求助：java里的InputData找不到符号

红色那一行编译不过：InputData找不到符号源代码如下：
import java.io.*;
public class Menu{
        public Menu(){
                while (true){
                        this.show();
                }
        }
        public void show(){
                System.out.println("=========System==========");
                System.out.println(" [1].add");
                System.out.println(" [2].delete");
                System.out.println(" [3].update");
                System.out.println(" [4].find");
                System.out.println(" [0].exit");
                InputData input = new InputData();
                int i = input.getInt("Pls choose");
                switch (i){
                        case 1:{
                                Operate.add();
                                break;
                        }
                        case 2:{
                                Operate.delete();
                                break;
                        }
                        case 3:{
                                Operate.update();
                                break;
                        }
                        case 4:{
                                Operate.find();
                                break;
                        }
                        case 0:{
                                System.exit(1);
                                break;
                        }
                        default:{
                                System.out.println("Pls choose zhengquede");
                        }
                }
        }       
}