Intellij IDEA Tomcat 启动报错, Unable to ping server at localhost 1099

Tomcat版本与jdk版本不匹配导致的。

我这是jdk9和Tomcat7组合启动造成的。

以下是Tomcat官方提供的版本对应关系：

Servlet Spec	JSP Spec	EL Spec	WebSocket Spec	JASPIC Spec	Apache Tomcat Version	Latest Released Version	Supported Java Versions
4.0	2.3	3.0	1.1	1.1	9.0.x	9.0.6	8 and later
3.1	2.3	3.0	1.1	1.1	8.5.x	8.5.29	7 and later
3.1	2.3	3.0	1.1	N/A	8.0.x (superseded)	8.0.50 (superseded)	7 and later
3.0	2.2	2.2	1.1	N/A	7.0.x	7.0.85	6 and later (7 and later for WebSocket)
2.5	2.1	2.1	N/A	N/A	6.0.x (archived)	6.0.53 (archived)	5 and later
2.4	2.0	N/A	N/A	N/A	5.5.x (archived)	5.5.36 (archived)	1.4 and later
2.3	1.2	N/A	N/A	N/A	4.1.x (archived)	4.1.40 (archived)	1.3 and later
2.2	1.1	N/A	N/A	N/A	3.3.x (archived)	3.3.2 (archived)	1.1 and later

版本关系来源： http://tomcat.apache.org/whichversion.html

参考：https://blog.youkuaiyun.com/wsm0712syb/article/details/52495034