Mybatis(五)：Mybatis的三种使用方式
注意，这篇文章只介绍 mybatis 单独使用时如何操作，是没有用到 spring 的，如果需要了解 mybatis 和 spring 如何搭建，请移步这里Mybatis(六)：spring 与 mybatis 三种整合方法。
方式一：不使用 mapper 接口
步骤
1.pom 文件里添加 jar 包
<dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.3.0</version> </dependency>
2. 准备 Mybatis 的配置文件
<?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><span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">settings</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)"> 打印查询语句 </span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">setting </span><span style="color: rgba(255, 0, 0, 1)">name</span><span style="color: rgba(0, 0, 255, 1)">="logImpl"</span><span style="color: rgba(255, 0, 0, 1)"> value</span><span style="color: rgba(0, 0, 255, 1)">="STDOUT_LOGGING"</span> <span style="color: rgba(0, 0, 255, 1)">/></span> <span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">settings</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)"> 和Spring整合后environment配置都会被干掉 </span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">environments </span><span style="color: rgba(255, 0, 0, 1)">default</span><span style="color: rgba(0, 0, 255, 1)">="development"</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">environment </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="development"</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)"> 使用jdbc事务管理，目前由mybatis来管理 </span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">transactionManager </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="JDBC"</span> <span style="color: rgba(0, 0, 255, 1)">/></span> <span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)"> 数据库连接池，目前由mybatis来管理 </span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">dataSource </span><span style="color: rgba(255, 0, 0, 1)">type</span><span style="color: rgba(0, 0, 255, 1)">="POOLED"</span><span style="color: rgba(0, 0, 255, 1)">></span><span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)">有关于mysql数据库的各种信息</span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">property </span><span style="color: rgba(255, 0, 0, 1)">name</span><span style="color: rgba(0, 0, 255, 1)">="driver"</span><span style="color: rgba(255, 0, 0, 1)"> value</span><span style="color: rgba(0, 0, 255, 1)">="com.mysql.jdbc.Driver"</span> <span style="color: rgba(0, 0, 255, 1)">/></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">property </span><span style="color: rgba(255, 0, 0, 1)">name</span><span style="color: rgba(0, 0, 255, 1)">="url"</span><span style="color: rgba(255, 0, 0, 1)"> value</span><span style="color: rgba(0, 0, 255, 1)">="jdbc:mysql://localhost:3306/mybatis"</span> <span style="color: rgba(0, 0, 255, 1)">/></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">property </span><span style="color: rgba(255, 0, 0, 1)">name</span><span style="color: rgba(0, 0, 255, 1)">="username"</span><span style="color: rgba(255, 0, 0, 1)"> value</span><span style="color: rgba(0, 0, 255, 1)">="root"</span> <span style="color: rgba(0, 0, 255, 1)">/></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">property </span><span style="color: rgba(255, 0, 0, 1)">name</span><span style="color: rgba(0, 0, 255, 1)">="password"</span><span style="color: rgba(255, 0, 0, 1)"> value</span><span style="color: rgba(0, 0, 255, 1)">="123456"</span> <span style="color: rgba(0, 0, 255, 1)">/></span> <span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">dataSource</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">environment</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">environments</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">mappers</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)">将操作配置文件User.xml系添加进mapper</span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">mapper </span><span style="color: rgba(255, 0, 0, 1)">resource</span><span style="color: rgba(0, 0, 255, 1)">="mybatis/user.xml"</span> <span style="color: rgba(0, 0, 255, 1)">/></span> <span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">mappers</span><span style="color: rgba(0, 0, 255, 1)">></span></configuration>
更多的参数配置，参阅：Mybatis(一)：MyBatis 配置文件 config.xml 详解
3. 准备实体类
public class User {</span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String id; </span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String password; </span><span style="color: rgba(0, 0, 255, 1)">private</span><span style="color: rgba(0, 0, 0, 1)"> String username; </span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getId() { </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> id; } </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setId(String id) { </span><span style="color: rgba(0, 0, 255, 1)">this</span>.id =<span style="color: rgba(0, 0, 0, 1)"> id; } </span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getPassword(){ </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> password; } </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setPassword(String password){ </span><span style="color: rgba(0, 0, 255, 1)">this</span>.password=<span style="color: rgba(0, 0, 0, 1)">password; } </span><span style="color: rgba(0, 0, 255, 1)">public</span><span style="color: rgba(0, 0, 0, 1)"> String getUsername(){ </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> username; } </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> setUsername(String username){ </span><span style="color: rgba(0, 0, 255, 1)">this</span>.username=<span style="color: rgba(0, 0, 0, 1)">username; }}
