版权声明：柠檬乐园：200145783 https://blog.csdn.net/u014431237/article/details/84776761
进到jdk目录
keytool -genkey -keyalg RSA -validity 天数 -alias appcan -keystore 别名.keystore
keytool -genkey -keyalg RSA -validity 20000 -alias appcan -keystore myapp.keystore
