My application crashes when I click a button (android studio)

Question

Whenever I try the apk in my mobile, it crashes. I am sure it is not because of less ram or cache memory. I tries many things but they do not work. Firstly when I was adding functions to the buttons in the designing tab, then also it crashed. I searched othe forms but they did not also helped. Pls help. I have seen other forms but they dont help me at all.

    package com.example.project1calculator;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    public EditText s1;
    public EditText s2;
    public Button sum;
    public Button dif;
    public Button mul;
    public Button div;
    public int total;
    public TextView result;
    public Button clear;
    public String text1;
    public int int1;
    public String text2;
    public int int2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        s1 = findViewById(R.id.editTextTextPersonName2);
        s2 = findViewById(R.id.editTextTextPersonName3);
        sum = findViewById(R.id.button2);
        dif = findViewById(R.id.button);
        mul = findViewById(R.id.button3);
        div = findViewById(R.id.button4);
        result = findViewById(R.id.result);
        clear = findViewById(R.id.clear);

        sum.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                text1 = s1.getText().toString();
                int1 = Integer.parseInt(text1);

                text2 = s2.getText().toString();
                int2 = Integer.parseInt(text2);

                total = int1 + int2;
                result.setText(total);

            }
        });

        dif.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                text1 = s1.getText().toString();
                int1 = Integer.parseInt(text1);

                text2 = s2.getText().toString();
                int2 = Integer.parseInt(text2);

                total = int1 - int2;
                result.setText(total);
            }
        });

        mul.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                text1 = s1.getText().toString();
                int1 = Integer.parseInt(text1);

                text2 = s2.getText().toString();
                int2 = Integer.parseInt(text2);

                total = int1 * int2;
                result.setText(total);
            }
        });

        div.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                text1 = s1.getText().toString();
                int1 = Integer.parseInt(text1);

                text2 = s2.getText().toString();
                int2 = Integer.parseInt(text2);

                total = int1 / int2;
                result.setText(total);
            }
        });

        clear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                text1 = "";
                text2 = "";
                int1 = 0;
                int2 = 0;
            }
        });
    }


}