凯撒密码是一种非常古老的加密方法，相传当年凯撒大地行军打仗时为了保证自己的命令不被敌军知道，就使用这种特殊的方法进行通信，以确保信息传递的安全。他的原理很简单，说到底就是字母于字母之间的替换。基于java-Caesar is a very old password encryption method, according to legend was Caesar earth war march in order to ensure that their orders will not be the enemy know that the use of this particular method of communication, in order to ensure the safety of information transmission. His principle is very simple, in the final analysis is between the letters in the alphabet to replace. Based on java