android - Search and pull the results by entering the initials of the word -

how can filter result if user enters initials. example if in list item "george washington" if user enters "g w" in searchbox shows result. below class

public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      // listview data     string products[] = {"dell inspiron", "htc 1 x", "htc wildfire s", "htc sense", "htc sensation xe",                             "iphone 4s", "samsung galaxy note 800",                             "samsung galaxy s3", "macbook air", "mac mini", "macbook pro"};      lv = (listview) findviewbyid(r.id.list_view);     inputsearch = (edittext) findviewbyid(r.id.inputsearch);      // adding items listview     adapter = new arrayadapter<string>(this, r.layout.list_item, r.id.product_name, products);     lv.setadapter(adapter);      /**      * enabling search filter      * */     inputsearch.addtextchangedlistener(new textwatcher() {          @override         public void ontextchanged(charsequence cs, int arg1, int arg2, int arg3) {             // when user changed text             mainactivity.this.adapter.getfilter().filter(cs);            }          @override         public void beforetextchanged(charsequence arg0, int arg1, int arg2,                 int arg3) {             // todo auto-generated method stub          }          @override         public void aftertextchanged(editable arg0) {             // todo auto-generated method stub                                   }     });    }        } 

you need set content provider , query provider results each time user enters letter.