Mybatis入门案列

Mybatis使用案例

JDBC的缺点

1. 数据库链接创建、释放频繁造成系统资源浪费从而影响系统性能，如果使用数据库链接池可解决此问题。
2. Sql语句在代码中硬编码，造成代码不易维护，实际应用sql变化的可能较大，sql变动需要改变java代码。
3. 使用preparedStatement向占有位符号传参数存在硬编码，因为sql语句的where条件不一定，可能多也可能少，修改sql还要修改代码，系统不易维护。
4. 对结果集解析存在硬编码（查询列名），sql变化导致解析代码变化，系统不易维护，如果能将数据库记录封装成pojo对象解析比较方便。

Mybatis入门案例

1. 数据库配置文件(db.properties)

   jdbc.driver=com.mysql.jdbc.Driver
   jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8
   jdbc.username=root
   jdbc.password=admin

2. 全局配置文件SqlMapConfig.xml,只有一个

   <?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="db.properties"></properties>
   <!--mybatis自带别名：
       别名  映射的类型
          _byte    byte 
          _long    long 
          _short   short 
          _int     int 
          _integer     int 
          _double  double 
          _float   float 
          _boolean     boolean 
          string   String 
          byte     Byte 
          long     Long 
          short    Short 
          int  Integer 
          integer  Integer 
          double   Double 
          float    Float 
          boolean  Boolean 
          date     Date 
          decimal  BigDecimal 
          bigdecimal   BigDecimal 
          map  Map
   -->
   <typeAliases> 
       <!-- 定义单个pojo类别名
       type:类的全路径名称
       alias:别名
        -->
   <!--         <typeAlias type="cn.xx.pojo.User" alias="user"/> -->
   
       <!-- 使用包扫描的方式批量定义别名 
       定以后别名等于类名,不区分大小写,但是建议按照java命名规则来,首字母小写,以后每个单词的首字母大写
       -->
       <package name="cn.xx.pojo"/>
   </typeAliases>
   
   <!-- 和spring整合后 environments配置将废除-->
   <environments default="development">
       <environment id="development">
       <!-- 使用jdbc事务管理-->
       <transactionManager type="JDBC" />
       <!-- 数据库连接池-->
       <dataSource type="POOLED">
           <property name="driver" value="${jdbc.driver}" />
           <property name="url" value="${jdbc.url}" />
           <property name="username" value="${jdbc.username}" />
           <property name="password" value="${jdbc.password}" />
       </dataSource>
       </environment>
   </environments>
   
   <mappers>
       <mapper resource="User.xml"/>
   
       <!-- 
       使用class属性引入接口的全路径名称:
       使用规则:
           1. 接口的名称和映射文件名称除扩展名外要完全相同
           2. 接口和映射文件要放在同一个目录下
        -->
   <!--         <mapper class="cn.xx.mapper.UserMapper"/> -->
   
       <!-- 使用包扫描的方式批量引入Mapper接口 
               使用规则:
               1. 接口的名称和映射文件名称除扩展名外要完全相同
               2. 接口和映射文件要放在同一个目录下
       -->
       <package name="cn.xx.mapper"/>
   </mappers>
   </configuration>

3. 配置mapper(User.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">
   <!-- namespace:命名空间,做sql隔离 -->
   <mapper namespace="test">
   
   <!-- 
   id:sql语句唯一标识
   parameterType:指定传入参数类型
   resultType:返回结果集类型
   
   #{}占位符:起到占位作用,如果传入的是基本类型(string,long,double,int,boolean,float等),那么#{}中的变量名称可以随意写.
   
    -->
   <select id="findUserById" parameterType="java.lang.Integer" resultType="cn.xx.pojo.User">
       select * from user where id=#{id}
   </select>
   
   <!-- 
   如果返回结果为集合,可以调用selectList方法,这个方法返回的结果就是一个集合,所以映射文件中应该配置成集合泛型的类型
   ${}拼接符:字符串原样拼接,如果传入的参数是基本类型(string,long,double,int,boolean,float等),那么${}中的变量名称必须是value
   注意:拼接符有sql注入的风险,所以慎重使用
    -->
   <select id="findUserByUserName" parameterType="java.lang.String" resultType="cn.xx.pojo.User">
       select * from user where username like '%${value}%'
   </select>
   
   <!-- 
   
   #{}:如果传入的是pojo类型,那么#{}中的变量名称必须是pojo中对应的属性.属性.属性.....
   
