1. Reasons for bugs
The bug print information is as follows:
D:\Java\jdk1.8.0_261\bin\java.exe -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\IntelliJ IDEA 2020.1.3\lib\idea_rt.jar=51148:D:\IntelliJ IDEA 2020.1.3\bin" -Dfile.encoding=UTF-8 -classpath "D:\IntelliJ IDEA 2020.1.3\lib\idea_rt.jar;D:\IntelliJ IDEA 2020.1.3\plugins\junit\lib\junit5-rt.jar;D:\IntelliJ IDEA 2020.1.3\plugins\junit\lib\junit-rt.jar;D:\Java\jdk1.8.0_261\jre\lib\charsets.jar;D:\Java\jdk1.8.0_261\jre\lib\deploy.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\access-bridge-64.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\cldrdata.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\dnsns.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\jaccess.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\jfxrt.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\localedata.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\nashorn.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\sunec.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\sunjce_provider.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\sunmscapi.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\sunpkcs11.jar;D:\Java\jdk1.8.0_261\jre\lib\ext\zipfs.jar;D:\Java\jdk1.8.0_261\jre\lib\javaws.jar;D:\Java\jdk1.8.0_261\jre\lib\jce.jar;D:\Java\jdk1.8.0_261\jre\lib\jfr.jar;D:\Java\jdk1.8.0_261\jre\lib\jfxswt.jar;D:\Java\jdk1.8.0_261\jre\lib\jsse.jar;D:\Java\jdk1.8.0_261\jre\lib\management-agent.jar;D:\Java\jdk1.8.0_261\jre\lib\plugin.jar;D:\Java\jdk1.8.0_261\jre\lib\resources.jar;D:\Java\jdk1.8.0_261\jre\lib\rt.jar;D:\IdeaProjects\untitled11\untitled\untitled11\Mybatis-Study\mybatis-01\target\test-classes;D:\IdeaProjects\untitled11\untitled\untitled11\Mybatis-Study\mybatis-01\target\classes;D:\Maven\apache-maven-3.6.3-bin\apache-maven-3.6.3\maven-repo\mysql\mysql-connector-java\5.1.47\mysql-connector-java-5.1.47.jar;D:\Maven\apache-maven-3.6.3-bin\apache-maven-3.6.3\maven-repo\org\mybatis\mybatis\3.5.2\mybatis-3.5.2.jar;D:\Maven\apache-maven-3.6.3-bin\apache-maven-3.6.3\maven-repo\junit\junit\4.12\junit-4.12.jar;D:\Maven\apache-maven-3.6.3-bin\apache-maven-3.6.3\maven-repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 com.xu.dao.UserDaoTest,deleteUser
org.apache.ibatis.binding.BindingException: Type interface com.xu.dao.UserMapper is not known to the MapperRegistry.
at org.apache.ibatis.binding.MapperRegistry.getMapper(MapperRegistry.java:47)
at org.apache.ibatis.session.Configuration.getMapper(Configuration.java:779)
at org.apache.ibatis.session.defaults.DefaultSqlSession.getMapper(DefaultSqlSession.java:291)
at com.xu.dao.UserDaoTest.deleteUser(UserDaoTest.java:71)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)
Process finished with exit code -1
According to the information, the main reason for the bug is
that the resource tag is not imported into the configuration file of mybatis-config to bind the mapper, and the path needs to be used.
2. Solution:
Import the resource tag in the mybatis configuration file:
<mappers>
<mapper resource="com/xu/dao/UserMapper.xml"/>
</mappers>