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. User from the keyboard to enter a number between 1-9999, the program will determine this number is several numbers and determine whether the number of palindrome. Refers to the number of palindromic numbers in reverse order with the number and the original post to get the same number, for example 12121,4224,6778776 are all palindrome.