org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 6; 不允許有匹配 "[xX][mM][lL]" 的處理指令目標。

Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException:
### Error building SqlSession.
### The error may exist in com/qianfeng/bean/PetsMapper.xml
### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 6; 不允許有匹配 "[xX][mM][lL]" 的處理指令目標。
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:52)
at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:36)
at com.qianfeng.test.Test.main(Test.java:17)

上面是報的錯，到了petsMapper.xml頁面后看到了錯誤的地方所在，原來是多寫了一個頭部，刪除掉就可以了

<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">