1.创建maven工程并导入坐标
<?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">
<!-- mybatis的主配置文件 -->
<configuration>
<!-- 配置环境 -->
<environments default="mysql">
<!-- 配置mysql环境 -->
<environment id="mysql">
<!-- 事物类型 -->
<transactionManager type="JDBC"></transactionManager>
<!-- 配置数据源(连接池) -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/eesy_mybatis" />
<property name="username" value="root" />
<property name="password" value="123456" />
</dataSource>
</environment>
</environments>
<!-- 指定映射配置文件的位置,映射配置文件指的是dao独立的配置文件-->
<mappers>
<mapper resource="com/itheima/dao/IUserDao.xml"/>
</mappers>
</configuration>
2.创建实体类和dao的接口
package com.itheima.domain;
import java.io.Serializable;
import java.util.Date;
public class User implements Serializable {
private Integer id;
private String username;
private Date birthday;
private String sex;
private String address;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", birthday=" + birthday +
", sex='" + sex + '\'' +
", address='" + address + '\'' +
'}';
}
}
package com.itheima.domain;
import java.util.List;
/**
* @author 黑马程序员
* @Company
*/
public class QueryVo {
private User user;
private List<Integer> ids;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public List<Integer> getIds() {
return ids;
}
public void setIds(List<Integer> ids) {
this.ids = ids;
}
}
package com.itheima.dao;
import com.itheima.domain.QueryVo;
import com.itheima.domain.User;
import java.util.List;
public interface IUserDao {
List<User> findAll();
List<User> findByCondition(User user);
List<User> findInIds(QueryVo vo);
}
3.创建Mybatis的主配置文件
<?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">
<!-- mybatis的主配置文件 -->
<configuration>
<!-- 配置环境 -->
<environments default="mysql">
<!-- 配置mysql环境 -->
<environment id="mysql">
<!-- 事物类型 -->
<transactionManager type="JDBC"></transactionManager>
<!-- 配置数据源(连接池) -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/eesy_mybatis" />
<property name="username" value="root" />
<property name="password" value="123456" />
</dataSource>
</environment>
</environments>
<!-- 指定映射配置文件的位置,映射配置文件指的是dao独立的配置文件-->
<mappers>
<mapper resource="com/itheima/dao/IUserDao.xml"/>
</mappers>
</configuration>
4.创建映射配置文件
<?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="com.itheima.dao.IUserDao">
<!-- 配置查询所有 -->
<select id="findAll" resultType="com.itheima.domain.User">
select * from user;
</select>
<select id="findByCondition" resultType="com.itheima.domain.User">
<!-- select * from user where 1=1
<if test="username!= null">
and username = #{username}
</if>
<if test="sex!=null">
and sex = #{sex}
</if>-->
-- 不写where1=1
select * from user
<where>
<if test="username!= null">
and username = #{username}
</if>
<if test="sex!=null">
and sex = #{sex}
</if>
</where>
</select>
<select id="findInIds" resultType="com.itheima.domain.User" parameterType="com.itheima.domain.QueryVo">
<!--<include refid="defaultUser"></include>-->
select * from user
<where>
<if test="ids != null and ids.size()>0">
<foreach collection="ids" open="and id in (" close=")" item="id" separator=",">
#{id}
</foreach>
</if>
</where>
</select>
</mapper>
5.测试程序
package com.itheima.test;
import com.itheima.dao.IUserDao;
import com.itheima.domain.QueryVo;
import com.itheima.domain.User;
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.After;
import org.junit.Before;
import org.junit.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class MybatisTest {
private InputStream in;
private SqlSession sqlSession;
private IUserDao userDao;
@Before
public void init() throws IOException {
// 1.读取文件
in = Resources.getResourceAsStream("SqlMapConfig.xml");
// 2.创建SqlSessionFactory工厂
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
// 3.使用工厂生产SQLSession对象
sqlSession = factory.openSession(true);
// 4.使用SQLSession创建Dao接口的代理对象
userDao = sqlSession.getMapper(IUserDao.class);
}
@After
public void destroy() throws IOException {
// 提交事务
// sqlSession.commit();
// 关闭资源
sqlSession.close();
in.close();
}
/**
* 查询所有用户
*/
@Test
public void findAll() throws IOException {
List<User> users = userDao.findAll();
for (User user : users) {
System.out.println(user);
}
}
/**
* 测试查询所有
*/
@Test
public void testFindByCondition() {
User u = new User();
u.setUsername("老王");
// u.setSex("女");
//5.执行查询所有方法
List<User> users = userDao.findByCondition(u);
for (User user : users) {
System.out.println(user);
}
}
/**
* 测试查询所有
*/
@Test
public void testFindInIds() {
QueryVo qo = new QueryVo();
List<Integer> list = new ArrayList<Integer>();
list.add(41);
list.add(42);
list.add(46);
qo.setIds(list);
//5.执行查询所有方法
List<User> users = userDao.findInIds(qo);
for (User user : users) {
System.out.println(user);
}
}
}