eclipse - Problems with XmlPullParser code inside an AsyncTask (Activated By Button Click) -

so have program have been working on while. however, stuck on method uses xmlpullparser, method called getallxml(). inside of doinbackground() method of asynctask. asynctask subclass of activity called formactivity. when run code.

here code supposed do. after user selects "cloverfield" previous activity. xml file called cloverfield_in.xml called setcontentview(). user presses button on same xml file. clicking button executes asynctask called madlibasynctask. within asynctask 2 methods, doinbackground() , onpostexecute(). (i don't know if need onpreexecute()...within have have progress bar....but without method figure program shouldn't crash way does).

within doinbackground() method, calling method called getallxml(). method uses xmlpullparser search through current xml (cloverfield_in.xml) , capture text single textview. code getallxml() follows.

public void getallxml() throws xmlpullparserexception, ioexception{     activity activity = this;      resources res  = activity.getresources();     xmlresourceparser xpp = res.getxml(r.layout.cloverfield_in);         int eventtype = xpp.geteventtype();         while (eventtype != xmlpullparser.end_document){             if (eventtype == xmlpullparser.start_document){               }             else if (eventtype == xmlpullparser.start_tag){                 if (xpp.getname() == "textview"){                     while (eventtype != xmlpullparser.end_tag){                         if (eventtype == xmlpullparser.text){                         stringviews[0] =  xpp.gettext();                          }else {}                         eventtype = xpp.next();                      }                 }else {}             }             else if (eventtype == xmlpullparser.end_tag){              }             else if (eventtype == xmlpullparser.text){             }             eventtype = xpp.next();         } } 

when in process of debugging, program returns nullpointerexception or runtimeexception. believe within code problem resides. tested asynctask without existence of getallxml() method , works fine. program supposed take text gathered cloverfield_in.xml file , display in new file called cloverfield_out.xml.

for complete review of everything, here entire code formactivity.class.

package com.muirconsult.mymadlibs;  import java.io.file; import java.io.fileinputstream; import java.io.filereader; import java.io.ioexception;  import org.xmlpull.v1.xmlpullparser; import org.xmlpull.v1.xmlpullparserexception; import org.xmlpull.v1.xmlpullparserfactory;  import android.app.activity; import android.content.context; import android.content.intent; import android.content.res.resources; import android.content.res.xmlresourceparser; import android.os.asynctask; import android.os.bundle; import android.os.handler; import android.os.message; import android.text.layout; import android.util.log; import android.view.view; import android.view.viewgroup; import android.widget.autocompletetextview; import android.widget.textview;  public class formactivity extends activity{          string [] textfields;     string choice;     int thislayout;     view thatlayout ;     string[] stringviews;     viewgroup anskey;     activity activity = this;     string test;      protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);          intent objintent = getintent();         choice = objintent.getstringextra("selection");          if (choice.equals("cloverfield")) {             setcontentview(r.layout.cloverfield_in);             thislayout = (r.layout.cloverfield_in);             thatlayout = (view)findviewbyid(r.layout.cloverfield_out);          }         if (choice.equals("fargo"))  {             setcontentview(r.layout.fargo_in);         }         if(choice.equals("ying yang in thang (ying yang twins)")){             setcontentview(r.layout.ying_yang_twins_in_this_thang_in);                 }       }  public void getallxml() throws xmlpullparserexception, ioexception{     activity activity = this;      resources res  = activity.getresources();     xmlresourceparser xpp = res.getxml(r.layout.cloverfield_in);         int eventtype = xpp.geteventtype();         while (eventtype != xmlpullparser.end_document){             if (eventtype == xmlpullparser.start_document){               }             else if (eventtype == xmlpullparser.start_tag){                 if (xpp.getname() == "textview"){                     while (eventtype != xmlpullparser.end_tag){                         if (eventtype == xmlpullparser.text){                                stringviews[0] =  xpp.gettext();                          }else {}                         eventtype = xpp.next();                      }                 }else {}             }             else if (eventtype == xmlpullparser.end_tag){              }             else if (eventtype == xmlpullparser.text){             }             eventtype = xpp.next();         } }       class madlibasynctask extends asynctask<void, void, void>{     string teststring;     int thislayout;      protected void doinbackground(void... params) {      try{         getallxml();     }catch (xmlpullparserexception e){         e.printstacktrace();     }catch (ioexception e){         e.printstacktrace();     }          return null;     }      protected void onpostexecute (void result){         string str = "let's go park";         string newstr;          setcontentview(r.layout.cloverfield_out);         textview outview = (textview)findviewbyid(r.id.outview);         str = (string) outview.gettext();         newstr = str.replacefirst("film",stringviews[0]);         outview.settext(newstr);      }  }              public void onclick(view view) {                 madlibasynctask mad = new madlibasynctask();         mad.execute();        }  } 

also, importantly...the logcat looks such:

08-10 23:04:50.064: w/dalvikvm(1415): threadid=1: thread exiting uncaught exception >>>  (group=0x40a71930)  08-10 23:04:50.145: e/androidruntime(1415): fatal exception: main  08-10 23:04:50.145: e/androidruntime(1415): java.lang.nullpointerexception  08-10 23:04:50.145: e/androidruntime(1415):     @ java.util.regex.matcher.appendevaluated>(matcher.java:130)  08-10 23:04:50.145: e/androidruntime(1415):     @ java.util.regex.matcher.appendreplacement(matcher.java:110)  08-10 23:04:50.145: e/androidruntime(1415):     @ java.util.regex.matcher.replacefirst(matcher.java:299)  08-10 23:04:50.145: e/androidruntime(1415):     @ java.lang.string.replacefirst(string.java:1793) 08-10 23:04:50.145: e/androidruntime(1415):     @ com.muirconsult.mymadlibs.formactivity$madlibasynctask.onpostexecute(formactivity.java:116)  08-10 23:04:50.145: e/androidruntime(1415):     @     com.muirconsult.mymadlibs.formactivity$madlibasynctask.onpostexecute(formactivity.java:1)  08-10 23:04:50.145: e/androidruntime(1415):     @ android.os.asynctask.finish(asynctask.java:631)  08-10 23:04:50.145: e/androidruntime(1415):     @ android.os.asynctask.access$600>\ (asynctask.java:177)  08-10 23:04:50.145: e/androidruntime(1415):     @     android.os.asynctask$internalhandler.handlemessage(asynctask.java:644)  08-10 23:04:50.145: e/androidruntime(1415):     @ android.os.handler.dispatchmessage(handler.java:99)  08-10 23:04:50.145: e/androidruntime(1415):     @ android.os.looper.loop(looper.java:137)  08-10 23:04:50.145: e/androidruntime(1415):     @ android.app.activitythread.main(activitythread.java:5041)  08-10 23:04:50.145: e/androidruntime(1415):     @ java.lang.reflect.method.invokenative(native method)  08-10 23:04:50.145: e/androidruntime(1415):     @ java.lang.reflect.method.invoke(method.java:511)  08-10 23:04:50.145: e/androidruntime(1415):     @     com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:793)  08-10 23:04:50.145: e/androidruntime(1415):     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:560)  08-10 23:04:50.145: e/androidruntime(1415):     @ dalvik.system.nativestart.main(native method)