   如果要返回数据库自增主键:可以使用select LAST_INSERT_ID()
    -->
   <insert id="insertUser" parameterType="cn.xx.pojo.User" >
       <!-- 执行 select LAST_INSERT_ID()数据库函数,返回自增的主键
       keyProperty:将返回的主键放入传入参数的Id中保存.
       order:当前函数相对于insert语句的执行顺序,在insert前执行是before,在insert后执行是AFTER
       resultType:id的类型,也就是keyproperties中属性的类型
       -->
       <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
           select LAST_INSERT_ID()
       </selectKey>
       insert into user (username,birthday,sex,address) values(#{username},#{birthday},#{sex},#{address})
   </insert>
   
   <delete id="delUserById" parameterType="int">
       delete from user where id=#{id}
   </delete>
   
   <update id="updateUserById" parameterType="cn.xx.pojo.User">
       update user set username=#{username} where id=#{id}
   </update>
   </mapper>

4. test类

   package mybatis0523;
   
   import java.io.InputStream;
   import java.util.Date;
   import java.util.List;
   
   import org.apache.ibatis.io.Resources;
   import org.apache.ibatis.session.SqlSession;
   import org.apache.ibatis.session.SqlSessionFactory;
   import org.apache.ibatis.session.SqlSessionFactoryBuilder;
   import org.junit.Test;
   
   import cn.xx.pojo.User;
   
   public class UserTest {
   
   @Test
   public void testFindUserById() throws Exception{
       String resource = "SqlMapConfig.xml";
       //通过流将核心配置文件读取进来
       InputStream inputStream = Resources.getResourceAsStream(resource);
       //通过核心配置文件输入流来创建会话工厂
       SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
       //通过工厂创建会话
       SqlSession openSession = factory.openSession();
       //第一个参数:所调用的sql语句= namespace+.+sql的ID
       User user = openSession.selectOne("test.findUserById", 1);
       System.out.println(user);
       openSession.close();
   }
   
   @Test
   public void testFindUserbyUserName() throws Exception{
       String resource = "SqlMapConfig.xml";
       InputStream inputStream = Resources.getResourceAsStream(resource);
       SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
       SqlSession openSession = factory.openSession();
   
       List<User> list = openSession.selectList("test.findUserByUserName", "王");
       System.out.println(list);
   }
   
   @Test
   public void testInsertUser() throws Exception{
       String resource = "SqlMapConfig.xml";
       //通过流将核心配置文件读取进来
       InputStream inputStream = Resources.getResourceAsStream(resource);
       //通过核心配置文件输入流来创建会话工厂
       SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
       //通过工厂创建会话
       SqlSession openSession = factory.openSession();
   
       User user = new User();
       user.setUsername("赵四");
       user.setBirthday(new Date());
       user.setSex("1");
       user.setAddress("北京昌平");
       System.out.println("====" + user.getId());
   
       openSession.insert("test.insertUser", user);
       //提交事务(mybatis会自动开启事务,但是它不知道何时提交,所以需要手动提交事务)
       openSession.commit();
   
       System.out.println("====" + user.getId());
   }
   
   @Test
   public void testDelUserById()throws Exception{
       String resource = "SqlMapConfig.xml";
       //通过流将核心配置文件读取进来
       InputStream inputStream = Resources.getResourceAsStream(resource);
       //通过核心配置文件输入流来创建会话工厂
       SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
       //通过工厂创建会话
       SqlSession openSession = factory.openSession();
   
       openSession.delete("test.delUserById", 29);
       //提交
       openSession.commit();
   }
   
   @Test
   public void testUpdateUserById() throws Exception{
       String resource = "SqlMapConfig.xml";
       //通过流将核心配置文件读取进来
       InputStream inputStream = Resources.getResourceAsStream(resource);
       //通过核心配置文件输入流来创建会话工厂
       SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(inputStream);
       //通过工厂创建会话
       SqlSession openSession = factory.openSession();
   
