After entering the URL configured by tomcat, there is a status 404 error. Repeatedly search and compare, search online, and then turn over the error information (this step was realized later). Lifecycleexception error is found. After finding the solution, it is finally successful

Thanks for the blog: http://blog.csdn.net/zhenqian52/article/details/51330164

My error is the first, the servlet     The URL pattern configuration of is written with a “/” less. It is successfully started after adding it

Other mistakes will be added later   –_–,,