The error may exist in mapping/StudentMapper.xml

错误日志：

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException: 
### Error building SqlSession.
### The error may exist in mapping/StudentMapper.xml
### The error occurred while processing mapper_resultMap[personMap]_association[card]
### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.io.IOException: Could not find resource mapping/StudentMapper.xml
	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.dragon.mydemo.App.main(App.java:22)
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.io.IOException: Could not find resource mapping/StudentMapper.xml
	at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:121)
	at org.apache.ibatis.builder.xml.XMLConfigBuilder.parse(XMLConfigBuilder.java:98)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:78)
	... 2 more
Caused by: java.io.IOException: Could not find resource mapping/StudentMapper.xml
	at org.apache.ibatis.io.Resources.getResourceAsStream(Resources.java:114)
	at org.apache.ibatis.io.Resources.getResourceAsStream(Resources.java:100)
	at org.apache.ibatis.builder.xml.XMLConfigBuilder.mapperElement(XMLConfigBuilder.java:371)
	at org.apache.ibatis.builder.xml.XMLConfigBuilder.parseConfiguration(XMLConfigBuilder.java:119)
	... 4 more

这是我在研究MyBatis时遇到的错误，其实是maven自身约定的问题，maven约定大于配置。

也就是说如果你的一些配置不写在自带的resources目录下，他就找不到，就会报这个错。即使你在配置里指定的稳稳当当没任何毛病也不行！！

maven由于他的约定大于配置，我们之后可以能遇到我们写的配置文件，无法被导出或者生效的问题，解决方案：

    
        
            
                src/main/resources
                
                    **/*.properties
                    **/*.xml
                
                true
            
            
                src/main/java
                
                    **/*.properties
                    **/*.xml
                
                true
            
        
    

（说到底配置文件最好还是放到resources目录下，没那么多问题了！）

我在这么配置之后又出现一个错误：2 字节的 UTF-8 序列的字节 2 无效

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException: 
### Error building SqlSession.
### Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: 2 字节的 UTF-8 序列的字节 2 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.dragon.mydemo.App.main(App.java:22)
Caused by: org.apache.ibatis.builder.BuilderException: Error creating document instance.  Cause: com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: 2 字节的 UTF-8 序列的字节 2 无效。
	at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:260)
	at org.apache.ibatis.parsing.XPathParser.(XPathParser.java:126)
	at org.apache.ibatis.builder.xml.XMLConfigBuilder.(XMLConfigBuilder.java:81)
	at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:77)
	... 2 more
Caused by: com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: 2 字节的 UTF-8 序列的字节 2 无效。
	at com.sun.org.apache.xerces.internal.impl.io.UTF8Reader.invalidByte(UTF8Reader.java:701)
	at com.sun.org.apache.xerces.internal.impl.io.UTF8Reader.read(UTF8Reader.java:372)
	at com.sun.org.apache.xerces.internal.impl.XMLEntityScanner.load(XMLEntityScanner.java:1895)
	at com.sun.org.apache.xerces.internal.impl.XMLEntityScanner.scanData(XMLEntityScanner.java:1375)
	at com.sun.org.apache.xerces.internal.impl.XMLScanner.scanComment(XMLScanner.java:801)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanComment(XMLDocumentFragmentScannerImpl.java:1034)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:899)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:842)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:771)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
	at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)
	at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
	at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:258)
	... 5 more

是前面添加的resources里一个参数true改为false

    
        
            
                src/main/resources
                
                    **/*.properties
                    **/*.xml
                
                false
            
            
                src/main/java
                
                    **/*.properties
                    **/*.xml
                
                false
            
        
    

网上搜集发现关于这个配置的其他说法（作用）：

**/*这样的写法，是为了保证各级子目录下的资源文件被打包。

MAVEN项目标准的目录结构：

一般情况下，我们用到的资源文件（各种xml，properites，xsd文件等）都放在src/main/resources下面，利用maven打包时，maven能把这些资源文件打包到相应的jar或者war里。

有时候，比如mybatis的mapper.xml文件，我们习惯把它和Mapper.java放一起，都在src/main/java下面，这样利用maven打包时，就需要修改pom.xml文件，来把mapper.xml文件一起打包进jar或者war里了，否则，这些文件不会被打包的。（maven认为src/main/java只是java的源代码路径）。

所以加上该配置可以成功打包进你的jar或war包。当让不知这一种方法。

其他方法配置：

https://www.cnblogs.com/gossip/p/6060840.html