       User user = new User();
       user.setId(28);
       user.setUsername("王麻子");
       openSession.update("test.updateUserById", user);
   
       //提交
       openSession.commit();
   }
   }

5. 生成自增主键并返回的配置

   <insert id="insertUser" parameterType="cn.itcast.mybatis.po.User">
    <!-- selectKey将主键返回，需要再返回 -->
    <selectKey keyProperty="id" order="BEFORE" resultType="java.lang.String">
    select uuid()
    </selectKey>
    insert into user(username,birthday,sex,address)
    values(#{username},#{birthday},#{sex},#{address});
   </insert>
   

   添加selectKey实现将主键返回

   keyProperty:返回的主键存储在pojo中的哪个属性

   order：selectKey的执行顺序，是相对与insert语句来说，由于mysql的自增原理执行完insert语句之后才将主键生成，所以这里selectKey的执行顺序为after

   resultType:返回的主键是什么类型

简单的Dao层写法

1. 原生DAO的实现类（xml还是上面那个）

   public class UserDaoImpl implements UserDao {
   
   private SqlSess ionFactory sqlSessionFactory;
   
   //通过构造方法注入
   public UserDaoImpl(SqlSessionFactory sqlSessionFactory) {
       this.sqlSessionFactory = sqlSessionFactory;
   }
   
   @Override
   public User findUserById(Integer id) {
       //sqlSesion是线程不安全的,所以它的最佳使用范围在方法体内
       SqlSession openSession = sqlSessionFactory.openSession();
       User user = openSession.selectOne("test.findUserById", id);
       return user;
   }
   
   @Override
   public List<User> findUserByUserName(String userName) {
       SqlSession openSession = sqlSessionFactory.openSession();
       List<User> list = openSession.selectList("test.findUserByUserName", userName);
       return list;
   }
   
   
   }

   Test类：

   public class UserDaoTest {
   
   private SqlSessionFactory factory;
   
   //作用:在测试方法前执行这个方法
   @Before
   public void setUp() throws Exception{
       String resource = "SqlMapConfig.xml";
       //通过流将核心配置文件读取进来
       InputStream inputStream = Resources.getResourceAsStream(resource);
       //通过核心配置文件输入流来创建会话工厂
       factory = new SqlSessionFactoryBuilder().build(inputStream);
   }
   
   @Test
   public void testFindUserById() throws Exception{
       //将初始化好的工厂注入到实现类中
       UserDao userDao = new UserDaoImpl(factory);
   
       User user = userDao.findUserById(1);
       System.out.println(user);
   }
   
   @Test
   public void testFindUserByUserName () throws Exception{
   
       UserDao userDao = new UserDaoImpl(factory);
   
       List<User> list = userDao.findUserByUserName("王");
       System.out.println(list);
   }
   }

   ​

2. 动态代理方式

   UserMapper.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接口代理实现编写规则:
   1. 映射文件中namespace要等于接口的全路径名称
   2. 映射文件中sql语句id要等于接口的方法名称
   3. 映射文件中传入参数类型要等于接口方法的传入参数类型
   4. 映射文件中返回结果集类型要等于接口方法的返回值类型
   -->
   <mapper namespace="cn.xx.mapper.UserMapper">
   <select id="findUserById" parameterType="int" resultType="cn.xx.pojo.User">
       select * from user where id=#{id}
   </select>
   <select id="findUserByUserName" parameterType="string" resultType="user">
       select * from user where username like '%${value}%'
   </select>
   <insert id="insertUser" parameterType="cn.xx.pojo.User" >
       <!-- 执行 select LAST_INSERT_ID()数据库函数,返回自增的主键
       keyProperty:将返回的主键放入传入参数的Id中保存.
       order:当前函数相对于insert语句的执行顺序,在insert前执行是before,在insert后执行是AFTER
       resultType:id的类型,也就是keyproperties中属性的类型
       -->
       <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
           select LAST_INSERT_ID()
       </selectKey>
       insert into user (username,birthday,sex,address) values(#{username},#{birthday},#{sex},#{address})
   </insert>
   </mapper>

