mybatis之动态代理配置

一：Mybatis配置步骤（动态代理实现）：

1）引入maven坐标，及slf4j坐标

           <!--mybatis-->
           <dependency>
               <groupId>org.mybatis</groupId>
               <artifactId>mybatis</artifactId>
<version>3.2.8</version>
           </dependency>
           <!--日志-->
           <dependency>
               <groupId>org.slf4j</groupId>
               <artifactId>slf4j-log4j12</artifactId>
<version>1.6.4</version>
           </dependency>

2）引入jdbc.properties及log4j.properties文件

log4j.properties：

log4j.rootLogger=DEBUG,A1

log4j.logger.com.taotao = DEBUG

log4j.logger.org.mybatis = DEBUG

 

log4j.appender.A1=org.apache.log4j.ConsoleAppender

log4j.appender.A1.layout=org.apache.log4j.PatternLayout

log4j.appender.A1.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss,SSS} [%t] [%c]-[%p] %m%n

jdbc.properties:

jdbc.driverClassName=com.mysql.jdbc.Driver

jdbc.url=jdbc:mysql://127.0.0.1:3306/mybatis_db?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true

jdbc.username=root

jdbc.password=123

3）引入mybatis的全局配置文件(注意：properties/settings/... 标签出现的顺序不能错)

<?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>
    <properties resource="jdbc.properties" />

    <settings>
        <!--设置开启驼峰标识: 命名规则 碰到 user_name 解析成 userName-->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>

    <typeAliases>
    <!--方式一: 给指定类起别名, 适用场景:给比较少的类起别名-->
        <!--<typeAlias type="cn.itcast.pojo.User" alias="User"/>-->
       <!-- 设置别名：为了让sql的xml中的resultType可以直接写下包下面的存在的Class名称-->
        <package name="com.xucj.pojo" />
    </typeAliases>

    <!-- 配置数据库连接的环境 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driverClassName}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
        <!--测试环境
        <environment id="test">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driverClassName}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>-->
    </environments>

    <mappers>
        <mapper resource="mybatis/mapper/UserMapper.xml" />
        <!--方式二:  mapper文件的目录 必须和 mapper接口的package保持一致-->
        <!--<package name="cn.itcast.mapper"/>-->
    </mappers>
</configuration>

4）创建mapper接口userMapper

public interface UserMapper {

    public User findUserById(Long id);

    public List<User> findUserAll();

    public int deleteUserById(String id);

    public int updateUser(User user);

    public int addUser(User user);
}

5）创建userMapper.xml文件（注意：namespace的值等于mapper接口的地址，select的id必须和mapper接口的方法相同。）

<?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.xucj.mapper.user.UserMapper">

    <select id="findUserById" parameterType="long" resultType="User">
        select * from tb_user
        where 1=1 and id = #{id}
    </select>

</mapper>

6）userMapper.xml和userMapper接口的目录结合mybatis全局配置文件截图说明：

7）测试：