mybatis-spring项目--再次强行采坑----昨天为什么一直跑步起来,现在了解了!!!

总结
一>applicationContext.xml中:
sqlSessionTemplate可以不配置

<?xml version='1.0' encoding='UTF-8' ?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">
    <!-- 数据库连接池 -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/chapter12" />
        <property name="username" value="root" />
        <property name="password" value="123456" />
        <!--连接池的最大数据库连接数 -->
        <property name="maxActive" value="255" />
        <!--最大等待连接中的数量 -->
        <property name="maxIdle" value="5" />
        <!--最大等待毫秒数 -->
        <property name="maxWait" value="10000" />
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="configLocation" value="mybatis-config.xml" />
    </bean>

    <!--<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">-->
        <!--<constructor-arg ref="sqlSessionFactory"></constructor-arg>-->
    <!--</bean>-->



    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.mapper"></property>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>


        <property name="annotationClass" value="org.springframework.stereotype.Repository"></property>
    </bean>
</beans>

然后注意mapper相关的路径

一>mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <!-- 这个配置使全局的映射器启用或禁用缓存 -->
        <setting name="cacheEnabled" value="true" />
        <!-- 允许 JDBC 支持生成的键。需要适合[修改为：适当]的驱动。如果设置为true，则这个设置强制生成的键被使用，尽管一些驱动拒绝兼容但仍然有效（比如 Derby） -->
        <setting name="useGeneratedKeys" value="true" />
        <!-- 配置默认的执行器。SIMPLE 执行器没有什么特别之处。REUSE 执行器重用预处理语句。BATCH 执行器重用语句和批量更新  -->
        <setting name="defaultExecutorType" value="REUSE" />
        <!-- 全局启用或禁用延迟加载。当禁用时，所有关联对象都会即时加载 -->
        <setting name="lazyLoadingEnabled" value="true"/>
        <!-- 设置超时时间，它决定驱动等待一个数据库响应的时间  -->
        <setting name="defaultStatementTimeout" value="25000"/>
    </settings>
    
    
    <!--别名设置-->
    <typeAliases>
        <typeAlias type="com.pojo.Role" alias="role"></typeAlias>
    </typeAliases>

    <!--指定映射路径-->
    <mappers>
        <mapper resource="mapper/RoleMapper.xml"></mapper>
    </mappers>
</configuration>
```

```xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mapper.RoleMapper">

    <insert id="insertRole" useGeneratedKeys="true" keyProperty="id">
		insert into t_role(role_name, note) values (#{roleName}, #{note})
	</insert>

    <delete id="deleteRole" parameterType="long">
		delete from t_role where id=#{id}
	</delete>

    <select id="getRole" parameterType="long" resultType="role">
		select id, role_name as roleName, note from t_role where id = #{id}
	</select>

    <update id="updateRole" parameterType="role">
		update t_role
		set role_name = #{roleName},
		note = #{roleName}
		where id = #{id}
	</update>
</mapper>
```