通过dump 线程和jvisualVM 采样发现 org.nutz.lang.random.R.UU32 耗时占比较高。
jdk:Java(TM) SE Runtime Environment (build 8.0.5.36 - pxz6480sr5fp36-20190510_01(SR5 FP36))
IBM J9 VM (build 2.9, JRE 1.8.0 Linux s390x-64-Bit Compressed References 20190502_415899 (JIT enabled, AOT enabled)
启动项： -Djava.security.egd=file:/dev/./urandom

"QuartzScheduler_Worker-95" - Thread t@129
   java.lang.Thread.State: BLOCKED
        at java.security.SecureRandom.nextBytes(SecureRandom.java:471)
        - waiting to lock <4504d3ef> (a java.security.SecureRandom) owned by "QuartzScheduler_Worker-84" t@118
        - locked <4504d3ef> (a java.security.SecureRandom)
        at java.util.UUID.randomUUID(UUID.java:156)
        at org.nutz.lang.random.R.UU32(R.java:140)
        at org.nutz.dao.DaoInterceptorChain.<init>(DaoInterceptorChain.java:51)
        at org.nutz.dao.impl.DaoSupport._exec(DaoSupport.java:248)
        at org.nutz.dao.impl.NutDao.query(NutDao.java:482)
        at org.nutz.dao.impl.NutDao.query(NutDao.java:487)