Java randomization – (minus sign) and (plus sign)

Is there any way to add a plus or minus sign randomly? I have a program in which an elf moves on the screen. When you click it, it will reappear in another place I also hope it moves in a random direction At present, I can only set it to move from left to right, or from right to left –

private int x = random.nextInt(150); 
    private int y = random.nextInt(500);    
    private int xSpeed = random.nextInt(10);//Horizontal increment of position (speed)
    private int ySpeed = random.nextInt(10);// Vertical increment of position (speed)

public void update() {
        x = x +- xSpeed;
        y = y +- ySpeed;
}

Solution

You can make a variant at any time:

xSpeed = xSpeed * ( random.nextBoolean() ? 1 : -1 );
ySpeed = ySpeed * ( random.nextBoolean() ? 1 : -1 );