4. 准备实体对应的 mapper 映射 xml 文件
<?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="user"> <!-- 注意，因为这边没有用到 mapper 接口，所以这里的 namespace 不需要是完全的类名 -->
<span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)"> 通过id查询用户 </span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">select </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="findUserById"</span><span style="color: rgba(255, 0, 0, 1)"> parameterType</span><span style="color: rgba(0, 0, 255, 1)">="int"</span><span style="color: rgba(255, 0, 0, 1)"> resultType</span><span style="color: rgba(0, 0, 255, 1)">="com.mvc.User"</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">include </span><span style="color: rgba(255, 0, 0, 1)">refid</span><span style="color: rgba(0, 0, 255, 1)">="selectStr"</span><span style="color: rgba(0, 0, 255, 1)">/></span><span style="color: rgba(0, 0, 0, 1)"> id = #{id} </span><span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">select</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)">通过name查找一个list的用户，模糊匹配</span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">select </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="findUserByName"</span><span style="color: rgba(255, 0, 0, 1)"> parameterType</span><span style="color: rgba(0, 0, 255, 1)">="java.lang.String"</span><span style="color: rgba(255, 0, 0, 1)"> resultType</span><span style="color: rgba(0, 0, 255, 1)">="com.mvc.User"</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 128, 0, 1)">select * from user where name like '%${value}%'</span> <span style="color: rgba(0, 0, 255, 1)"></</span><span style="color: rgba(128, 0, 0, 1)">select</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 128, 0, 1)"><!--</span><span style="color: rgba(0, 128, 0, 1)">插入用户信息</span><span style="color: rgba(0, 128, 0, 1)">--></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">insert </span><span style="color: rgba(255, 0, 0, 1)">id</span><span style="color: rgba(0, 0, 255, 1)">="insertUser"</span><span style="color: rgba(255, 0, 0, 1)"> parameterType</span><span style="color: rgba(0, 0, 255, 1)">="com.mvc.User"</span><span style="color: rgba(0, 0, 255, 1)">></span> <span style="color: rgba(0, 0, 255, 1)"><</span><span style="color: rgba(128, 0, 0, 1)">selectKey </span><span style="color: rgba(255, 0, 0, 1)">keyProperty</span><span style="color: rgba(0, 0, 255, 1)">="id"</span><span style="color: rgba(255, 0, 0, 1)"> order</span><span style="color: rgba(0, 0, 255, 1)">="BEFORE"</span><span style="color: rgba(255, 0, 0, 1)"> resultType</span><span style="color: rgba(0, 0, 255, 1)">="java.lang.String"</span><span style="color: rgba(0, 0, 255, 1)">></span><span style="color: rgba(0, 0, 0, 1)"> select uuid()<!-- 这里是对于主键属性的 id 进行赋值 -->
</selectKey>
insert into user(id,username,password) values(#{id},#{username},#{password})
</insert>
<!--删除用户信息-->
<delete id="deleteUser" parameterType="java.lang.Integer">
delete from user where id=#{id}
</delete>
<!--更新用户信息-->
<update id="updateUser" parameterType="com.mvc.User">
<!-- update user set name=#{name},password=#{password} where id=#{id} -->
update user
<set>
<if test="username != null && username !=''">username=#{username},</if>
<if test="password != null && password !=''">password=#{password},</if>
</set>
where id= #{id}
</update>
</mapper>
5. 准备一个获取 sqlsession 的工具类
import java.io.IOException; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class MybatisSessionUtil {
</span><span style="color: rgba(0, 0, 255, 1)">static</span> SqlSessionFactory sqlSessionFactory = <span style="color: rgba(0, 0, 255, 1)">null</span><span style="color: rgba(0, 0, 0, 1)">; </span><span style="color: rgba(0, 0, 255, 1)">static</span><span style="color: rgba(0, 0, 0, 1)">{ SqlSessionFactoryBuilder sqlSessionFactoryBuilder </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> SqlSessionFactoryBuilder(); </span><span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)"> { sqlSessionFactory </span>= sqlSessionFactoryBuilder.build(Resources.getResourceAsStream("mybatis-config.xml"<span style="color: rgba(0, 0, 0, 1)">)); } </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (IOException e) { e.printStackTrace(); } } </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span><span style="color: rgba(0, 0, 0, 1)"> SqlSession getSession(){ </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> sqlSessionFactory.openSession(); }}
6. 准备 dao
import org.apache.ibatis.session.SqlSession;import com.mvc.User;
import com.mybatis.mapper.User2Mapper;public class UserDao {
