java - android web browser does not open url -

i want open url through browser when click on button not open url please tell me made mistake. here code of java file.

 public class mainactivity extends appcompatactivity {      button button;     edittext edittext;     webview webview;     @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);         button = (button)findviewbyid(r.id.but);         edittext = (edittext)findviewbyid(r.id.edittext);         webview = (webview)findviewbyid(r.id.webview);        }       public void goo(view view){         string url = edittext.gettext().tostring();         webview.getsettings().setloadsimagesautomatically(true);         webview.getsettings().setjavascriptenabled(true);         webview.loadurl(url);     } } 

here xml file

    <?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical"     >       <textview         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="enter url"         android:id="@+id/textview"         />     <edittext         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:id="@+id/edittext"/>      <button         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:onclick="goo"         android:text="go"         android:id="@+id/but"         />      <webview         android:layout_width="fill_parent"         android:layout_height="match_parent"         android:id="@+id/webview" />   </linearlayout> 

when click on button not open page , in logcat show message

in activity copy paste following code...

public class mainactivity extends appcompatactivity {      button button1, button2;     edittext edittext;     webview webview;     string url;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);         button1 = (button)findviewbyid(r.id.but);         button2 = (button)findviewbyid(r.id.but1);         edittext = (edittext)findviewbyid(r.id.edittext);         webview = (webview)findviewbyid(r.id.webview);         button1.setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view view) {                 url=edittext.gettext().tostring();                 url="http://"+url;                 loadurl(url);             }         });        button2.setonclicklistener(new view.onclicklistener() {            @override            public void onclick(view view) {                url="http://www.stackoverflow.com";                loadurl(url);            }        });      }      public void loadurl(string url) {         webview.getsettings().setjavascriptenabled(true);         webview.getsettings().setbuiltinzoomcontrols(true);         webview.getsettings().setusewideviewport(true);         webview.getsettings().setloadwithoverviewmode(true);         webview.getsettings().setdomstorageenabled(true);         webview.setvisibility(view.visible);             webview.loadurl(url);             webview.setwebviewclient(new webviewclient() {                 @override                 public boolean shouldoverrideurlloading(webview view, string url) {                     view.loadurl(url);                     return true;                 }             });         } } 

and in manifest file.. add these 2 lines..

<uses-permission android:name="android.permission.access_network_state" />     <uses-permission android:name="android.permission.internet" /> 

in xml, added,

 <button             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="go"             android:id="@+id/but"             />     <button         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="fb"         android:id="@+id/but1"         />