啓動tomcat時，一直卡在
root@iz8vbdzx7y7owm488t4d89z bin]# tail -f ../logs/catalina.out
09-Jun-2017 15:57:06.666 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["ajp-nio-8009"]
09-Jun-2017 15:57:06.667 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
09-Jun-2017 15:57:06.667 INFO [main] org.apache.catalina.startup.Catalina.load Initialization processed in 535 ms
09-Jun-2017 15:57:06.684 INFO [main] org.apache.catalina.core.StandardService.startInternal Starting service Catalina
09-Jun-2017 15:57:06.684 INFO [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/8.0.15
09-Jun-2017 15:57:06.690 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory /opt/apache-tomcat-8.0.15-server/webapps/ROOT
的解決辦法：
永久：oracle 說修改 $JAVA_HOME/jre/lib/security/java.security 文件，替換securerandom.source=file:/dev/random 爲 securerandom.source=file:/dev/urandom。對所有使用JVM的應用生效。（這個永久的方法，這裏面有個問題，就是設置時候實際應該設置爲securerandom.source=file:/dev/./urandom，否則不生效）
可參考一下鏈接內容：https://blog.csdn.net/njchenyi/article/details/46641141?utm_source=copy