Designing classes - Objects First with Java: A Practical Introduction Using BlueJ - page 208

Code 6.4
Using an accessor
method to decrease
coupling

public class Room
{

private String description;
private Room northExit;
private Room southExit;
private Room eastExit;
private Room westExit;

// existing methods unchanged

public Room getExit(String direction)
{

if (direction.equals( "north" )) {
return northExit;

}
if (direction.equals( "east" )) {
return eastExit;

}
if (direction.equals( "south" )) {
return southExit;

}
if (direction.equals( "west" )) {
return westExit;

}
return null ;

}

}

Having made this change to the Room class, we need to change the Game class as well.
Wherever an exit variable was accessed, we now use the accessor method. For example,
instead of writing

nextRoom = currentRoom.eastExit;

we now write

nextRoom = currentRoom.getExit("east");

This makes coding one section in the Game class much easier as well. In the goRoom method,
the replacement suggested here will result in the following code segment:

Room nextRoom = null;
if(direction.equals("north")) {
nextRoom = currentRoom.getExit("north");
}
if(direction.equals("east")) {
nextRoom = currentRoom.getExit("east");
}