Clear runtime memory

package com.sanedu.memorytesting;

import androidx.appcompat.app.AppCompatActivity;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivityTag";
    Button clearMemory, increaseMemory;

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

        clearMemory = findViewById(R.id.clear_memory);
        increaseMemory = findViewById(R.id.inc_memory);


        // Clear memory button
        clearMemory.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                System.runFinalization();
                Runtime.getRuntime().gc();
                System.gc();
                printRuntimeMemory();
            }
        });
        // Button used to increase memory
        increaseMemory.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                incMemory();
                printRuntimeMemory();
            }
        });
    }

// Function used to print runtime memory
    private void printRuntimeMemory(){
        Runtime runtime = Runtime.getRuntime();
        long runtimeMax = -1;
        long runtimeTotal = -1;
        long runtimeFree = -1;
        long runtimeUsed = -1;

        if (runtime != null) {
            runtimeMax = runtime.maxMemory();
            runtimeTotal = runtime.totalMemory();
            runtimeFree = runtime.freeMemory();
            runtimeUsed = runtimeTotal - runtimeFree;
        }
        Log.d(TAG, "printRuntimeMemory: Free: " + runtimeFree +" Used: " + runtimeUsed);
    }

// Function used to increase memory usage
    private void incMemory(){
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_AIRPLANE_MODE_CHANGED);

        BroadcastReceiver receiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                //do something based on the intent's action
            }
        };
        registerReceiver(receiver, filter);
    }
}