启动时会卡在：
Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
同时，关闭 tomcat会出现：
Could not contact localhost:8005. Tomcat may not be running
此时可以：
1.找到jdk地址
依次是用 which java 然后 ls -lrt /usr/java/jdk/jdk1.8.0_181/bin/java 最终得到的结果前面部分才是jdk的路径
/usr/java/jdk/jdk1.8.0_181
2.进入 /usr/java/jdk/jdk1.8.0_181/jre/lib/security/ 目录下 (cd /usr/java/jdk/jdk1.8.0_181/jre/lib/security/)
3.修改java.security （vim java.security）
4 、 将 "securerandom.source=file:/dev/random"
修改为"securerandom.source=file:/dev/./urandom"，保存退出（按esc，输入”:wq”，回车）
（在 vim 中进行文本搜索：输入”/”，再输入关键词，回车，按“n”向下查找匹配词，按“N”向上查找匹配词；
eg：输入“/securerandom.source”，回车，按“n”直到找到“securerandom.source=file:/dev/random”）
5、启动tomcat，分分钟 shutdown、startup。
未修改前：
修改后：
转自：
https://blog.csdn.net/qq_34693599/article/details/81115977
https://img-blog.csdn.net/20180719155339256?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0NjkzNTk5/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70