解決tk.mybatis中寫自定義的mapper的問題

更新時間：2021年06月11日 11:09:51 作者：偉大的格爾夫斯

這篇文章主要介紹了使用tk.mybatis中寫自定義的mapper的問題，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教

問題

使用tk.mybatis能滿足大多數(shù)操作，但是想添加自己的查詢方法時候今天遇到了坑，總結(jié)一下

大致分兩種

1. 使用純接口注解方式時

在mapper接口中自定義方法上添加如@Select，@insert類似的注釋，里邊寫相應(yīng)的sql語句，如下

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);
}

這種方式?jīng)]有問題

2. 如果使用 XML 方式，需要提供接口對應(yīng)的 XML 文件

例如提供了 CountryMapper.xml 文件，內(nèi)容如下：

<!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>

這里會有點(diǎn)問題

注意： resultType 如果映射的是個實(shí)體類最好寫包的全路徑名如tk.mybatis.model.Country 如果寫 Country會報錯，導(dǎo)致項目無法啟動。

tk mapper 通用mapper的bug

<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>

basePackage的屬性值不能包含通用mapper所在的包

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

以上為個人經(jīng)驗，希望能給大家一個參考，也希望大家多多支持腳本之家。

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