Mybatis 环境搭建（使用sqlSession代理，不使用dao实现）
这边先介绍mybatis 不实现dao,使用SqlSession.getMapper(Clazz)代理的方式的环境搭建。
- 创建maven 工程，导入相应的jar 依赖
- 准备测试数据文件User以及UserDao
- 准备主配置文件SqlMapConfig.xml和mapping.xml
- 编写测试代码----
下面上代码
1）pom.xml 依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.hs</groupId>
<artifactId>mybatistype</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.32</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
</dependencies>
</project>2）创建User实体类和UserDao 接口，注意这里User实体类属性最好与数据库字段名相对应方便开发
以下为数据库sql:
CREATE DATABASE mybatis;
USE mybatis
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`username` VARCHAR(32) NOT NULL COMMENT '用户名称',
`birthday` DATETIME DEFAULT NULL COMMENT '生日',
`sex` CHAR(1) DEFAULT NULL COMMENT '性别',
`address` VARCHAR(256) DEFAULT NULL COMMENT '地址',
PRIMARY KEY (`id`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
------------------------------------------------------------------------------------
以下为User实体类
------------------------------------------------------------------------------------
package domain;
import java.util.Date;
/**
* @Author: huangshun
* @Date: 2019/4/29 15:19
* @Version 1.0
*/
public class User {
/*
* `id` INT(11) NOT NULL AUTO_INCREMENT,
`username` VARCHAR(32) NOT NULL COMMENT '用户名称',
`birthday` DATETIME DEFAULT NULL COMMENT '生日',
`sex` CHAR(1) DEFAULT NULL COMMENT '性别',
`address` VARCHAR(256) DEFAULT NULL COMMENT '地址',*/
private Integer id;
private String username;
private Date birthday;
private String sex;
private String address;
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", birthday=" + birthday +
", sex='" + sex + '\'' +
", address='" + 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;
}
}
以下为UserDao接口
----------------------------------------------------------------------------------------
package dao;
import domain.User;
import java.util.List;
/**
* @Author: huangshun
* @Date: 2019/4/29 15:21
* @Version 1.0
*/
public interface UserDao {
List<User> findAll();
}
3)创建SqlMapConfig.xml和 UserDaoMapping.xml
这里是目录结构
SqlMapConfig.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">
<!-- 主配置文件-->
<configuration>
<environments default="mysql">
<environment id="mysql">
<!--选择开始事务的类型 -->
<transactionManager type="JDBC"></transactionManager>
<!--连接池的类型 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="UserDaoMapping.xml"></mapper>
</mappers>
</configuration>
UserDaoMapping.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">
<!-- 这里namespace 为UserDao 的全限定类型 namespace 和下面的id 组成唯一标识-->
<mapper namespace="dao.UserDao">
<!-- id唯一 是UserDao里方法名 与namespace 确定是UserDao里哪个方法-->
<!--resultType:返回值类型，这里返回值类型为User对象 -->
<select id="findAll" resultType="domain.User">
select * from user ;
</select>
</mapper>4)测试测试代码--
import dao.UserDao;
import 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.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
/**
* @Author: huangshun
* @Date: 2019/4/29 15:30
* @Version 1.0
*/
public class TestCrud {
@Test
public void testFindAll() throws IOException {
InputStream in= Resources.getResourceAsStream("SqlMapConfig.xml");
SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(in);
SqlSession sqlSession = factory.openSession();
UserDao dao = sqlSession.getMapper(UserDao.class);
List<User> users = dao.findAll();
for (User user : users) {
System.out.println(user);
}
}
}
--------- 以下是结果
User{id=41, username='11111', birthday=Tue Feb 27 17:47:08 CST 2018, sex='男', address='北京'}
User{id=42, username='小二王', birthday=Fri Mar 02 15:09:37 CST 2018, sex='女', address='北京金燕龙'}
User{id=43, username='小二王', birthday=Sun Mar 04 11:34:34 CST 2018, sex='女', address='北京金燕龙'}
User{id=45, username='传智播客', birthday=Sun Mar 04 12:04:06 CST 2018, sex='男', address='北京金燕龙'}
ok，结束
附录----这里再加上 resultMap 的使用(一般如果实体类属性名与数据库字段名不对应需要这么配置)
以下是userDaoMapping.xml 配置 resultMap 不使用resulttype
<?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">
<!-- 这里namespace 为UserDao 的全限定类型 namespace 和下面的id 组成唯一标识-->
<mapper namespace="dao.UserDao">
<resultMap id="resultMap" type="domain.User">
<!--id 主键字段的对应 -->
<id column="id" property="id"/>
<!--非主键字段的对应 -->
<result column="username" property="username"/>
<result column="sex" property="sex"/>
<result column="birthday" property="birthday"/>
<result column="address" property="address"></result>
</resultMap>
<!-- id唯一 是UserDao里方法名 与namespace 确定是UserDao里哪个方法-->
<!--resultMap:返回值类型，这里返回值类型为上面配置的resultMap对象 即User-->
<select id="findAll" resultMap="resultMap">
select * from user ;
</select>
<!--按条件查询用户 -->
<select id="findByCondition" parameterType="domain.User" resultType="domain.User">
select * from user
<where>
<if test="username!=null"></if>
and username like #{username}
<if test="sex!=null">
and sex =#{sex}
</if>
</where>
</select>
<!--根据id 集合查询用户 -->
<select id="findByIds" resultType="domain.User" parameterType="domain.QueryVo">
select * from user
<where>
<if test="ids !=null and ids.size()>0">
<foreach collection="ids" open="id in (" close=")" item="id" separator="," >
#{id}
</foreach>
</if>
</where>
</select>
</mapper>