JAVA输入一个整数，求出其所有质因数

首先得求出能整除A的数，再判断I是否是质数！！！
import java.util.*;
public class aa {
public static void main(String[] args) {
System.out.println("Please input the number:");
Scanner in=new Scanner(System.in);
int a;
a=in.nextInt();
if(a==1||a==0)
System.out.println("Sorry,it don't have prime number!");
else
{
System.out.print(" prime number is:");
for(int i=2;i<=a;i++)
{
if(a%i==0)
{
if(IsPrime(i)==false)
System.out.print(" ");
else
System.out.print(i+" ");
}
}
}
}
public static boolean IsPrime(int i)
{
if(i==2||i==3)
return true;
else
{
for(int k=2;k<=java.lang.Math.sqrt(i);k++)
{
if (i%k==0)
return false;
}
return true;
}
}
}