"/dev/random" hangs in java program when server is inactive

Issue

• Reading "/dev/random" hangs in java program
• entropy is too low to generate enough random numbers

• Java program hangs as it's waiting on a thread that's continuously in this state trying to generate random numbers:

      "main" prio=10 tid=0x00002aab580e2000 nid=0x6c98 runnable [0x000000004044f000]
         java.lang.Thread.State: RUNNABLE
           at java.io.FileInputStream.readBytes(Native Method)
           at java.io.FileInputStream.read(FileInputStream.java:199)
           at sun.security.provider.NativePRNG$RandomIO.readFully(NativePRNG.java:185)
           at sun.security.provider.NativePRNG$RandomIO.implGenerateSeed(NativePRNG.java:202)
           - locked <0x00002aaad23739a0> (a java.lang.Object)
           at sun.security.provider.NativePRNG$RandomIO.access$300(NativePRNG.java:108)
           at sun.security.provider.NativePRNG.engineGenerateSeed(NativePRNG.java:102)
           at java.security.SecureRandom.generateSeed(SecureRandom.java:495)