递归算法是一种直接或者间接调用自身函数或者方法的算法。Java递归算法是基于Java语言实现的递归算法。递归算法的实质是把问题分解成规模缩小的同类问题的子问题，然后递归调用方法来表示问题的解。(Recursive algorithm is an algorithm that directly or indirectly calls its own function or method. Java recursive algorithm is based on the Java language recursive algorithm. The essence of the recursive algorithm is to decompose the problem into sub-problems of the same type of problem of reduced scale, and then recursively call the method to represent the solution of the problem.)