spring boot中mybatis使用
文章目錄
- spring boot中mybatis使用
-
-
- 一、簡介
- 二、開發步驟
-
- 2.1 mybatis generator使用
-
- 2.1.1 mybatis generator源碼位址
- 2.1.2 定義generatorConfig.xml配置檔案
- 2.1.3 添加mybatis-generator-maven-plugin插件
- 2.1.4 生成映射檔案
- 2.2 mybatis使用
-
- 2.2.1 application.yaml添加配置
- 2.2.2 在啟動類添加注解@MapperScan
- 2.2.3 mapper映射檔案
- 三、示例
-
- 3.1 添加maven依賴
- 3.2 添加application.yaml配置
- 3.3 啟動類添加@MapperScan注解配置
- 3.4 添加自定義mapper
- 3.5 測試
-
一、簡介
這裡介紹在spring boot中資料持久化mybatis使用,包含使用插件mybatis generator自動生成映射等相關檔案。
二、開發步驟
2.1 mybatis generator使用
這裡介紹使用mybatis generator的maven插件生成對應的entity、mapper接口及mapper的xml映射檔案。
2.1.1 mybatis generator源碼位址
mybatis generator源碼位址:https://github.com/mybatis/generator,可以根據需要調整源碼位址,這塊後續再介紹。
2.1.2 定義generatorConfig.xml配置檔案
generatorConfig.xml配置檔案定義了生成映射檔案的相關屬性,哪些表需要生成對應映射檔案。可在idea中定義為模闆檔案,generatorConfig.xml配置檔案示例如下:
<?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>
<!-- targetRuntime:指定生成檔案比對的mybatis版本 -->
<context id="default" targetRuntime="MyBatis3">
<!-- bug修複插件,用于避免mapper xml檔案内元素重複生成-->
<plugin type="org.mybatis.generator.plugins.UnmergeableXmlMappersPlugin"></plugin>
<!-- 自帶的分頁插件-->
<plugin type="org.mybatis.generator.plugins.RowBoundsPlugin"></plugin>
<!--建立class時,對注釋進行控制-->
<commentGenerator>
<property name="suppressDate" value="true"/>
<!--是否去除自動生成的注釋,true:是 false:否 -->
<property name="suppressAllComments" value="true"/>
</commentGenerator>
<!--jdbc的資料庫連接配接資訊-->
<jdbcConnection driverClass="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/school?useUnicode=true&characeterEncoding=utf-8&serverTimezone=UTC"
userId="root"
password="root"></jdbcConnection>
<!-- 類型處理器,在資料庫類型和java類型之間的轉換控制-->
<javaTypeResolver>
<!-- 是否強制資料庫中的decimal、numeric類型,轉換為java中的BigDecimal類,預設是false,通常不需要修改-->
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!--targetPackage:生成實體類所在的包 targetProject:生成實體類所在的檔案位置 -->
<javaModelGenerator targetPackage="com.dragon.study.spring_boot_mybatis.entity"
targetProject="src/main/java">
<!-- 是否允許子包 -->
<property name="enableSubPackages" value="false"/>
<!-- 是否對modal添加構造函數 -->
<property name="constructorBased" value="true"/>
<!-- 是否清理從資料庫中查詢出的字元串左右兩邊的空白字元 -->
<property name="trimStrings" value="true"/>
<!-- 建立modal對象是否不可改變 即生成的modal對象不會有setter方法,隻有構造方法 -->
<property name="immutable" value="false"/>
</javaModelGenerator>
<!--targetPackage:生成mapper的xml檔案所在的包 targetProject:生成mapper的xml檔案位置 -->
<sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">
<!-- 針對資料庫的一個配置,是否把 schema 作為字包名 -->
<property name="enableSubPackages" value="false"/>
</sqlMapGenerator>
<!--targetPackage:生成mapper接口所在的包 targetProject:生成mapper接口的檔案位置 -->
<javaClientGenerator type="XMLMAPPER"
targetPackage="com.dragon.study.spring_boot_mybatis.dao" targetProject="src/main/java">
<!-- 針對 oracle 資料庫的一個配置,是否把 schema 作為字包名 -->
<property name="enableSubPackages" value="false"/>
</javaClientGenerator>
<!--指定需要生成的資料庫表和java中對應的實體bean名,另外還有其它屬性可配置,在此略過-->
<table tableName="stu" domainObjectName="Stu"></table>
</context>
</generatorConfiguration>
2.1.3 添加mybatis-generator-maven-plugin插件
在maven的pom.xml檔案中添加mybatis-generator-maven-plugin插件,如下:
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.4.0</version>
<configuration>
<!-- 在控制台列印執行日志 -->
<verbose>true</verbose>
<!-- 重複生成時會覆寫之前的檔案-->
<overwrite>true</overwrite>
<configurationFile>src/main/resources/generatorConfig.xml</configurationFile>
</configuration>
<!-- 資料庫連接配接選擇8.0以上的,因為用的mysql8.0-->
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.21</version>
</dependency>
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.4.0</version>
</dependency>
</dependencies>
</plugin>
2.1.4 生成映射檔案
執行mybatis-generator插件即可生成相應映射檔案,如在idea中輕按兩下項目對應的maven Plugins下的mybatis-generator即可。
2.2 mybatis使用
2.2.1 application.yaml添加配置
