java - How can I create RequiredFieldValidattion in Android? -

here code. looks bit complicated it's working fine. want know how can create when click btncreateproduct should validate required edit text field , add code?

package com.prinsapps.whatson;   import java.util.calendar; import android.app.activity; import android.app.datepickerdialog; import android.app.dialog; import android.os.bundle; import android.view.view; import android.app.progressdialog; import android.content.intent; import android.os.asynctask; import android.util.log; import android.widget.button; import android.view.view.onclicklistener; import android.widget.datepicker; import android.widget.edittext; import android.widget.imagebutton; import java.util.arraylist; import java.util.list; import org.apache.http.namevaluepair; import org.apache.http.message.basicnamevaluepair; import org.json.jsonexception; import org.json.jsonobject; import com.prinsapps.whatson.addevent.createnewproduct;    public class addevent extends activity implements onclicklistener {   private imagebutton ib;   private calendar cal;   private int day;   private int month;   private int year;   private edittext et;  //progress dialog   private progressdialog pdialog;  jsonparser jsonparser = new jsonparser();   edittext inputname;   edittext inputdesc;   edittext inputcountry;   edittext inputdate;   edittext inputlink;   edittext inputorg; // url create new product   private static string url_create_product = "http://-----------";  // json node names   private static final string tag_success = "success";  @override   protected void oncreate(bundle savedinstancestate) {   super.oncreate(savedinstancestate);   setcontentview(r.layout.add_event);  //edit text   inputname = (edittext) findviewbyid(r.id.inputname);   inputdesc = (edittext) findviewbyid(r.id.inputdesc);   inputcountry = (edittext) findviewbyid(r.id.inputcountry);   inputdate = (edittext) findviewbyid(r.id.inputdate);   inputlink = (edittext) findviewbyid(r.id.inputlink);   inputorg = (edittext) findviewbyid(r.id.inputorg);  // mdatebutton = (button) findviewbyid(r.id.date_button);   ib = (imagebutton) findviewbyid(r.id.imagebutton1);   cal = calendar.getinstance();   day = cal.get(calendar.day_of_month);   month = cal.get(calendar.month);   year = cal.get(calendar.year);   et = (edittext) findviewbyid(r.id.inputdate);       ib.setonclicklistener(this);  // create button   button btncreateproduct = (button)     findviewbyid(r.id.btncreateproduct);  // button click event   btncreateproduct.setonclicklistener(new view.onclicklistener() {      @override     public void onclick(view view) {         // creating new product in background thread         new createnewproduct().execute();     } }); }   @override   public void onclick(view v) {   showdialog(0);   }  @override @deprecated   protected dialog oncreatedialog(int id) {   return new datepickerdialog(this, datepickerlistener, year, month, day); }    private datepickerdialog.ondatesetlistener datepickerlistener = new   datepickerdialog.ondatesetlistener() {   public void ondateset(datepicker view, int selectedyear,   int selectedmonth, int selectedday) {   et.settext(selectedyear+"/"+(selectedmonth+1)+"/"+selectedday); } };  /**  * background async task create new product  * */   class createnewproduct extends asynctask<string, string, string> {      /**      * before starting background thread show progress dialog      * */     @override       protected void onpreexecute() {           super.onpreexecute();           pdialog = new progressdialog(addevent.this);           pdialog.setmessage("creating product..");           pdialog.setindeterminate(false);           pdialog.setcancelable(true);           pdialog.show();     }      /**      * creating product      *       * */       protected string doinbackground(string... args) {           string name = inputname.gettext().tostring();           string description = inputdesc.gettext().tostring();           string country = inputcountry.gettext().tostring();           string date = inputdate.gettext().tostring();           string link = inputlink.gettext().tostring();           string org = inputorg.gettext().tostring();          // building parameters           list<namevaluepair> params = new arraylist<namevaluepair>();           params.add(new basicnamevaluepair("name", name));           params.add(new basicnamevaluepair("description", description));           params.add(new basicnamevaluepair("country", country));           params.add(new basicnamevaluepair("date", date));           params.add(new basicnamevaluepair("link", link));           params.add(new basicnamevaluepair("org", org));          // getting json object         // note create product url accepts post method         jsonobject json = jsonparser.makehttprequest(url_create_product,                 "post", params);          // check log cat fro response         log.d("create response", json.tostring());          // check success tag         try {             int success = json.getint(tag_success);              if (success == 1) {                 // created product                 intent = new intent(getapplicationcontext(),                 allproductsactivity.class);                 startactivity(i);                  // closing screen                 finish();             } else {                 // failed create product             }         } catch (jsonexception e) {             e.printstacktrace();         }          return null;     }      /**      * after completing background task dismiss progress dialog      * **/     protected void onpostexecute(string file_url) {         // dismiss dialog once done         pdialog.dismiss();     }  }   } 

as i'm assuming, don't want empty textfield empty if creating product, i'd suggest check wether strings of edittexts null or empty.

this this:

if(inputname.gettext().equals("") || inputname.gettext().equals(null)){ //maybe show message, given field ist required filled out } 

i suggest add onclick() method, or write method check wether edittext empty , return boolean value. this:

public boolean notempty(edittext et){ if(et.gettext().equals("") || et.gettext().equals(null)){ return false; } return true; } 

and check every edittext et before create new product.