JDK version problem supported by Tomcat in WeChat development

When WeChat develops the QR code module to call the interface of WeChat, it starts Tomcat and finds that it will report an error and forget to report what error seems to be can't ...... and so on. This is the need to change the JDK version to version 1.7, which does not support the version below 1.7 version of JDK, and the port number of Tomcat currently supports 80.