Stuck at “Shark -> SharkExampleJSP ready and waiting”

OS: Ubuntu 16.04.3 LTS
Java: OpenJDK 1.8.0_181

Thread Dump:
"localhost-startStop-1" #16 daemon prio=5 os_prio=0 tid=0x00007f9224004000 nid=0xccc runnable [0x00007f92724b5000]
java.lang.Thread.State: RUNNABLE
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:255)
at sun.security.provider.SeedGenerator$URLSeedGenerator.getSeedBytes(SeedGenerator.java:539)
at sun.security.provider.SeedGenerator.generateSeed(SeedGenerator.java:144)
at sun.security.provider.SecureRandom$SeederHolder.(SecureRandom.java:203)
at sun.security.provider.SecureRandom.engineNextBytes(SecureRandom.java:221)
- locked (a sun.security.provider.SecureRandom)
at java.security.SecureRandom.nextBytes(SecureRandom.java:468)
at java.security.SecureRandom.next(SecureRandom.java:491)
at java.util.Random.nextInt(Random.java:329)
at org.apache.catalina.util.SessionIdGeneratorBase.createSecureRandom(SessionIdGeneratorBase.java:237)
at org.apache.catalina.util.SessionIdGeneratorBase.getRandomBytes(SessionIdGeneratorBase.java:174)
at org.apache.catalina.util.StandardSessionIdGenerator.generateSessionId(StandardSessionIdGenerator.java:34)
at org.apache.catalina.util.SessionIdGeneratorBase.generateSessionId(SessionIdGeneratorBase.java:167)
at org.apache.catalina.util.SessionIdGeneratorBase.startInternal(SessionIdGeneratorBase.java:256)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)

To check for available entropy:
sudo cat /proc/sys/kernel/random/entropy_avail

Solution:
apt-get install haveged
update-rc.d haveged defaults

• https://www.techrepublic.com/article/how-to-add-more-entropy-to-improve-cryptographic-randomness-on-linux/
• https://www.digitalocean.com/community/tutorials/how-to-setup-additional-entropy-for-cloud-servers-using-haveged
• https://serverfault.com/questions/172337/explain-in-plain-english-about-entropy-available