编写一个java应用程序。用户从键盘输入一个1-9999之间的数，程序将判断这个数是几位数，并判断这个数是否回文数。回文数是指将数含有的数字逆序排列后得到的数和原数相同，例如12121,4224,6778776等都是回文数。-Write a java application. The user from the keyboard to enter a number between 1-9999, the program will determine whether this number is a few number, and determine whether the number of palindromic number in this. Palindromic number refers to the number containing the number of reverse arrangement obtained after the same number and the original number, for example, are all 12121,4224,6778776 palindromic number.