Space invader/Breakout

alien.java

package com.mygdx.game;

import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;


public class alien {

    public void setCollum(int collum) {
        Collum = collum;
    }

    int Collum;

    public Sprite getSprite() {
        return sprite;
    }

    public void setSprite(Sprite sprite) {
        this.sprite = sprite;
    }

    Sprite sprite;


    public alien(int collum,Texture texture){
        sprite = new Sprite(texture);
        sprite.setSize(32,32);
        Collum = collum;

    }
    int getCollum(){
        return Collum;
    }
}

MyGdxGame.java

package com.mygdx.game;

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.Vector2;
import com.mygdx.game.alien;


public class MyGdxGame extends ApplicationAdapter {
    SpriteBatch batch;
    Texture img;
    Sprite Paddle;
    Sprite ball;
    alien[] Aliens;
    int row;
    int collum;
    int x;
    int y;
    int targetY;
    float direction;
    Vector2 ballDirection;
    int paddleVel;
    boolean locked;

    @Override
    public void create() {

        locked = true;
        paddleVel = 0;
        ballDirection = new Vector2(0, -3);
        direction = 1;
        x = 0;
        y = 1;
        row = 0;
        collum = 0;
        batch = new SpriteBatch();
        img = new Texture("badlogic.jpg");
        Paddle = new Sprite(img);
        Paddle.setSize(128, 8);
        Paddle.setPosition(Gdx.graphics.getWidth() / 2, 8);
        ball = new Sprite(img);
        ball.setSize(16, 16);
        ball.setPosition(Gdx.graphics.getWidth() / 2, Gdx.graphics.getHeight() / 2);
        Aliens = new alien[50];

        for (int i = 0; i < 50; i++) {
            Aliens[i] = new alien(collum, img);

            Aliens[i].getSprite().setPosition(row * Aliens[i].getSprite().getWidth() + 2 * row + 128, Gdx.graphics.getHeight() - y * 32 - collum * 34);
            row++;
            if (row > 10) {
                row = 0;
                collum++;
            }


        }
    }

    @Override
    public void render() {
        Gdx.gl.glClearColor(0, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
        batch.begin();
        for (alien Alien : Aliens) {
            if (Alien.getSprite().getTexture() != null) Alien.getSprite().draw(batch);
        }
        Paddle.draw(batch);
        ball.draw(batch);

        batch.end();
        updateAliens();
        updatePaddle();
        updateBall();
    }

    void paddleCollision() {
        if (ball.getBoundingRectangle().overlaps(Paddle.getBoundingRectangle())) {
            ballDirection.y *= -1;
            ballDirection.x += paddleVel / 4;
        }

    }

    void updateBall() {
        if (!locked) {


            ball.setPosition(ball.getX() + ballDirection.x, ball.getY() + ballDirection.y);
            if (ball.getX() < 0 || ball.getX() > Gdx.graphics.getWidth()) {
                ballDirection.x *= -1;
            }

            if (ball.getY() < 0 || ball.getY() > Gdx.graphics.getHeight()) {
                ball.setPosition(Paddle.getX() + Paddle.getWidth() / 2, Paddle.getY() + Paddle.getHeight() + 2);
                locked = true;

            }

            for (alien Alien : Aliens) {
                if (Alien.getSprite() != null) {
                    if (ball.getBoundingRectangle().overlaps(Alien.getSprite().getBoundingRectangle())) {
                        if (ball.getY() > Alien.getSprite().getY() && ball.getY() < Alien.getSprite().getY() + Alien.getSprite().getHeight()) {
                            ballDirection.x *= -1;
                        } else {
                            ballDirection.y *= -1;
                            ball.setPosition(ball.getX(), ball.getY() + ballDirection.y);
                        }
                        Sprite sprite = new Sprite();
                        sprite.setPosition(Gdx.graphics.getWidth() / 2, Gdx.graphics.getHeight());
                        Alien.getSprite().set(sprite);
                        Alien.setCollum(-1000);

                    }
                }
            }
        } else {
            ball.setPosition(Paddle.getX() + Paddle.getWidth() / 2, Paddle.getY() + Paddle.getHeight() + 2);
        }
    }

    void updatePaddle() {
        paddleCollision();
        if (Gdx.input.isKeyPressed(Input.Keys.RIGHT)) {

            paddleVel += 1;

        }
        if (Gdx.input.isKeyPressed(Input.Keys.LEFT)) {

            paddleVel -= 1;
        }

        if (!Gdx.input.isKeyPressed(Input.Keys.LEFT) && !Gdx.input.isKeyPressed(Input.Keys.RIGHT)) {
            paddleVel = 0;
        }

        if (Paddle.getX() + paddleVel > 0 && Paddle.getX() + paddleVel + Paddle.getWidth() < Gdx.graphics.getWidth())
            Paddle.setPosition(Paddle.getX() + paddleVel, Paddle.getY());
        if (Gdx.input.isKeyPressed(Input.Keys.SPACE)) {
            ballDirection.x += paddleVel;
            locked = false;
        }
    }

    void updateAliens() {
        for (alien Alien : Aliens) {
            if (Alien.getSprite() != null) {
                if (Alien.getCollum() % 2 != 0) {
                    targetY = Gdx.graphics.getHeight() - y * 32 - Alien.getCollum() * 34;
                    Alien.getSprite().setPosition(Alien.getSprite().getX() + direction / 4, Alien.getSprite().getY() + (targetY - Alien.getSprite().getY()) * 0.1f);

                } else {
                    targetY = Gdx.graphics.getHeight() - y * 32 - Alien.getCollum() * 34;
                    Alien.getSprite().setPosition(Alien.getSprite().getX() - direction / 4, Alien.getSprite().getY() + (targetY - Alien.getSprite().getY()) * 0.1f);
                }

                if (Alien.getSprite().getX() > Gdx.graphics.getWidth() || Alien.getSprite().getX() < 0) {
                    direction *= -1;
                    y++;
                }
            }
        }
    }
}