Jmeter 执行Java 请求时，运行结束后报错，
Tidying up remote @ Mon Feb 24 19:42:34 CST 2020 (1582544554083)
... end of run
The JVM should have exited but did not.
The following non-daemon threads are still running (DestroyJavaVM is OK):
Thread[Thread-6,5,RMI Runtime], stackTrace:freemarker.core.BuiltIn#<clinit> at line:141
freemarker.core.FMParser#BuiltIn at line:1196
freemarker.core.FMParser#PrimaryExpression at line:594
freemarker.core.FMParser#UnaryExpression at line:706
freemarker.core.FMParser#MultiplicativeExpression at line:821
freemarker.core.FMParser#AdditiveExpression at line:773
freemarker.core.FMParser#RangeExpression at line:953
freemarker.core.FMParser#RelationalExpression at line:901
freemarker.core.FMParser#EqualityExpression at line:864
freemarker.core.FMParser#AndExpression at line:1020
freemarker.core.FMParser#OrExpression at line:1042
freemarker.core.FMParser#Expression at line:551
freemarker.core.FMParser#List at line:1747
freemarker.core.FMParser#FreemarkerDirective at line:3426
freemarker.core.FMParser#MixedContentElements at line:3812
freemarker.core.FMParser#Root at line:4458
freemarker.template.Template#<init> at line:253
freemarker.cache.TemplateCache#loadTemplate at line:549
freemarker.cache.TemplateCache#getTemplateInternal at line:439
freemarker.cache.TemplateCache#getTemplate at line:292
freemarker.template.Configuration#getTemplate at line:2750
freemarker.template.Configuration#getTemplate at line:2599
org.apache.jmeter.report.dashboard.TemplateVisitor#visitFile at line:113
org.apache.jmeter.report.dashboard.TemplateVisitor#visitFile at line:49
java.nio.file.Files#walkFileTree at line:2670
java.nio.file.Files#walkFileTree at line:2742
org.apache.jmeter.report.dashboard.HtmlTemplateExporter#export at line:509
org.apache.jmeter.report.dashboard.ReportGenerator#exportData at line:381
org.apache.jmeter.report.dashboard.ReportGenerator#generate at line:262
org.apache.jmeter.JMeter$ListenToTest#generateReport at line:1324
org.apache.jmeter.JMeter$ListenToTest#run at line:1308
java.lang.Thread#run at line:748
原因：在执行java请求时会在jmeter线程之外，另外启动java线程，导致在脚本执行结束时JVM无法退出。
若要避免这种现象，需要修改jmeter.properties 中的jmeterengine.force.system.exit=true
