Hello, so I figured out how to embed Jars if anyone remembers that dilemma XD

Anyways I'm creating a top down RPG-ish sort of thing and have been wondering what the most efficient way of creating impassable blocks is. I have created my own code that works, sorta:

Class Player
Java Code:
//Called to update the position of the player's position and rectangle
public void move(boolean left, boolean right, boolean up, boolean down)
		rect = new Rectangle(x, y, w, h);
			x -= speed;
			x += speed;
			y += speed;
			y -= speed;
//Called to pass down "legacy" positions.
	public void updateP()

		px2 = px;
		py2 = py;
		px = x;
		py = y;

Class Main
Java Code:
//Updating "legacy" positions of player.
//Updating current position and rectangle of player.
			p.move(kb.left, kb.right, kb.up, kb.down);
		//Detects collisions between Player and blocks	
			for(int i = 0; i < block1[0].length; i++)
				for(int j = 0; j < block1[1].length; j++)


//Sets the player's position to what it was two cycles ago.
			p.x = p.px2;
			p.y = p.py2;

The problem is that it vibrates a bit when you try to walk into a wall. It isn't really too big of a problem, but I was guessing there was a better way.