   接口：

   package cn.xx.mapper;
   import java.util.List;
   import cn.xx.pojo.User;
   public interface UserMapper {
   
   public User findUserById(Integer id);
   //动态代理形势中,如果返回结果集问List,那么mybatis会在生成实现类的使用会自动调用selectList方法
   public List<User> findUserByUserName(String userName);
   public void insertUser(User user);
   }
   

   test类：

   public class UserMapperTest {
   private SqlSessionFactory factory;
   
   //作用:在测试方法前执行这个方法
   @Before
   public void setUp() throws Exception{
       String resource = "SqlMapConfig.xml";
       //通过流将核心配置文件读取进来
       InputStream inputStream = Resources.getResourceAsStream(resource);
       //通过核心配置文件输入流来创建会话工厂
       factory = new SqlSessionFactoryBuilder().build(inputStream);
   }
   
   @Test
   public void testFindUserById() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       User user = mapper.findUserById(1);
       System.out.println(user);
   }
   
   @Test
   public void testFindUserByUserName() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       List<User> list = mapper.findUserByUserName("王");
   
       System.out.println(list);
   }
   
   @Test
   public void testInsertUser() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       User user = new User();
       user.setUsername("老王");
       user.setSex("1");
       user.setBirthday(new Date());
       user.setAddress("北京昌平");
   
       mapper.insertUser(user);
   
       openSession.commit();
   }
   }

传递复杂类型(输入映射，输出映射)

1. UserMapper.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="cn.xx.mapper.UserMapper">
   <!-- 封装sql条件,封装后可以重用. 
   id:是这个sql条件的唯一标识 -->
   <sql id="user_Where">
       <!-- where标签作用:
               会自动向sql语句中添加where关键字
               会去掉第一个条件的and关键字
            -->
       <where>
           <if test="username != null and username != ''">
               and username like '%${username}%'
           </if>
           <if test="sex != null and sex != ''">
               and sex=#{sex}
           </if>
       </where>
   </sql>
   
   <select id="findUserbyVo" parameterType="cn.xx.pojo.QueryVo" resultType="cn.xx.pojo.User">
       select * from user where username like '%${user.username}%' and sex=#{user.sex}
   </select>
   
   <!-- 只有返回结果为一行一列的时候,那么返回值类型才可以指定成基本类型 -->
   <select id="findUserCount" resultType="java.lang.Integer">
       select count(*) from user 
   </select>
   
   <select id="findUserByUserNameAndSex" parameterType="cn.xx.pojo.User" resultType="cn.xx.pojo.User">
       select * from user 
   
       <!-- 调用sql条件 -->
       <include refid="user_Where"></include>
   </select>
   
   <select id="findUserByIds" parameterType="cn.xx.pojo.QueryVo" resultType="cn.xx.pojo.User">
       select * from user
   
       select * from user
       <where>
           <if test="ids != null">
               <!-- 
               foreach:循环传入的集合参数
               collection:传入的集合的变量名称
               item:每次循环将循环出的数据放入这个变量中
               open:循环开始拼接的字符串
               close:循环结束拼接的字符串
               separator:循环中拼接的分隔符
                -->
               <foreach collection="ids" item="id" open="id in (" close=")" separator=",">
                   #{id}
               </foreach>
           </if>
       </where>
   </select>
   
   
   <!-- 一对一:自动映射 -->
   <select id="findOrdersAndUser1" resultType="cn.xx.pojo.CustomOrders">
       select a.*, b.id uid, username, birthday, sex, address 
       from orders a, user b 
       where a.user_id = b.id
   </select>
   
   <!-- 一对一:手动映射 -->
   <!-- 
   id:resultMap的唯一标识
   type:将查询出的数据放入这个指定的对象中
   注意:手动映射需要指定数据库中表的字段名与java中pojo类的属性名称的对应关系
    -->
   <resultMap type="cn.xx.pojo.Orders" id="orderAndUserResultMap">
       <!-- id标签指定主键字段对应关系
       column:列,数据库中的字段名称
       property:属性,java中pojo中的属性名称
        -->
       <id column="id" property="id"/>
   
