MyBatis
简介
MyBatis 是一款为了让服务更好使用关系型数据库的框架。
使用方式
至少引入如下依赖：
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| dependencies {
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.mybatis.spring.boot:mybatis-spring-boot-starter:3.0.4'
compileOnly 'org.projectlombok:lombok'
annotationProcessor 'org.projectlombok:lombok'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
testImplementation 'org.mybatis.spring.boot:mybatis-spring-boot-starter-test:3.0.4'
runtimeOnly 'com.mysql:mysql-connector-j'
testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
}
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然后编写如下配置 application.yaml ：
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| spring:
datasource:
url: jdbc:mysql://xxx.xxx.xxx.xxx:3306/sakila
username: xxxx
password: xxxx
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
configuration:
map-underscore-to-camel-case: true
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注：此处为了便捷选了 MySQL 提供的示例数据库 sakila 。
之后编写如下代码 Actor.java ：
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| import lombok.Data;
import java.io.Serializable;
import java.time.LocalDateTime;
@Data
public class Actor implements Serializable {
private Integer actorId;
private String firstName;
private String lastName;
private LocalDateTime lastUpdate;
}
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然后编写 ActorMapper.java :
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| import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import java.util.List;
@Mapper
public interface ActorMapper {
@Select("SELECT * FROM actor")
List<Actor> findAll();
}
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之后修改主类即可：
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| import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Application implements CommandLineRunner {
private final ActorMapper actorMapper;
public Application(ActorMapper actorMapper) {
this.actorMapper = actorMapper;
}
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
@Override
public void run(String... args) throws Exception {
System.out.println(this.actorMapper.findAll());
}
}
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其他插件
MyBatis Generator
从 Maven 上直接下载 mybatis-generator-core 的 jar 包和数据库驱动包，然后将其放置在同一目录下。
之后结合实际场景修改配置文件即可，样例如下：
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| <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<classPathEntry location="mysql-connector-j-9.1.0.jar" />
<context id="DB2Tables" targetRuntime="MyBatis3">
<jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
connectionURL="jdbc:mysql://xxx.xxx.xxx.xxx:3306/sakila?useSSL=false"
userId="xxxx"
password="xxxx">
</jdbcConnection>
<javaTypeResolver >
<property name="forceBigDecimals" value="false" />
</javaTypeResolver>
<javaModelGenerator targetPackage="test.model" targetProject=".">
<property name="enableSubPackages" value="true" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<sqlMapGenerator targetPackage="test.xml" targetProject=".">
<property name="enableSubPackages" value="true" />
</sqlMapGenerator>
<javaClientGenerator type="XMLMAPPER" targetPackage="test.dao" targetProject=".">
<property name="enableSubPackages" value="true" />
</javaClientGenerator>
<table schema="sakila" tableName="actor" domainObjectName="Actor"/>
</context>
</generatorConfiguration>
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参考资料
Java & Databases: An Overview of Libraries & APIs
官方网站
官方项目
示例代码
MyBatis Generator