坑-but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread

在测试环境中遇到启动 tomcat8.x时报错，解决思路：

 07-Sep-2020 19:09:11.196 WARNING [localhost-startStop-1] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [system] appears to have started a thread named [pool-1-thread-4] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 sun.misc.Unsafe.park(Native Method)
 java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
 java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
 java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
 java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 java.lang.Thread.run(Thread.java:748)

问了度娘，基本没有找到想要的答案！
有的说是线程池未设置大小问题
有的说是jdbc没有释放连接问题

我的遇到情况是 jar包缺失+ jar包内部引用变量未给定确切的值的问题，造成启动的时候直接整个tomcat容器起为来！

总结：一般地 都是jar包依赖缺失引起的！当遇到以上问题，请仔细检查你的java引用！