       <!-- result:标签指定非主键字段的对应关系 -->
       <result column="user_id" property="userId"/>
       <result column="number" property="number"/>
       <result column="createtime" property="createtime"/>
       <result column="note" property="note"/>
   
       <!-- 这个标签指定单个对象的对应关系 
       property:指定将数据放入Orders中的user属性中
       javaType:user属性的类型
       -->
       <association property="user" javaType="cn.xx.pojo.User">
           <id column="uid" property="id"/>
           <result column="username" property="username"/>
           <result column="birthday" property="birthday"/>
           <result column="sex" property="sex"/>
           <result column="address" property="address"/>
       </association>
   </resultMap>
   <select id="findOrdersAndUser2" resultMap="orderAndUserResultMap">
       select a.*, b.id uid, username, birthday, sex, address 
       from orders a, user b 
       where a.user_id = b.id
   </select>
   
   <resultMap type="cn.xx.pojo.User" id="userAndOrdersResultMap">
       <id column="id" property="id"/>
       <result column="username" property="username"/>
       <result column="birthday" property="birthday"/>
       <result column="sex" property="sex"/>
       <result column="address" property="address"/>
   
       <!-- 指定对应的集合对象关系映射
       property:将数据放入User对象中的ordersList属性中
       ofType:指定ordersList属性的泛型类型
        -->
       <collection property="ordersList" ofType="cn.xx.pojo.Orders">
           <id column="oid" property="id"/>
           <result column="user_id" property="userId"/>
           <result column="number" property="number"/>
           <result column="createtime" property="createtime"/>
       </collection>
   </resultMap>
   <select id="findUserAndOrders" resultMap="userAndOrdersResultMap">
       select a.*, b.id oid ,user_id, number, createtime 
       from user a, orders b where a.id = b.user_id
   </select>
   </mapper>

2. UserMapper,对应的接口类

   public interface UserMapper {
   
   public User findUserById(Integer id);
   //动态代理形势中,如果返回结果集问List,那么mybatis会在生成实现类的使用会自动调用selectList方法
   public List<User> findUserByUserName(String userName);
   public void insertUser(User user);
   public List<User> findUserbyVo(QueryVo vo);
   public Integer findUserCount();
   public List<User> findUserByUserNameAndSex(User user);
   public List<User> findUserByIds(QueryVo vo);
   public List<CustomOrders> findOrdersAndUser1() ;
   public List<Orders> findOrdersAndUser2();
   public List<User> findUserAndOrders();
   }

3. 实体类

   public class User {
   private int id;
   private String username;// 用户姓名
   private String sex;// 性别
   private Date birthday;// 生日
   private String address;// 地址
   ...
   }

   public class QueryVo {
   private User user;  
   private List<Integer> ids;
   ...
   }

   public class CustomOrders extends Orders{
   
   private int uid;
   private String username;// 用户姓名
   private String sex;// 性别
   private Date birthday;// 生日
   private String address;// 地址
   }

   public class Orders {
      private Integer id;
   
      private Integer userId;
   
      private String number;
   
      private Date createtime;
   
      private String note;
   
      private User user;
   }

4. Test类

   public class UserMapperTest {
   private SqlSessionFactory factory;
   
   //作用:在测试方法前执行这个方法
   @Before
   public void setUp() throws Exception{
       String resource = "SqlMapConfig.xml";
       //通过流将核心配置文件读取进来
       InputStream inputStream = Resources.getResourceAsStream(resource);
       //通过核心配置文件输入流来创建会话工厂
       factory = new SqlSessionFactoryBuilder().build(inputStream);
   }
   
   @Test
   public void testFindUserByVo() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       QueryVo vo = new QueryVo();
       User user = new User();
       user.setUsername("王");
       user.setSex("1");
       vo.setUser(user);
   
       List<User> list = mapper.findUserbyVo(vo);
       System.out.println(list);
   
   }
   
   @Test
   public void testFindUserCount() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       Integer count = mapper.findUserCount();
       System.out.println("=====" + count);
   }
   
   @Test
   public void testFindUserbyUserNameAndSex() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       User user = new User();
       user.setUsername("王");
       user.setSex("1");
   
