JAVA словил ошибку unreachable statement не могу разобраться

делал калькулятор по заданному образцу и поймал ошибку в строке: 'calcDialogDisplay.setText("");' Сам код:

package com.example.buuuuum;
import android.content.pm.ActivityInfo;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity 
implements View.OnClickListener {
private Button plus;
private Button minus;
private Button umnogenie;
private Button delenie;
private Button tochka;
private Button cteret;
private TextView text1;
private EditText vvod1;
private EditText vvod2;
private  float a,b;
EditText calcDialogDisplay;
final static int CLEAR = 1;
final static int DONT_CLEAR = 0;
int clearCalcDisplay = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    tochka=(Button) findViewById(R.id.button2);
    cteret=(Button) findViewById(R.id.button);
    plus = (Button) findViewById(R.id.button9);
    minus= (Button) findViewById(R.id.button10);
    delenie= (Button) findViewById(R.id.button11);
    umnogenie= (Button) findViewById(R.id.button12);
    text1= (TextView) findViewById(R.id.textView);
    vvod1= (EditText) findViewById(R.id.editText);
    vvod2= (EditText) findViewById(R.id.editText2);
    calcDialogDisplay = (EditText) findViewById(R.id.editText);
    plus.setOnClickListener(this);
    minus.setOnClickListener(this);
    delenie.setOnClickListener(this);
    umnogenie.setOnClickListener(this);
    vvod1.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            if(s == null){
                a= 0;
            }
            else {
                a = Integer.parseInt(s.toString());
            }
        }
        @Override
        public void afterTextChanged(Editable s) {
        }
    });
    vvod2.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            if(s == null){
                b= 0;
            }
            else {
                b = Integer.parseInt(s.toString());
            }
        }
        @Override
        public void afterTextChanged(Editable s) {
        }
    });
}
@Override
public void onClick(View v) {
    switch (v.getId()){
        case R.id.button9: text1.setText(String.valueOf(a+b));
            break;
        case R.id.button10: text1.setText(String.valueOf(a-b));
            break;
        case R.id.button11: text1.setText(String.valueOf(a/b));
            break;
        case R.id.button12: text1.setText(String.valueOf(a*b));
            break;
        if (clearCalcDisplay == CLEAR) {
       calcDialogDisplay.setText("");
        } else
        clearCalcDisplay = DONT_CLEAR;
        calcDialogDisplay.append("7");

    }
}
}