Android Studio Java - Which modifier should I use? -

i'm kind of new android studio , java bear me please.

i'm making app can keep scores dart game. have switch statement button clicked. when enter button pressed, want go java file while using 1 argument, input. apparently use both static , non static methods , wrong. how fix this?

here first java file, witch screen file:

package com.example.jeroe.darts;  import android.os.bundle; import android.support.v7.app.appcompatactivity;  import android.view.view; import android.widget.textview; import com.example.jeroe.darts.score;   public class matchscreen extends appcompatactivity implements view.onclicklistener{  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.content_match_screen);      defineeventhandlers(); }  public void onclick(view v) {     textview inputtrue = (textview) findviewbyid(r.id.textviewinput);     textview edittextscore = (textview) findviewbyid(r.id.edittextscore);     switch (v.getid()) {         case r.id.textviewinnerbull:             edittextscore.append("50");             break;         case r.id.textviewouterbull:             edittextscore.append("25");             break;         case r.id.textviewclear:             edittextscore.settext("");             break;         case r.id.textviewenter:              score.enter(edittextscore.gettext());             // here error:             //non-static method 'enter(charsequence)' cannot referenced static context      } }  public void defineeventhandlers() {     // declare textviews player 1     textview textviewpl1score = (textview) findviewbyid(r.id.textviewpl1score);     textview pl1dart1 = (textview) findviewbyid(r.id.pl1dart1);     textview pl1dart2 = (textview) findviewbyid(r.id.pl1dart2);     textview pl1dart3 = (textview) findviewbyid(r.id.pl1dart3);      // declare textviews player 2     textview textviewpl2score = (textview) findviewbyid(r.id.textviewpl2score);     textview pl2dart1 = (textview) findviewbyid(r.id.pl2dart1);     textview pl2dart2 = (textview) findviewbyid(r.id.pl2dart2);     textview pl2dart3 = (textview) findviewbyid(r.id.pl2dart3);      //t20, bulls     textview textviewouterbull = (textview) findviewbyid(r.id.textviewouterbull);     textviewouterbull.setonclicklistener(this);     textview textviewinnerbull = (textview) findviewbyid(r.id.textviewinnerbull);     textviewinnerbull.setonclicklistener(this);      //enter, backspace     textview textviewclear = (textview) findviewbyid(r.id.textviewclear);     textviewclear.setonclicklistener(this);     textview textviewenter = (textview) findviewbyid(r.id.textviewenter);     textviewenter.setonclicklistener(this); }  } //end of file 

then need go file called score.java. here want keep score , other things:

package com.example.jeroe.darts;  public class score { int pl1score = 501; boolean player1 = true;  public void enter(charsequence input) {      int intinput = inputconverter(input);      if (player1 == true) //de input = player 1     {         //     } }    public int inputconverter(charsequence input) {     int input = integer.parseint(input.tostring());     return input; }  } 

how fix this?

//non-static method 'enter(charsequence)' cannot referenced static context 

it means need instance of score:

score score = new score(); score.enter(edittextscore.gettext());