public class exp2{
  public exp2(){}
  public void fengjie(int n){
    for(int i=2;i<=n/2;i++){
      if(n%i==0){
        System.out.print(i+"*");
        fengjie(n/i);
        }
    }
    System.out.print(n);
    System.exit(0);///不能少这句，否则结果会出错
    }
    public static void main(String[] args){
       String str="";
       exp2 c=new exp2();
       str=javax.swing.JOptionPane.showInputDialog("请输入N的值（输入exit退出）：");
       int N;
       N=0;
       try{
           N=Integer.parseInt(str);
           }catch(NumberFormatException e){
             e.printStackTrace();
             }
      System.out.print(N+"分解质因数："+N+"=");
      c.fengjie(N);
    }  
}