【踩坑】mybatis-spring集成失败

2019-05-28

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [config/spring-context.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1762)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
...
Caused by: java.lang.NullPointerException
    at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:446)
    at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:408)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1821)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1758)
    ... 64 more

mybatis-spring集成过程出现错误，报空指针异常java.lang.NullPointerException，查看AbstractAutowireCapableBeanFactory.java:1762可以发现RootBeanDefinition为null导致，所以推测是RootBeanDefinition注入失败。

因为spring+springMVC正常，所以spring注入功能是正常的，并且项目中使用mybatis的插件mybatis-generator正常，所以mybatis正常，所以最后推测是mybatis-spring的jar包有问题，查看之前的项目，发现之前用的是1.3.2，目前用的是2.0.0，查看相关依赖支持

我用的是本地tomcat，tomcat自带的版本应该不足4.0.1导致我使用2.0.0失败，将mybatis-spring版本用1.3.2成功

    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>1.3.2</version>
    </dependency>

所以啊，使用maven库时不要盲目用新的，用使用较多的比较保险~~~