Java8，Tomcat9.0.26，Spring全系5.2.6，MyBatis3.5.4，IDEA自带的Maven
Log4j报错
log4j在控制台输出：
log4j:ERROR A "org.apache.log4j.ConsoleAppender" object is not assignable to a "org.apache.log4j.Appender" variable.
log4j:ERROR The class "org.apache.log4j.Appender" was loaded by
log4j:ERROR [java.net.URLClassLoader@6a6824be] whereas object of type
log4j:ERROR "org.apache.log4j.ConsoleAppender" was loaded by [ParallelWebappClassLoader
context: j2eeHW0602_war_exploded
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@6a6824be
].
log4j:ERROR Could not instantiate appender named "stdout".
log4j.properties文件存放在resources下
内存泄漏
02-Jun-2020 14:57:20.437 警告 [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [j2eeHW0602_war_exploded] appears to have started a thread named [mysql-cj-abandoned-connection-cleanup] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:80)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
java.lang.Thread.run(Thread.java:745)
