Collisions... working but not.

I'm creating a lengthy program, that has a player, and an arraylist of solid objects. For each run through the program, the program checks if there is a collision between the player, and any of the object in the arraylist. If there is a collision, the program then determines the orientation of the collision from: to left, to right, to up, or to down. I only want the program to recognize one orientation of collision at a time. However, I cant seem to figure out a geometric way to prevent the program from realizing more than one collision, or the wrong type of collision.

Code Java:

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//I use these variables to assume a bounding box around objects/player.
private int xPosLeft = x;
private int xPosRight = x+Constants.width;
private int xPosUp = y;
private int xPosDown = y+Constants.height;
//A bounding box is made for every object, and the player in this fashion.

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I don't know how to explain the problem.. other than that a collision can't occur unless the player is already overlapping an object. When that happens, I simply fix up the position of the player. But it results in a 'twitchy' animation (as long as the key is pressed.) Also, if you take a minute to realize the variables, a collision to the left can also be a collision to the right... the variables may not all be parallel in structure.. because I keep changing them to figure out why I can't get it to work.

Code Java:

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//Object is to the left of the player.
	public boolean CollisiontoLeft(Player Greenman) {
		if(Greenman.xPosLeft > xPosRight) {
			CollisiontoLeft = true;
			Greenman.xPosLeft = xPosRight;
			Greenman.xPosRight = Greenman.xPosLeft + Constants.xSize;
			Greenman.gamexPos = xPosLeft+Constants.xSize/2;
			Greenman.canRight=false;
			return true;
		}
		else
			return false;
	}
	//Object is to the right of the player.
	public boolean CollisiontoRight(Player Greenman) {
		if(Greenman.xPosRight < xPosLeft) {
			CollisiontoRight = true;
			Greenman.xPosRight = xPosLeft;
			Greenman.xPosLeft = Greenman.xPosRight - Constants.xSize;
			Greenman.gamexPos = xPosLeft+Constants.xSize/2;
			Greenman.canRight=false;
			return true;
		}
		else
			Greenman.canRight=true;
			return false;
	}
	//Object is above the player.
	public boolean CollisiontoUp(Player Greenman) {
		if(Greenman.yPosDown > yPosDown) {
			CollisiontoUp = true;
			Greenman.yPosUp = yPosDown;
			Greenman.yPosDown = Greenman.yPosUp + Constants.ySize;
			Greenman.gameyPos = yPosUp+Constants.ySize/2;
			return true;
		}
		else
			return false;
	}
	//Object is below the player.
	public boolean CollisiontoDown(Player Greenman) {
		if(Greenman.yPosDown < yPosUp) {
			CollisiontoDown = true;
			Greenman.yPosDown = yPosUp;
			Greenman.yPosUp = Greenman.yPosDown - Constants.ySize;
			Greenman.gameyPos = yPosUp+Constants.ySize/2;
			return true;
		}
		else
			return false;

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Anyways.. tell me if you know how to fix this.