SqlSession session </span>=<span style="color: rgba(0, 0, 0, 1)"> MybatisSessionUtil.getSession(); </span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> insert(User user){ </span><span style="color: rgba(0, 0, 255, 1)">int</span> rint = session.insert("user.insertUser"<span style="color: rgba(0, 0, 0, 1)">,user); <span style="color: rgba(255, 0, 0, 1)">//</span> <span style="color: rgba(255, 0, 0, 1)">第一个参数是mapper xml里的namespace+MappedStatement对应的id</span> session.commit();<span style="color: rgba(255, 0, 0, 1)">// 不要忘记提交 </span></span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> rint; }</span><span style="color: rgba(0, 0, 0, 1)">}
7. 看下数据里 user 表
8. 测试类
import com.mvc.User; import com.mybatis.util.UserDao;public class MybatisNoSpringTest {
}</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> main(String[] args) { UserDao userDao </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> UserDao(); User user </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> User(); user.setUsername(</span>"wwwttt"<span style="color: rgba(0, 0, 0, 1)">); user.setPassword(</span>"33333"<span style="color: rgba(0, 0, 0, 1)">); </span><span style="color: rgba(0, 0, 255, 1)">if</span> (userDao.insert(user) == 1<span style="color: rgba(0, 0, 0, 1)">) { System.out.println(</span>"insert success..."<span style="color: rgba(0, 0, 0, 1)">); }</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)">{ System.out.println(</span>"insert fail..."<span style="color: rgba(0, 0, 0, 1)">); }}
方式二：使用 mapper 接口
步骤
1.pom 文件里添加 jar 包
同方式一
2. 准备 Mybatis 的配置文件
同方式一，就是换成新的 user mapper xml
<mappers> <!--将操作配置文件系添加进 mapper--> <mapper resource="mybatis/User2Mapper.xml" /> </mappers>
3. 准备实体类
同方式一
4. 准备 mapper 接口（这个是比方式一多出来的）
import com.mvc.User;// 这边接口名要和 xml 映射的文件名一致
public interface User2Mapper {</span><span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> insertUser(User user); </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 其它方法略。。。 </span>}
5. 准备实体对应的 mapper 映射 xml 文件
同方式一, 只是namespace 需要注意
<?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"><!-- 这边的 namespace 一定要写完整正确 -->
<mapper namespace="com.mybatis.mapper.User2Mapper">
<!-- 通过 id 查询用户 -->
<select id="findUserById" parameterType="int" resultType="com.mvc.User">
select * from user where id = #{id}
</select>
<!--通过 name 查找一个 list 的用户，模糊匹配-->
<select id="findUserByName" parameterType="java.lang.String" resultType="com.mvc.User">
select * from user where name like '%${value}%'
</select>
<!--插入用户信息-->
<insert id="insertUser" parameterType="com.mvc.User">
<selectKey keyProperty="id" order="BEFORE" resultType="java.lang.String">
select uuid()
<!-- 这里是对于主键属性的 id 进行赋值 -->
</selectKey>
insert into user(id,username,password) values(#{id},#{username},#{password})
</insert>
<!--删除用户信息-->
<delete id="deleteUser" parameterType="java.lang.Integer">
delete from user where id=#{id}
</delete>
<!--更新用户信息-->
<update id="updateUser" parameterType="com.mvc.User">
update user set name=#{name},password=#{password} where id=#{id}
</update></mapper>
6. 准备一个获取 sqlsession 的工具类
同方式一
7. 准备 dao
import org.apache.ibatis.session.SqlSession;import com.mvc.User;
import com.mybatis.mapper.User2Mapper;public class UserDao {
SqlSession session </span>=<span style="color: rgba(0, 0, 0, 1)"> MybatisSessionUtil.getSession(); </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 使用接口方式</span> <span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">int</span><span style="color: rgba(0, 0, 0, 1)"> insert2(User user){ User2Mapper user2Mapper </span>= session.getMapper(User2Mapper.<span style="color: rgba(0, 0, 255, 1)">class</span><span style="color: rgba(0, 0, 0, 1)">); </span><span style="color: rgba(0, 0, 255, 1)">int</span> rint =<span style="color: rgba(0, 0, 0, 1)"> user2Mapper.insertUser(user); session.commit(); </span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> rint; }}
8. 测试类
import com.mvc.User; import com.mybatis.util.UserDao;public class MybatisNoSpringTest {
</span><span style="color: rgba(0, 0, 255, 1)">public</span> <span style="color: rgba(0, 0, 255, 1)">static</span> <span style="color: rgba(0, 0, 255, 1)">void</span><span style="color: rgba(0, 0, 0, 1)"> main(String[] args) { UserDao userDao </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> UserDao(); User user </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> User(); user.setUsername(</span>"wwwttt"<span style="color: rgba(0, 0, 0, 1)">); user.setPassword(</span>"33333"<span style="color: rgba(0, 0, 0, 1)">); </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)"> 使用mapper接口方式</span> <span style="color: rgba(0, 0, 255, 1)">if</span> (userDao.insert2(user) == 1<span style="color: rgba(0, 0, 0, 1)">) { System.out.println(</span>"insert success..."<span style="color: rgba(0, 0, 0, 1)">); }</span><span style="color: rgba(0, 0, 255, 1)">else</span><span style="color: rgba(0, 0, 0, 1)">{ System.out.println(</span>"insert fail..."<span style="color: rgba(0, 0, 0, 1)">); } }}
方式三：使用 mybatis 框架的注解编写 sql
这种方式，我不推荐使用，本来我们使用 mybatis 就是为了 sql 编写和 java 代码能分开解耦，有更大的灵活性，使用这种方式反而不好。
另外，myatis 官方也不推荐这种方式，官方说了，要想使用 mybatis 强大的 sql 编写功能，写在注解里是受到限制的，只有写在 mapper xml 里才能发挥的玲离尽致。
所以，这种方法我就不记录了，有需要的同学自行百度。