根据官网全注解无xml整合spring和mybatis遇到的坑

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前言

心血来潮，想根据官网从头搭建一个最简易版全注解spring整合mybatis（仅此而已，无web等），接连几个大坑，记录一下
最后附上成功Demo代码

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一、搭建过程

第一步创建一个maven项目，顺利

第二步引入依赖，不顺利

1.根据官网！只要引入mybatis-spring的jar包即可，我单纯的信了

1-1.（引发的问题）缺依赖

完全复制粘贴，竟然出错！

1-2.（解决办法）这里需要引入另一个jar包提供这个类——如图

2.根据官网！注解版这样配置

2-1.（引发问题）找不到Mapper（我这里叫Dao）接口

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDao' defined in TestMabatis.MyBatisConfig: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [TestMabatis.UserDao]: Factory method 'userDao' threw exception; nested exception is org.apache.ibatis.binding.BindingException: Type interface TestMabatis.UserDao is not known to the MapperRegistry.
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:645)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:475)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1287)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207)
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:874)
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:778)
	... 14 more
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [TestMabatis.UserDao]: Factory method 'userDao' threw exception; nested exception is org.apache.ibatis.binding.BindingException: Type interface TestMabatis.UserDao is not known to the MapperRegistry.
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:640)
	... 28 more
Caused by: org.apache.ibatis.binding.BindingException: Type interface TestMabatis.UserDao is not known to the MapperRegistry.
	at org.apache.ibatis.binding.MapperRegistry.getMapper(MapperRegistry.java:47)
	at org.apache.ibatis.session.Configuration.getMapper(Configuration.java:763)
	at org.mybatis.spring.SqlSessionTemplate.getMapper(SqlSessionTemplate.java:311)
	at TestMabatis.MyBatisConfig.userDao(MyBatisConfig.java:60)
	at TestMabatis.MyBatisConfig$$EnhancerBySpringCGLIB$$9681e4af.CGLIB$userDao$1(<generated>)
	at TestMabatis.MyBatisConfig$$EnhancerBySpringCGLIB$$9681e4af$$FastClassBySpringCGLIB$$6fa77d83.invoke(<generated>)
	at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331)
	at TestMabatis.MyBatisConfig$$EnhancerBySpringCGLIB$$9681e4af.userDao(<generated>)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
	... 29 more

2-2.（解决方法一）去掉这部分，啥问题都没了

2-3.（解决方法二）保留这段代码，前一个Bean添加一句话

3.手贱导入了 6.0.2的mysql-connector-java

3-1.（引发的问题）

The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to

3-2.（解决方案）：

//URL拼接上?serverTimezone=UTC
driverManagerDataSource.setUrl("jdbc:mysql://localhost:3306/testMyBatis?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8");

二、问题分析（待补充）

3.原因：原因是因为使用了Mysql Connector/J 6.x以上的版本，然后就报了时区的错误遇到的问题 servertime=UTC导致时间差8个小时（MySQL jdbc 6.0 版本以上必须配置此参数）

二、代码完整版

1.全部依赖

    <dependencies>
    	
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatis-springartifactId>
            <version>2.0.5version>
        dependency>
        
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>3.5.1version>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-contextartifactId>
            <version>5.2.5.RELEASEversion>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-jdbcartifactId>
            <version>5.2.5.RELEASEversion>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>6.0.2version>
        dependency>
    dependencies>

2.实体类

package TestMabatis;

/**
 * 〈功能简述〉
 
 * 〈〉
 *
 * @author LXN
 * @create 2021/3/31
 * @since 1.0.0
 */
public class User {
     
    private int age;
    private String name;
    private int id;

    public int getAge() {
     
        return age;
    }

    public void setAge(int age) {
     
        this.age = age;
    }

    public String getName() {
     
        return name;
    }

    public void setName(String name) {
     
        this.name = name;
    }

    public int getId() {
     
        return id;
    }

    public void setId(int id) {
     
        this.id = id;
    }
}

3.Dao接口

import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

/**
 * 〈功能简述〉
 
 * 〈接口〉
 *
 * @author LXN
 * @create 2021/3/31
 * @since 1.0.0
 */
public interface UserDao {
     

    @Select("SELECT * FROM sys_user WHERE id = #{id}")
    User getUser(@Param("id") int id);

}

4.Service依照官网写的（我省略了接口）有待研究这种写法

import org.springframework.stereotype.Component;

/**
 * 〈功能简述〉
 
 * 〈〉
 *
 * @author LXN
 * @create 2021/3/31
 * @since 1.0.0
 */
@Component
public class UserServiceImpl{
     
    private final UserDao userDao;

    public UserServiceImpl(UserDao userDao) {
     
        this.userDao = userDao;
    }


    public User getUser(int id) {
     
        User user = userDao.getUser(id);
        return user;
    }
}

5.配置类

package TestMabatis;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

import org.springframework.jdbc.datasource.DriverManagerDataSource;


import javax.sql.DataSource;

/**
 * 〈功能简述〉
 
 * 〈〉
 *
 * @author LXN
 * @create 2021/3/31
 * @since 1.0.0
 */

@ComponentScan("TestMabatis")
@MapperScan(value="TestMabatis")
@Configuration
public class MyBatisConfig {
     

    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
     
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dataSource());
        SqlSessionFactory object = factoryBean.getObject();
        //不加这一句，找不到Dao
        object.getConfiguration().addMapper(UserDao.class);
        return object;
    }
    @Bean
    public UserDao userDao() throws Exception {
     
        SqlSessionTemplate sqlSessionTemplate = new SqlSessionTemplate(sqlSessionFactory());
        return sqlSessionTemplate.getMapper(UserDao.class);
    }

    @Bean
    public DataSource dataSource(){
     
        DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource();
        driverManagerDataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        driverManagerDataSource.setUsername("root");
        driverManagerDataSource.setPassword("root");
        driverManagerDataSource.setUrl("jdbc:mysql://localhost:3306/testMyBatis?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8");
        return driverManagerDataSource;
    }
}

6.测试类

package TestMabatis;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

/**
 * 〈功能简述〉
 
 * 〈〉
 *
 * @author LXN
 * @create 2021/3/31
 * @since 1.0.0
 */
public class TestMybatisMain {
     
    public static void main(String[] args) throws NoSuchFieldException {
     
        AnnotationConfigApplicationContext ac =
                new AnnotationConfigApplicationContext(MyBatisConfig.class);

        UserServiceImpl bean = ac.getBean(UserServiceImpl.class);
        User user = bean.getUser(1);
        System.out.println("获取到"+user.getName());
    }
}

总结

待补充