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
url: jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=UTF-8
username: root
password: root
driverClassName: com.mysql.jdbc.Driver
mybatis:
type-aliases-package: com.dragon.study.spring_boot_mybatis.entity
mapper-locations: classpath:mapper/*.xml
configuration:
map-underscore-to-camel-case: true
logging:
level:
com.dragon.study.spring_boot_mybatis.dao: debug
2.2.2 在啟動類添加注解@MapperScan
在在啟動類添加指定包位置的注解@MapperScan,如:
2.2.3 mapper映射檔案
根據前面mybatis-generator方法生成對應映射檔案,也可使用@Select、@MapKey等注解生成自定義mapper接口方法。
三、示例
3.1 添加maven依賴
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.dragon.study</groupId>
<artifactId>spring_boot_mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring_boot_mybatis</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.3</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.10</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.4.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.4.0</version>
<configuration>
<!-- 在控制台列印執行日志 -->
<verbose>true</verbose>
<!-- 重複生成時會覆寫之前的檔案-->
<overwrite>true</overwrite>
<configurationFile>src/main/resources/generatorConfig.xml</configurationFile>
</configuration>
<!-- 資料庫連接配接選擇8.0以上的,因為用的mysql8.0-->
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.21</version>
</dependency>
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.4.0</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</project>
3.2 添加application.yaml配置
server:
port: 11001
spring:
application:
name: spring-boot-mybatis
datasource:
type: com.alibaba.druid.pool.DruidDataSource
url: jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=UTF-8
username: root
password: root
driverClassName: com.mysql.jdbc.Driver
mybatis:
type-aliases-package: com.dragon.study.spring_boot_mybatis.entity
mapper-locations: classpath:mapper/*.xml
configuration:
map-underscore-to-camel-case: true
logging:
level:
com.dragon.study.spring_boot_mybatis.dao: debug
3.3 啟動類添加@MapperScan注解配置
package com.dragon.study.spring_boot_mybatis;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
//指定mapper包
@MapperScan(basePackages = "com.dragon.study.spring_boot_mybatis.dao")
public class SpringBootMybatisApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootMybatisApplication.class, args);
}
}
3.4 添加自定義mapper
根據mybatis-generator插件即可生成相應映射檔案,在此略。自定義mapper如下:
package com.dragon.study.spring_boot_mybatis.dao;
import com.dragon.study.spring_boot_mybatis.entity.Stu;
import org.apache.ibatis.annotations.MapKey;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import java.util.Map;
public interface CustomStuMapper {
@MapKey("id")
@Select("select * from stu where id>#{id}")
Map<Integer, Stu> selectStuMapGreaterId(@Param("id") int id);
}
3.5 測試
package com.dragon.study.spring_boot_mybatis;
import com.dragon.study.spring_boot_mybatis.dao.CustomStuMapper;
import com.dragon.study.spring_boot_mybatis.dao.StuMapper;
import com.dragon.study.spring_boot_mybatis.entity.Stu;
import com.dragon.study.spring_boot_mybatis.entity.StuExample;
import org.apache.ibatis.session.RowBounds;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import javax.annotation.Resource;
import java.util.List;
import java.util.Map;
@SpringBootTest
class SpringBootMybatisApplicationTests {
@Resource
private StuMapper stuMapper;
@Resource
private CustomStuMapper customStuMapper;
@Test
void contextLoads() {
//根據主鍵查詢
Stu stu = stuMapper.selectByPrimaryKey(1);
System.out.println(stu);
//分頁查詢
List<Stu> stuList = stuMapper.selectByExampleWithRowbounds(new StuExample(), new RowBounds(10, 5));
System.out.println(stuList);
//調用自定義mapper
Map<Integer, Stu> m = customStuMapper.selectStuMapGreaterId(90);
System.out.println(m);
}
}