       List<User> list = mapper.findUserByUserNameAndSex(user);
   
       System.out.println(list);
   }
   
   @Test
   public void testFindUserbyIds() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       QueryVo vo = new QueryVo();
       List<Integer> ids = new ArrayList<Integer>();
       ids.add(1);
       ids.add(16);
       ids.add(28);
       ids.add(22);
       vo.setIds(ids);
   
       List<User> list = mapper.findUserByIds(vo);
       System.out.println(list);
   }
   
   @Test
   public void testFindOrdersAndUser() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       List<CustomOrders> list = mapper.findOrdersAndUser1();
       System.out.println(list);
   }
   
   @Test
   public void testFindOrdersAnduUser2() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       List<Orders> list = mapper.findOrdersAndUser2();
       System.out.println(list);
   }
   
   @Test
   public void testFindUserAndOrders() throws Exception{
       SqlSession openSession = factory.openSession();
       //通过getMapper方法来实例化接口
       UserMapper mapper = openSession.getMapper(UserMapper.class);
   
       List<User> list = mapper.findUserAndOrders();
       System.out.println(list);
   }
   }

Spring整合

1. Spring配置

   <?xml version="1.0" encoding="UTF-8"?>
   <beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
   xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
   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
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
   http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
   http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
   
   <!-- 加载配置文件 -->
   <context:property-placeholder location="classpath:db.properties" />
   <!-- 数据库连接池 -->
   <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
       destroy-method="close">
       <property name="driverClassName" value="${jdbc.driver}" />
       <property name="url" value="${jdbc.url}" />
       <property name="username" value="${jdbc.username}" />
       <property name="password" value="${jdbc.password}" />
       <property name="maxActive" value="10" />
       <property name="maxIdle" value="5" />
   </bean>
   
   <!-- 整合Sql会话工厂归spring管理 -->
   <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
       <!-- 指定mybatis核心配置文件 -->
       <property name="configLocation" value="classpath:SqlMapConfig.xml"></property>
       <!-- 指定会话工厂使用的数据源 -->
       <property name="dataSource" ref="dataSource"></property>
   </bean>
   
   <!-- 
       配置原生Dao实现   
       注意:class必须指定Dao实现类的全路径名称
   -->
   <bean id="userDao" class="cn.xx.dao.UserDaoImpl">
       <property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
   </bean>
   
   <!-- Mapper接口代理实现 -->
   <!--     <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean"> -->
       <!-- 配置mapper接口的全路径名称 -->
   <!--         <property name="mapperInterface" value="cn.xx.mapper.UserMapper"></property> -->
   <!--         <property name="sqlSessionFactory" ref="sqlSessionFactory"></property> -->
   <!--     </bean> -->
   
   <!-- 使用包扫描的方式批量引入Mapper
   扫描后引用的时候可以使用类名,首字母小写.
    -->
   <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
       <!-- 指定要扫描的包的全路径名称,如果有多个包用英文状态下的逗号分隔 -->
       <property name="basePackage" value="cn.xx.mapper"></property>
   </bean>
   </beans>

2. SqlMapConfig.xml

   <configuration>
   
   
   <typeAliases> 
       <!-- 定义单个pojo类别名
       type:类的全路劲名称
       alias:别名
        -->
   <!--         <typeAlias type="cn.xx.pojo.User" alias="user"/> -->
   
       <!-- 使用包扫描的方式批量定义别名 
       定以后别名等于类名,不区分大小写,但是建议按照java命名规则来,首字母小写,以后每个单词的首字母大写
       -->
       <package name="cn.xx.pojo"/>
   </typeAliases>
   
   <mappers>
       <mapper resource="User.xml"/>
   
       <!-- 
       使用class属性引入接口的全路径名称:
       使用规则:
           1. 接口的名称和映射文件名称除扩展名外要完全相同
           2. 接口和映射文件要放在同一个目录下
        -->
   <!--         <mapper class="cn.xx.mapper.UserMapper"/> -->
   
