Error while using the Integer.parseInt() function in Android Studio [duplicate]

 public void clickFunction(View view)
    {
        Log.i("Info","Button Pressed");
        EditText e1=(EditText)findViewById(editText);
        Number myNumber= new Number();
        String NumberEnteredStr = e1.getText().toString();
        Log.i("Number Entered",NumberEnteredStr);
        myNumber.num = Integer.parseInt(NumberEnteredStr);//line 22
    }

I entered the entire code correctly bit by bit until the app crashed while I entered the code on line no. 22. There seems to be some problem with the conversion to int. Please help me out.

PS- I have tried removing different parts of the code to debug and the problem lies somewhere in the remaining portion, possibly in the clickFunction (onClick) method.

My error messages are :

    Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invoke(Native Method)
    at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
    at android.view.View.performClick(View.java:6294) 
    at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119) 
    at android.view.View$PerformClick.run(View.java:24770) 
    at android.os.Handler.handleCallback(Handler.java:790) 
    at android.os.Handler.dispatchMessage(Handler.java:99) 
    at android.os.Looper.loop(Looper.java:164) 
    at android.app.ActivityThread.main(ActivityThread.java:6494) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 
 Caused by: java.lang.NumberFormatException: For input string: ""
    at java.lang.Integer.parseInt(Integer.java:620)
    at java.lang.Integer.parseInt(Integer.java:643)
    at com.example.numbershapes.MainActivity.clickFunction(MainActivity.java:22)

I am putting down my entire code for reference :

package com.example.numbershapes;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import androidx.appcompat.app.AppCompatActivity;
import static com.example.numbershapes.R.id.editText;

public class MainActivity extends AppCompatActivity
{
    class Number
    {
        int num;
    }
    public void clickFunction(View view)
    {
        Log.i("Info","Button Pressed");
        EditText e1=(EditText)findViewById(editText);
        Number myNumber= new Number();
        String NumberEnteredStr = e1.getText().toString();
        Log.i("Number Entered",NumberEnteredStr);
        myNumber.num = Integer.parseInt(NumberEnteredStr);//line 22
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}