MyBatis相关bug的记录

对于MyBatis的学习，从最开始就遇到了许多莫名其妙的bug！经过了百度和弹幕也没有解决，后来自己莫名奇妙的改反而对了。 先看bug：

"D:\SoftWare\Idea\IntelliJ IDEA 2020.3.2\jbr\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\SoftWare\Idea\IntelliJ IDEA 2020.3.2\lib\idea_rt.jar=54216:D:\SoftWare\Idea\IntelliJ IDEA 2020.3.2\bin" -Dfile.encoding=UTF-8 -classpath "D:\SoftWare\Idea\IntelliJ IDEA 2020.3.2\lib\idea_rt.jar;D:\SoftWare\Idea\IntelliJ IDEA 2020.3.2\plugins\junit\lib\junit5-rt.jar;D:\SoftWare\Idea\IntelliJ IDEA 2020.3.2\plugins\junit\lib\junit-rt.jar;D:\Desktop\MyBatis02\mybatis-02\target\test-classes;D:\Desktop\MyBatis02\mybatis-02\target\classes;D:\Environment\apache-maven-3.8.1\maven-repo\mysql\mysql-connector-java\5.1.47\mysql-connector-java-5.1.47.jar;D:\Environment\apache-maven-3.8.1\maven-repo\org\mybatis\mybatis\3.5.2\mybatis-3.5.2.jar;D:\Environment\apache-maven-3.8.1\maven-repo\junit\junit\4.13.2\junit-4.13.2.jar;D:\Environment\apache-maven-3.8.1\maven-repo\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar" com.intellij.rt.junit.JUnitStarter -ideVersion5 -junit4 com.lxz.dao.UserDaoTest,getUserLike

java.lang.ExceptionInInitializerError
	at com.lxz.dao.UserDaoTest.getUserLike(UserDaoTest.java:14)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)
Caused by: org.apache.ibatis.exceptions.PersistenceException: 
### Error building SqlSession.
### Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 11; columnNumber: 9; 1 字节的 UTF-8 序列的字节 1 无效。
	at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:80)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:64)
	at com.lxz.utils.MybatisUtils.<clinit>(MybatisUtils.java:21)
	... 26 more
Caused by: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: org.xml.sax.SAXParseException; lineNumber: 11; columnNumber: 9; 1 字节的 UTF-8 序列的字节 1 无效。
	at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:260)
	at org.apache.ibatis.parsing.XPathParser.<init>(XPathParser.java:126)
	at org.apache.ibatis.builder.xml.XMLConfigBuilder.<init>(XMLConfigBuilder.java:81)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:77)
	... 28 more
Caused by: org.xml.sax.SAXParseException; lineNumber: 11; columnNumber: 9; 1 字节的 UTF-8 序列的字节 1 无效。
	at java.xml/com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:204)
	at java.xml/com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:178)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:306)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3085)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:605)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:534)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:888)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:824)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:246)
	at java.xml/com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
	at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:258)
	... 31 more
Caused by: com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: 1 字节的 UTF-8 序列的字节 1 无效。
	at java.xml/com.sun.org.apache.xerces.internal.impl.io.UTF8Reader.invalidByte(UTF8Reader.java:702)
	at java.xml/com.sun.org.apache.xerces.internal.impl.io.UTF8Reader.read(UTF8Reader.java:568)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLEntityScanner.load(XMLEntityScanner.java:1904)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLEntityScanner.scanData(XMLEntityScanner.java:1377)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLScanner.scanComment(XMLScanner.java:800)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanComment(XMLDocumentFragmentScannerImpl.java:1069)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2898)
	... 39 more


Process finished with exit code -1

首先，对于读bug。在idea中都应该倒着读，从下往上读。看着cause by的那一行即可。对于上述的报错，****只需要将mybatis的接口映射文件和配置文件中的中文注释去掉即可，也可以将编码方式encoding改为utf8。

关于.properties文件的优先级（补充）

在之前我们就知道可以通过properties属性来实现引用配置文件：Mybatis官方文档所给的引用配置文件代码是：

	<!--引入外部配置文件-->
    <properties resource="db.properties">
        <property name="username" value="root"/>
        <property name="pwd" value="123123"/>
    </properties>

我们也可以将引入配置文件的代码写为：

<properties resource="db.properties"/>

这样写的前提是我们的资源文件里面包含了 name以及pwd属性！当我们采用了官方给的引入配置文件的方式但是又在外部配置文件写了name以及pwd属性，idea会自动的以外部的文件为标准执行代码。