Mybatis入门教程

男娘i 2022-05-03 17:28 297阅读 0赞

本项目是建立在Maven项目基础上的，也可以建立java项目，[ mybatis-x.x.x.jar ][mybatis-x.x.x.jar]下载Jar包，将项目所需Jar包拷贝到项目中即可

**项目板块图**  
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**1.[maven在线搜索][maven]maven中Mybatis的依赖，将依赖拷贝到pom.xml文件中，并保存（小编第一次下载没有成功，去maven的本地仓库删除再重新保存pom.xml下载一次）**

pom.xml

<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/maven-v4_0_0.xsd">
    	<modelVersion>4.0.0</modelVersion>
    	<groupId>Mybatis_01</groupId>
    	<artifactId>Mybatis_01</artifactId>
    	<packaging>war</packaging>
    	<version>0.0.1-SNAPSHOT</version>
    	<name>Mybatis_01 Maven Webapp</name>
    	<url>http://maven.apache.org</url>
    	<dependencies>
    		<dependency>
    			<groupId>junit</groupId>
    			<artifactId>junit</artifactId>
    			
    			<version>4.12</version>
    			<scope>test</scope>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.mybatis</groupId>
    			<artifactId>mybatis</artifactId>
    			<version>3.4.1</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>mysql</groupId>
    			<artifactId>mysql-connector-java</artifactId>
    			<version>5.1.43</version>
    		</dependency>
    
    	</dependencies>
    	<build>
    		<finalName>Mybatis_01</finalName>
    	</build>
    </project>

**2.在resource目录下新建mybatis-config.xml**

此文件是Mybatis的核心配置文件，包括其使用的数据源和事务管理和映射

<?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>
    	
    	<typeAliases>
            <package name="com.mybatis.entity"/>
    	</typeAliases>
    	<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/zs?characterEncoding=utf-8" />
    				<property name="username" value="root" />
    				<property name="password" value="1234" />
    			</dataSource>
    		</environment>
    	</environments>
    	<mappers>
    		<mapper resource="com/mybatis/entity/Author.xml" />
    	</mappers>
    </configuration>

**3.新建com.mybatis.entity包，并在其目录下新建Author.java（实体类）**  
Author.java

package com.mybatis.entity;
    /** * * @ClassName: Author * @Description:作者实体类 * @author 小思 * @date 2018年10月27日 下午8:23:27 * */
    public class Author { 
    	
    	private Integer aid;//作者id
    	private String aname;//作者姓名
    	
    	public Integer getAid() { 
    		return aid;
    	}
    	public void setAid(Integer aid) { 
    		this.aid = aid;
    	}
    	public String getAname() { 
    		return aname;
    	}
    	public void setAname(String aname) { 
    		this.aname = aname;
    	}
    	public Author(Integer aid, String aname) { 
    		super();
    		this.aid = aid;
    		this.aname = aname;
    	}
    	public Author(String aname) { 
    		super();
    		this.aname = aname;
    	}
    	public Author() { 
    		super();
    	}
    	@Override
    	public String toString() { 
    		return "Author [aid=" + aid + ", aname=" + aname + "]";
    	}
    	
    	
    	
    	
    
    }

**4.新建com.mybatis.dao包，并在其目录下新建AuthorDao.java（映射接口）**

AuthorDao.java

package com.mybatis.dao;
    /** * * @ClassName: AuthorDao * @Description:作者类的dao方法的接口，合理描述方法的参数和返回值的接口，方法名映射Author.xml里面的id * @author 小思 * @date 2018年10月27日 下午8:27:09 * */
    
    import java.util.List;
    
    import com.mybatis.entity.Author;
    
    public interface AuthorDao { 
    	/** * * @Title: getAll * @Description:查询所有的作者 * @return * @return List<Author> */
    	public List<Author> getAll();
    	
    	/** * * @Title: findAuthorById * @Description:通过作者的Id查找作者 * @return * @return Author */
    	public Author findAuthorById(int aid);
    	
