递归分解质因数

public class Java {
	static boolean isSu(int a){
		for(int i =2;i < Math.sqrt(a);i++){
			if (a%i==0){
				return false;
			}
		}
		return true;
	}
	static void printer(int a ){
		if((isSu(a)==true)&&a>=2){
			System.out.println(a);
		}else{
			int i =a;
			for(;i>=2;){
				if(!(isSu(--i)&&(a%i==0)))
					continue;
				System.out.println(i);
				break;
			}
			printer(a/i);
		}
	}
	public static void main(String[] strs){
		System.out.println(isSu(15));
		printer(20);
	}
}