Mybatis调用操作-入门

文章目录

文件结构对象类和Mapper接口编写调用类步骤说明

参考网址：https://mybatis.org/mybatis-3/zh/getting-started.html 接上一个JDBC数据库操作之后，然后使用Mybatis进行数据库操作。 https://github.com/mybatis/mybatis-3/releases

文件结构

配置文件 pom.xml

<?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"> <parent> <artifactId>mybatissimple01</artifactId> <groupId>com.ycxy</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>mybatis01</artifactId> <dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.4</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.19</version> </dependency> </dependencies> </project>

resources mybatis-config.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.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://192.168.172.130:3306/mybatis"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <mappers> <mapper resource="Websites.xml"/> </mappers> </configuration>

Mapper文件Websites.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.ycxy.WebsitesMapper"> <select id="selectOne" resultType="com.ycxy.Websites"> select * from websites where id = #{id} </select> </mapper>

对象类和Mapper接口

Websites.java

package com.ycxy; public class Websites { private int id; private String name ; private String url; private int alexa; private String country; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public int getAlexa() { return alexa; } public void setAlexa(int alexa) { this.alexa = alexa; } public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } @Override public String toString() { return "id:"+id + " name: "+ name + " url: " + url; } }

WebsitesMapper.java

package com.ycxy; import java.util.List; public interface WebsitesMapper { public Websites selectOne(int id); }

编写调用类

package com.ycxy; 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 java.io.InputStream; public class MybatisStudy { public static void main(String[] args) throws Exception { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); SqlSession session = sqlSessionFactory.openSession(); //以前的版本 //Websites websites = (Websites) session.selectOne("com.ycxy.WebsitesMapper.selectOne", 1); WebsitesMapper mapper = session.getMapper(WebsitesMapper.class); Websites websites = mapper.selectOne(1); System.out.println(websites.toString()); session.close(); inputStream.close(); } }

id:1 name: Google url: https://www.google.cm/

步骤说明

每个基于 MyBatis 的应用都是以一个 SqlSessionFactory 的实例为核心的。SqlSessionFactory 的实例可以通过 SqlSessionFactoryBuilder 获得。而 SqlSessionFactoryBuilder 则可以从 XML 配置文件或一个预先配置的 Configuration 实例来构建出 SqlSessionFactory 实例。从 SqlSessionFactory 中获取 SqlSessionWebsitesMapper mapper = session.getMapper(WebsitesMapper.class);mapper 调用方法