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Solve the problem of writing custom mapper in tk. mybatis

  • 2021-09-12 01:28:25
  • OfStack

Problem

Use tk. mybatis can satisfy most operations, but want to add their own query method when encountered a pit today, summary 1

Official tutorials

It can be roughly divided into two types

1. When using pure interface annotation

Add comments such as @ Select and @ insert to the custom method in mapper interface, and write corresponding sql statements inside, as follows 


import org.apache.ibatis.annotations.Select;
import tk.mybatis.mapper.common.Mapper;
public interface CountryMapper extends Mapper<Country> {
    @Select("select * from country where countryname = #{countryname}")
    Country selectByCountryName(String countryname);
}

There is no problem in this way

2. If XML mode is used, XML file corresponding to interface needs to be provided

For example, the CountryMapper. xml file is provided, which reads as follows: 


<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="tk.mybatis.sample.mapper.CountryMapper">
    <select id="selectByCountryName" resultType="tk.mybatis.model.Country">
        select * from country where countryname = #{countryname}
    </select>
</mapper>

There will be some problems here

Note: If resultType is mapped to an entity class, it is best to write the full pathname of the package, such as tk. mybatis. model. Country. If Country is written, an error will be reported, resulting in the project being unable to start.

bug for tk mapper Universal mapper 


<bean class="tk.mybatis.spring.mapper.MapperScannerConfigurer">
            <property name="basePackage" value="com.isea533.mybatis.mapper"/>
            <property name="properties">
                <value>
                    mappers=tk.mybatis.mapper.common.Mapper
                </value>
            </property>
        </bean>

The property value of basePackage cannot contain the package where the generic mapper is located 


Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2018-03-14 12:39:21.741 ERROR [main] [hio-sys] o.s.boot.SpringApplication - Application startup failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'tk.mybatis.mapper.autoconfigure.MapperAutoConfiguration': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'baseMapper' defined in file []: Invocation of init method failed; nested exception is tk.mybatis.mapper.MapperException: tk.mybatis.mapper.MapperException: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:137)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:409)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1620)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
    at org.springframework.context.support.AbstractApplicationContext.__refresh(AbstractApplicationContext.java:543)
    at org.springframework.context.support.AbstractApplicationContext.jrLockAndRefresh(AbstractApplicationContext.java)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
    at com.jzy.hio.HioSysApplication.main(HioSysApplication.java:35)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'baseMapper' defined in file [C:\Users\coffee\OneDrive\workspace\v2r1-hio-base\target\classes\com\jzy\hio\base\mapper\BaseMapper.class]: Invocation of init method failed; nested exception is tk.mybatis.mapper.MapperException: tk.mybatis.mapper.MapperException: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType_jrOrig(DefaultListableBeanFactory.java:519)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType_jrOrig(DefaultListableBeanFactory.java:508)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java)
    at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1188)
    at tk.mybatis.mapper.autoconfigure.MapperAutoConfiguration.addPageInterceptor(MapperAutoConfiguration.java:71)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.__invoke(DelegatingMethodAccessorImpl.java:43)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:366)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:311)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:134)
    ... 18 common frames omitted
Caused by: tk.mybatis.mapper.MapperException: tk.mybatis.mapper.MapperException: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
    at tk.mybatis.mapper.mapperhelper.MapperHelper.setSqlSource(MapperHelper.java:248)
    at tk.mybatis.mapper.mapperhelper.MapperHelper.processConfiguration(MapperHelper.java:311)
    at tk.mybatis.spring.mapper.MapperFactoryBean.checkDaoConfig(MapperFactoryBean.java:54)
    at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624)
    ... 39 common frames omitted
Caused by: tk.mybatis.mapper.MapperException: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
    at tk.mybatis.mapper.mapperhelper.MapperTemplate.setSqlSource(MapperTemplate.java:258)
    at tk.mybatis.mapper.mapperhelper.MapperHelper.setSqlSource(MapperHelper.java:245)
    ... 44 common frames omitted
Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
    at tk.mybatis.mapper.mapperhelper.MapperTemplate.getEntityClass(MapperTemplate.java:290)
    at tk.mybatis.mapper.provider.base.BaseSelectProvider.selectOne(BaseSelectProvider.java:50)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.__invoke(DelegatingMethodAccessorImpl.java:43)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at tk.mybatis.mapper.mapperhelper.MapperTemplate.setSqlSource(MapperTemplate.java:246)
    ... 45 common frames omitted
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