递归实现任意个字符的排列组合

public class Demo2 {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        get("","123456");
    }
    public static void get(String arr,String str){
        if(str.length()==1){
            System.out.println(arr+str);
            
        }else{
            for(int i=0;i<str.length();i++){
                String temp = str.substring(i, i+1);
                String l=arr+temp;
                String a=str.replace(temp, "");
                get(l,a);
            }
        }
    }
}