Error Parsing xml file from sd card in Android -

i have written code parsing , showing data xml file. not working. showing error @ main activity. androidxmlparsingactivity:

package com.androidhive.xmlparsing;  import java.util.arraylist; import java.util.hashmap;  import org.w3c.dom.document; import org.w3c.dom.element; import org.w3c.dom.nodelist;  import android.app.listactivity; import android.content.intent; import android.os.bundle; import android.view.view; import android.widget.adapterview; import android.widget.adapterview.onitemclicklistener; import android.widget.listadapter; import android.widget.listview; import android.widget.simpleadapter; import android.widget.textview;  public class androidxmlparsingactivity extends listactivity {      // static variables     static final string url = "file:///sdcard/download.xml";     // xml node keys     static final string key_item = "item"; // parent node     static final string key_id = "id";     static final string key_name = "name";     static final string key_cost = "cost";     static final string key_desc = "description";      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.main);          arraylist<hashmap<string, string>> menuitems = new arraylist<hashmap<string, string>>();          xmlparser parser = new xmlparser();         string xml = parser.getxmlfromurl(url); // getting xml         document doc = parser.getdomelement(xml); // getting dom element          nodelist nl = doc.getelementsbytagname(key_item);         // looping through item nodes <item>         (int = 0; < nl.getlength(); i++) {             // creating new hashmap             hashmap<string, string> map = new hashmap<string, string>();             element e = (element) nl.item(i);             // adding each child node hashmap key => value             map.put(key_id, parser.getvalue(e, key_id));             map.put(key_name, parser.getvalue(e, key_name));             map.put(key_cost, "rs." + parser.getvalue(e, key_cost));             map.put(key_desc, parser.getvalue(e, key_desc));              // adding hashlist arraylist             menuitems.add(map);         }          // adding menuitems listview         listadapter adapter = new simpleadapter(this, menuitems,                 r.layout.list_item,                 new string[] { key_name, key_desc, key_cost }, new int[] {                         r.id.name, r.id.desciption, r.id.cost });          setlistadapter(adapter);          // selecting single listview item         listview lv = getlistview();          lv.setonitemclicklistener(new onitemclicklistener() {              @override             public void onitemclick(adapterview<?> parent, view view,                     int position, long id) {                 // getting values selected listitem                 string name = ((textview) view.findviewbyid(r.id.name)).gettext().tostring();                 string cost = ((textview) view.findviewbyid(r.id.cost)).gettext().tostring();                 string description = ((textview) view.findviewbyid(r.id.desciption)).gettext().tostring();                  // starting new intent                 intent in = new intent(getapplicationcontext(), singlemenuitemactivity.class);                 in.putextra(key_name, name);                 in.putextra(key_cost, cost);                 in.putextra(key_desc, description);                 startactivity(in);              }         });     } } 

and log cat here:

