Debugging movement/collision code in 2d tile game

Newbie & Debugging Questions
#1

Hello, I’m working on a top down 2d game and am having some problems with collision detection. Here is a basic screenshot.

https://dl.dropboxusercontent.com/u/24222531/game1.png

My issue involves buggy movement. If I spam movement keys near a wall, I can pass through and get stuck. I think my problem may be related to multiple threads, but I am not sure.

I have a text file grid of integers read in for collision, 1 = not passable, 0 = passable. My checkCollision function checks the proposed new player position for a collision, and disallows that movement if there is a tile.

I use a overridden Keymanager classhttp://pastebin.java-gaming.org/b9854254086 to alter Player’s public variables UP, DOWN, LEFT, RIGHT to transfer keyboard to game logic.

Here is the player tick class:


public class Player {
**SNIP SNIP**
public void tick() {
        if (moving) {
            updatePlayerPosition();
        }

        if (sprinting) {
            moveSpeed = SPRINT; // 16
        } else {
            moveSpeed = WALK; // 8
        }

        if (!moving) {
            if (up) {
                moveUp();
            }
            if (down) {
                moveDown();
            }
            if (right) {
                moveRight();
            }
            if (left) {
                moveLeft();
            }

        }

Here I update the player movement if they are still in the process of moving from one tile to another. http://pastebin.java-gaming.org/9854530468e

private void updatePlayerPosition() {
       
        switch (facing) {
            case "north":
                if (!detectCollision(tileX, tileY - 1)) {
                    northAnimator.update(System.currentTimeMillis());
                    y -= moveSpeed;
                    if (y % 32 == 0) {
                        moving = false;
                        tileY = (int) pixelsToTileY(y);
                    }
                }
                break;
            case "south":
*SNIPSNIP*
        }
    }

This simply changes facing direction, sets moving to true, and lets the above method handle the rest. http://pastebin.java-gaming.org/4506e684f89

private void moveUp() { // move player up
        // if not facing north, make facing north

        if (!facing.equals("north")) {
            facing = "north";
        } else {

            // else, detect collision in the direction            
            if (!detectCollision(tileX, tileY - 1)) {
                moving = true;
            }
        }
    }

Somewhere in here there is a bug going on. I know the detectcollision method is working properly as I debugged it with println’s. It seems that sometimes, while I am actively “Moving”, my direction can change and place me in a wall. Note that this code has double collision checking, I tried with one and it simply let me into impassable walls, with two checks i actually get stuck in the wall and cant move at all.

Can anyone help me out here. Is there a simpler way of getting animated tile movement?