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MyBatis01 学习遇到的错误

MyBatis01 学习遇到的错误

错误1

java.lang.NullPointerException
 at com.utils.MybatisUtils.getSqlSession(MybatisUtils.java:34)
 at com.dao.UserDaoTest.test(UserDaoTest.java:14)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at s

 这里一直空指针异常,原因是重复定义了sqlSessionFactory对象,把下面的SqlSessionFactory删去即可,修改后:

 错误2

配置文件中路径一定是斜杠“/”!!!不是点!

 错误3

在些delUser()方法时parameterType写错

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.dao.UserMapper.delUser

 at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:235)
 at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:53)
 at org.apache.ibatis.binding.MapperProxy.lambda$cachedMapperMethod$0(MapperProxy.java:98)

 

 修改后:

 错误4

解决org.apache.ibatis.binding.BindingException: Invalid bound statement (not found)问题

这是因为生成的target文件中找不到配置文件UserMapper.xml

 解决方法,在父项目和子项目的pom.xml的<properties>标签内都加上:

 <build><resources><resource><directory>src/main/java</directory><includes><include>/*.xml</include><include>/*.properties</include></includes><filtering>true</filtering></resource><resource><directory>src/main/resources</directory><includes><include>/*.xml</include><include>/*.properties</include></includes><filtering>true</filtering></resource></resources></build>

添加完后一定记得刷新!!maven需要刷新才能生效!!!