10-06 19:06:34.849: w/dalvikvm(25780): threadid=1: thread exiting uncaught exception (group=0x40d452a0) 10-06 19:06:34.849: e/androidruntime(25780): fatal exception: main 10-06 19:06:34.849: e/androidruntime(25780): java.lang.runtimeexception: unable start activity componentinfo{com.androidhive.xmlparsing/com.androidhive.xmlparsing.androidxmlparsingactivity}: java.lang.illegalargumentexception: host name may not null 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.activitythread.performlaunchactivity(activitythread.java:2100) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.activitythread.handlelaunchactivity(activitythread.java:2125) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.activitythread.access$600(activitythread.java:140) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.activitythread$h.handlemessage(activitythread.java:1227) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.os.handler.dispatchmessage(handler.java:99) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.os.looper.loop(looper.java:137) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.activitythread.main(activitythread.java:4898) 10-06 19:06:34.849: e/androidruntime(25780):    @ java.lang.reflect.method.invokenative(native method) 10-06 19:06:34.849: e/androidruntime(25780):    @ java.lang.reflect.method.invoke(method.java:511) 10-06 19:06:34.849: e/androidruntime(25780):    @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:1006) 10-06 19:06:34.849: e/androidruntime(25780):    @ com.android.internal.os.zygoteinit.main(zygoteinit.java:773) 10-06 19:06:34.849: e/androidruntime(25780):    @ de.robv.android.xposed.xposedbridge.main(xposedbridge.java:112) 10-06 19:06:34.849: e/androidruntime(25780):    @ dalvik.system.nativestart.main(native method) 10-06 19:06:34.849: e/androidruntime(25780): caused by: java.lang.illegalargumentexception: host name may not null 10-06 19:06:34.849: e/androidruntime(25780):    @ org.apache.http.httphost.<init>(httphost.java:83) 10-06 19:06:34.849: e/androidruntime(25780):    @ org.apache.http.impl.client.abstracthttpclient.determinetarget(abstracthttpclient.java:519) 10-06 19:06:34.849: e/androidruntime(25780):    @ org.apache.http.impl.client.abstracthttpclient.execute(abstracthttpclient.java:509) 10-06 19:06:34.849: e/androidruntime(25780):    @ org.apache.http.impl.client.abstracthttpclient.execute(abstracthttpclient.java:487) 10-06 19:06:34.849: e/androidruntime(25780):    @ com.androidhive.xmlparsing.xmlparser.getxmlfromurl(xmlparser.java:45) 10-06 19:06:34.849: e/androidruntime(25780):    @ com.androidhive.xmlparsing.androidxmlparsingactivity.oncreate(androidxmlparsingactivity.java:40) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.activity.performcreate(activity.java:5206) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1083) 10-06 19:06:34.849: e/androidruntime(25780):    @ android.app.activitythread.performlaunchactivity(activitythread.java:2064) 10-06 19:06:34.849: e/androidruntime(25780):    ... 12 more 10-06 19:06:34.854: d/windowmanager(2297): minputfocus not null. 10-06 19:06:34.904: e/android.os.debug(2297): !@dumpstate > dumpstate -k -t -z -d -o /data/log/dumpstate_app_error 

i have kept download.xml file in sd card. no problem location know. can not find out problem. please me solve this.

here xmlparser class:

package com.androidhive.xmlparsing;  import java.io.ioexception; import java.io.stringreader; import java.io.unsupportedencodingexception;  import javax.xml.parsers.documentbuilder; import javax.xml.parsers.documentbuilderfactory; import javax.xml.parsers.parserconfigurationexception;  import org.apache.http.httpentity; import org.apache.http.httpresponse; import org.apache.http.client.clientprotocolexception; import org.apache.http.client.methods.httppost; import org.apache.http.impl.client.defaulthttpclient; import org.apache.http.util.entityutils; import org.w3c.dom.document; import org.w3c.dom.element; import org.w3c.dom.node; import org.w3c.dom.nodelist; import org.xml.sax.inputsource; import org.xml.sax.saxexception;  import android.util.log;  public class xmlparser {      // constructor     public xmlparser() {      }      /**      * getting xml url making http request      * @param url string      * */     public string getxmlfromurl(string url) {         string xml = null;          try {             // defaulthttpclient             defaulthttpclient httpclient = new defaulthttpclient();             httppost httppost = new httppost(url);              httpresponse httpresponse = httpclient.execute(httppost);             httpentity httpentity = httpresponse.getentity();             xml = entityutils.tostring(httpentity);          } catch (unsupportedencodingexception e) {             e.printstacktrace();         } catch (clientprotocolexception e) {             e.printstacktrace();         } catch (ioexception e) {             e.printstacktrace();         }         // return xml         return xml;     }      /**      * getting xml dom element      * @param xml string      * */     public document getdomelement(string xml){         document doc = null;         documentbuilderfactory dbf = documentbuilderfactory.newinstance();         try {              documentbuilder db = dbf.newdocumentbuilder();              inputsource = new inputsource();                 is.setcharacterstream(new stringreader(xml));                 doc = db.parse(is);               } catch (parserconfigurationexception e) {                 log.e("error: ", e.getmessage());                 return null;             } catch (saxexception e) {                 log.e("error: ", e.getmessage());                 return null;             } catch (ioexception e) {                 log.e("error: ", e.getmessage());                 return null;             }              return doc;     }      /** getting node value       * @param elem element       */      public final string getelementvalue( node elem ) {          node child;          if( elem != null){              if (elem.haschildnodes()){                  for( child = elem.getfirstchild(); child != null; child = child.getnextsibling() ){                      if( child.getnodetype() == node.text_node  ){                          return child.getnodevalue();                      }                  }              }          }          return "";      }       /**       * getting node value       * @param element node       * @param key string       * */      public string getvalue(element item, string str) {                  nodelist n = item.getelementsbytagname(str);                     return this.getelementvalue(n.item(0));         } }