Path Following Algorithm for Entity
Method getXDifference and getYDifference are very similar, you can convert this into a single method that accepts two variables. 
you could also inline the return statement as the method name is sufficient to tell what it is returning.
Instead of calculating pastX and pastY, you can write methods to return the computed value.

boolean isPastX(variables...){
    // logic to calculate pastX and return it.
}


and the if statement will turn into if( isPastX() &amp;&amp; isPastY()).
This will also help in short-circuiting the condition in case calculating pastX or pastY is very expensive(it isn't in this example, just a suggestion).
Curly braces {} should always be used after conditional statements or loops, even it's just a single line. It may avoid confusion in some scenarios.

if (getPath().size == 0){
    return;
}