In addition to the implementation of the code, the programmer should be concerned about the running environment of the program and the version of the tool used. Using the same framework, the same code may not be applicable to the new version of the framework, so the learning content is only for reference.
(1) The version used for struts2 learning is 2.3.31 is the last stable version of 2.3
(2) jdk version number 1.7.0_80
(3) The version number of tomcat used by the web container is 7.0.68