如何避免java中重复的代码？

I'm just beginner in programming. uf is a union-find class with the method union which connects the roots of two node. This piece of code is responsible for opening a site of a grid and union the site with its neighbor if any of neighbor is opened. And if one of its neighbors is full, then fill all nodes that connected with the site. This is the actual code:I'm just beginner in programming. uf is a union