Android Studio reduce memory usage of PC

public class Main extends Activity {

private TextView mTextView;
private Activity mAct;
private Intent mIntent;

protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main_layout);
  mTextView = findViewById(R.id.mTextView);
  mAct = getActivity();
  mIntent = getIntent();
 }

}

public class Main extends Fragment{

 private TextView mTextView;
 private FragmentActivity mFrgAct;
 private Intent mIntent;
 private LinearLayout mLinearLayout;
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
          Bundle savedInstanceState) {
          View root = inflater.inflate(R.layout.fragment_main, null);
        return root;
    }

 public void onViewCreated(View view, Bundle savedInstanceState) {
          // you can add listener of elements here
          /*Button mButton = (Button) view.findViewById(R.id.button);
            mButton.setOnClickListener(this); */
          mTextView = view.findViewById(R.id.mTextView);
          mLinearLayout = (LinearLayout)view;
 }
 public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
          mFrgAct = getActivity();
          mIntent = mFrgAct.getIntent(); //  Intent intent = new Intent(getActivity().getIntent());
 }

}

public class MainClass {
	public static void main(String[] arg) {
		String[] arrayOfString = { "Hello", "people", "hello", "world!" };
                int i = 0;
		while ( i < arrayOfString.length ){
			System.out.println(arrayOfString[i]);
			i++;
		}
	}
}

	public void callFc() 
	throws IndexOutOfBoundsException, ArithmeticException
	{
         // my code for example:
         String[] sArray = {"aa","bb"};
         String str = sArray[5]; // IndexOutOfBoundsException

         int n = 5 / 0; // ArithmeticException
        }

public void someFC (){
try{
     callFc();
    }
 catch(IndexOutOfBoundsException e){
      Log.e("TAG", e.toString());
  }
 catch(ArithmeticException e2){ 
      Log.e2("TAG",e2.toString()); 
  }
}