    	/** * * @Title: addAuthor * @Description:添加作者 * @param author * @return * @return Author */
    	public void addAuthor(Author author);
    	
    	/** * * @Title: updAuthor * @Description:修改作者 * @param author * @return * @return void */
    	public void updAuthor(Author author);
    	
    	/** * * @Title: delAuthor * @Description:删除作者 * @param aid * @return void */
    	public void delAuthor(int aid);
    
    }

**5.在com.mybatis.entity包的目录下新建Author.xml（数据库操作和java方法的映射文件）**  
Author.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="com.mybatis.dao.AuthorDao">
      
      <select id="getAll" resultType="Author">
        select * from Author
      </select>
      <select id="findAuthorById" resultType="Author" parameterType="int">
        select * from Author where aid=#{aid}
      </select>
      <insert id="addAuthor" parameterType="Author">
        insert into author(aname) values(#{aname})
      </insert>
      <update id="updAuthor" parameterType="Author">
        update author set aname=#{aname} where aid=#{aid}
      </update>
      <delete id="delAuthor" parameterType="int">
        delete from author where aid=#{aid}
      </delete>
    </mapper>

**6.在src/test/java目录下新建com.mybatis包，并在其目录下新建TestMybatis.java（单元测试类）**

package com.mybatis;
    
    import java.util.List;
    
    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 com.mybatis.dao.AuthorDao;
    import com.mybatis.entity.Author;
    
    public class TestMybatis { 
    	private SqlSessionFactory sessionFactory;
    	private SqlSession session;
    
    	@Before
    	public void before() { 
    		// 通过获取对象当前的类类型获取当前类型的类加载器来加载类类路径下的资源文件以此构建SqlSessionFactory
    		sessionFactory = new SqlSessionFactoryBuilder()
    				.build(getClass().getClassLoader().getResourceAsStream("mybatis-config.xml"));
    		// 创建SqlSession实例来自行数据库的所有方法和sql语句
    		session = sessionFactory.openSession();
    	}
    
    	@Test
    	public void test() { 
    		// 映射器是一个你创建来绑定你映射的语句的接口，调用合理描述参数和返回值的接口来获取相应的方法
    		AuthorDao authorDao = session.getMapper(AuthorDao.class);
    // // 查询全部的作者
    // List<Author> list = authorDao.getAll();
    // for (Author author : list) { 
    // System.out.println(author);
    // }
    
    // // 通过作者的Id查找作者
    // Author author=authorDao.findAuthorById(1);
    // System.out.println(author);
    		
    // //添加作者
    // Author author=new Author("王麻子");
    // authorDao.addAuthor(author);
    // System.out.println("添加成功");
    		
    // //修改作者
    // Author author=new Author(1,"王六");
    // authorDao.updAuthor(author);
    // System.out.println("修改成功");
    		
    		//删除作者
    		authorDao.delAuthor(4);
    		System.out.println("删除成功");
    
    	}
    
    	@After
    	public void after() { 
    		// 保持SqlSession 的实例是线程安全的，使用完之后关闭sqlSession数据库资源
    		session.commit();
    		session.close();
    
    	}
    
    }

此博文是最基础的Mybatis项目应用，基础请查看[官网][Link 1]了解更多使用与操作

此博文的具体项目和Mysql表格我已上传，需要的伙伴可以自行下载，[下载地址][Link 2]

**说在最后的话：编写实属不易，若喜欢或者对你有帮助记得点赞+关注或者收藏哦~**

[mybatis-x.x.x.jar]: https://github.com/mybatis/mybatis-3/releases
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3plYWw5cw_size_27_color_FFFFFF_t_70]: /images/20220503/acc9e62ab6354fa78d0f60235cdb7fc9.png
[maven]: https://mvnrepository.com/
[Link 1]: http://www.mybatis.org/mybatis-3/zh/index.html
[Link 2]: https://download.csdn.net/download/zeal9s/10748791