具体错误信息

"C:\Program Files (x86)\Java\jdk1.8.0_291\bin\java.exe" -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:13766,suspend=y,server=n -ea -Didea.test.cyclic.buffer.size=1048576 -javaagent:C:\Users\HL\.IntelliJIdea2019.2\system\captureAgent\debugger-agent.jar -Dfile.encoding=UTF-8 -classpath "D:\soft\IDEA\IntelliJ IDEA 2019.2.3\lib\idea_rt.jar;D:\soft\IDEA\IntelliJ IDEA 2019.2.3\plugins\junit\lib\junit-rt.jar;D:\soft\IDEA\IntelliJ IDEA 2019.2.3\plugins\junit\lib\junit5-rt.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\charsets.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\deploy.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\access-bridge-32.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\cldrdata.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\dnsns.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\jaccess.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\jfxrt.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\localedata.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\nashorn.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\sunec.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\sunjce_provider.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\sunmscapi.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\sunpkcs11.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\ext\zipfs.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\javaws.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\jce.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\jfr.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\jfxswt.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\jsse.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\management-agent.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\plugin.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\resources.jar;C:\Program Files (x86)\Java\jdk1.8.0_291\jre\lib\rt.jar;D:\soft\Projectidea\pro-ssm\Pro01-mybatis-begin-Practice\target\test-classes;D:\soft\Projectidea\pro-ssm\Pro01-mybatis-begin-Practice\target\classes;D:\soft\Maven\MavenRepository\org\mybatis\mybatis\3.5.7\mybatis-3.5.7.jar;D:\soft\Maven\MavenRepository\junit\junit\4.12\junit-4.12.jar;D:\soft\Maven\MavenRepository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;D:\soft\Maven\MavenRepository\mysql\mysql-connector-java\5.1.3\mysql-connector-java-5.1.3.jar" com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.atguigu.mybatis.dao.Impl.PersonMapperImplTest,test01_insert
Connected to the target VM, address: '127.0.0.1:13766', transport: 'socket'




org.apache.ibatis.exceptions.PersistenceException: 
### Error updating database.  Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 0 ms ago.
### The error may exist in mapper/PersonMapper.xml
### The error may involve com.atguigu.mybatis.mapper.PersonMapperImpl.addPerson
### The error occurred while executing an update
### Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 0 ms ago.

    at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:196)
    at org.apache.ibatis.session.defaults.DefaultSqlSession.insert(DefaultSqlSession.java:181)
    at com.atguigu.mybatis.mapper.PersonMapperImpl.addPerson(PersonMapperImpl.java:28)
    at com.atguigu.mybatis.dao.Impl.PersonMapperImplTest.test01_insert(PersonMapperImplTest.java:13)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

一般是由于jdbc.propreties配置文件里面有错误，

按照正常修改一下即可

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///persondb?useUnicode=true&characterEncoding=utf-8&useSSL=false
jdbc.username=root
jdbc.pwd=root