
Return null; 
{} the catch (Throwable Throwable) 
Throwable. PrintStackTrace (); 
Return null; 
} 

} 

} 

Which how to obtain the LVS Settings click event to the corresponding title, date, author and description to the next interface
?As the current News News=newsList. Get (position); Don't know why complains about this for a Java lang. IndexOutOfBoundsException: Index: 3, Size: 0
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