Mybatis入门配置，详解。

以你之姓@ 2022-05-18 08:35 154阅读 0赞

# 目的：使用mybatis用id查询数据 #

### 第一步：导入相对应的jar包 ###

![70][]

### 第二步：配置dtd约束（只有配置了约束才可以进行xml自动提示） ###

[https://blog.csdn.net/a15920804969/article/details/79107852][https_blog.csdn.net_a15920804969_article_details_79107852]

### 第三步：准备好一张表，和相对应的pojo（domain） ###

3-1、user表

![70 1][]

3-2、pojo

package com.ziyang.mybatis.pojo;
    
    import java.io.Serializable;
    import java.util.Date;
    
    public class User implements Serializable {
    	/**
    	 * 
    	 */
    	private static final long serialVersionUID = 1L;
    	private Integer id;
    	private String username;
    	private String sex;
    	private Date birthday;
    	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 String getSex() {
    		return sex;
    	}
    	public void setSex(String sex) {
    		this.sex = sex;
    	}
    	public Date getBirthday() {
    		return birthday;
    	}
    	public void setBirthday(Date birthday) {
    		this.birthday = birthday;
    	}
    	public String getAddress() {
    		return address;
    	}
    	public void setAddress(String address) {
    		this.address = address;
    	}
    	@Override
    	public String toString() {
    		return "User [id=" + id + ", username=" + username + ", sex=" + sex
    				+ ", birthday=" + birthday + ", address=" + address + "]";
    	}
    
    	
    	
    
    }

### 第四步：sqlmap的创建（也就是写sql语句的地方） ###

<?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="test">
    	
    	
    	<select id="findUserById" parameterType="Integer" resultType="com.ziyang.mybatis.pojo.User">
    		select * from user where id = #{a}
    	</select>
    	
    </mapper>

### 第五步：配置mybatis主配置文件 （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">
    <configuration>
    
    	
    	<environments default="development">
    		<environment id="development">
    			
    			<transactionManager type="JDBC" />
    			
    			<dataSource type="POOLED">
    				<property name="driver" value="com.mysql.jdbc.Driver" />
    				<property name="url"
    					value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8" />
    				<property name="username" value="root" />
    				<property name="password" value="123" />
    			</dataSource>
    		</environment>
    	</environments>
    	
    	
    	<mappers>
    		<mapper resource="com/ziyang/mybatis/sqlmap/User.xml"/>
    	</mappers>
    	
    </configuration>

### 第六步：测试： ###

package com.ziyang.mybatis.test;
    
    import java.io.IOException;
    import java.io.InputStream;
    
    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 com.ziyang.mybatis.pojo.User;
    
    public class Demo_1 {
    	
    	@Test
    	public void test1() throws IOException {
    		//加载核心配置文件
    		InputStream stream = Resources.getResourceAsStream("sqlMapConfig.xml");
    		//创建一个sqlSessionFactory
    		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(stream);
    		//创建sqlsession
    		SqlSession sqlSession = sqlSessionFactory.openSession();
    		//执行sql语句
    		User user = sqlSession.selectOne("test.findUserById",1);
    		
    		System.out.println(user);
    	}
    }

## 结构目录： ##

![70 2][]

[70]: /images/20220518/73fbfa4424514a85b046900af0e21f88.png
[https_blog.csdn.net_a15920804969_article_details_79107852]: https://blog.csdn.net/a15920804969/article/details/79107852
[70 1]: /images/20220518/f1f485e94bc044fdaf81030a020457b2.png
[70 2]: /images/20220518/c6270eaddff64313b1db5caa68eb7a81.png