int cannot be dereferenced if (root == node.data) code example

Example: int cannot be dereferenced???

Primitives (byte, char, short, int, long, float, double, boolean) are not 
objects and do not have member variables or methods. They're just simple values.
So you cannot do somePrimitive.something() . So in the above example, x is an 
int, a primitive, and therefore cannot be dereferenced - meaning x.anything is 
invalid syntax in Java.