       <!-- 使用包扫描的方式批量引入Mapper接口 
               使用规则:
               1. 接口的名称和映射文件名称除扩展名外要完全相同
               2. 接口和映射文件要放在同一个目录下
       -->
   <!--         <package name="cn.xx.mapper"/> -->
   </mappers>
   </configuration>

3. User.xml

   <mapper namespace="test">
   
   <select id="findUserById" parameterType="java.lang.Integer" resultType="cn.xx.pojo.User">
       select * from user where id=#{id}
   </select>
   
   <select id="findUserByUserName" parameterType="java.lang.String" resultType="cn.xx.pojo.User">
       select * from user where username like '%${value}%'
   </select>
   
   <insert id="insertUser" parameterType="cn.xx.pojo.User" >
       <!-- 执行 select LAST_INSERT_ID()数据库函数,返回自增的主键
       keyProperty:将返回的主键放入传入参数的Id中保存.
       order:当前函数相对于insert语句的执行顺序,在insert前执行是before,在insert后执行是AFTER
       resultType:id的类型,也就是keyproperties中属性的类型
       -->
       <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer">
           select LAST_INSERT_ID()
       </selectKey>
       insert into user (username,birthday,sex,address) values(#{username},#{birthday},#{sex},#{address})
   </insert>
   
   <delete id="delUserById" parameterType="int">
       delete from user where id=#{id}
   </delete>
   
   <update id="updateUserById" parameterType="cn.xx.pojo.User">
       update user set username=#{username} where id=#{id}
   </update>
   </mapper>

   实现类：

   public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {
   
   @Override
   public User findUserById(Integer id) {
       //sqlSesion是线程不安全的,所以它的最佳使用范围在方法体内
       SqlSession openSession = this.getSqlSession();
       User user = openSession.selectOne("test.findUserById", id);
       //整合后会话归spring管理,所以不需要手动关闭.
       //openSession.close();
       return user;
   }
   
   @Override
   public List<User> findUserByUserName(String userName) {
       SqlSession openSession = this.getSqlSession();
       List<User> list = openSession.selectList("test.findUserByUserName", userName);
       return list;
   }
   }

   Test类：

   public class UserDaoTest {
   
   private ApplicationContext applicatonContext;
   
   @Before
   public void setUp() throws Exception{
       String configLocation = "classpath:ApplicationContext.xml";
       applicatonContext = new ClassPathXmlApplicationContext(configLocation);
   }
   
   @Test
   public void testFindUserById() throws Exception{
       //获取UserDao对象, getBean中的字符串是在ApplicationContext.xml中声明的
       UserDao userDao = (UserDao)applicatonContext.getBean("userDao");
   
       User user = userDao.findUserById(1);
       System.out.println(user);
   }
   }

整合Mapper代理接口

1. Spring配置在上面的配置文件中

2. 测试类：

   public class UserMapperTest {
   private ApplicationContext applicatonContext;
   
   @Before
   public void setUp() throws Exception{
       String configLocation = "classpath:ApplicationContext.xml";
       applicatonContext = new ClassPathXmlApplicationContext(configLocation);
   }
   
   //   @Test
   //   public void  testFindUserById() throws Exception{
   //       UserMapper userMapper = (UserMapper)applicatonContext.getBean("userMapper");
   //       
   //       User user = userMapper.findUserById(1);
   //       System.out.println(user);
   //   }
   
   @Test
   public void testFindUserById() throws Exception{
       UserMapper userMapper = (UserMapper)applicatonContext.getBean("userMapper");
   
       User user = userMapper.selectByPrimaryKey(1);
       System.out.println(user);
   }
   
   @Test
   public void testFindUserAndSex() throws Exception{
       UserMapper userMapper = (UserMapper)applicatonContext.getBean("userMapper");
   
       //创建UserExample对象
       UserExample userExample = new UserExample();
       //通过UserExample对象创建查询条件封装对象(Criteria中是封装的查询条件)
       Criteria createCriteria = userExample.createCriteria();
   
       //加入查询条件
       createCriteria.andUsernameLike("%王%");
       createCriteria.andSexEqualTo("1");
   
       List<User> list = userMapper.selectByExample(userExample);
       System.out.println(list);
   }
   }

   ​