SpringBoot集成MyBatis-Plus框架详细方法

1.说明

本文详细介绍Spring Boot集成MyBatis-Plus框架的方法，
使用MySQL数据库进行测试，
包括完整的开发到测试步骤，
从一开始的Spring Boot工程创建，
到MySQL数据库刷库脚本，
到引入mybatis-plus依赖，
然后编写实现代码和配置文件，
最后使用Junit5成功进行测试。

2.创建Spring Boot的Demo工程

首先选择创建Spring Starter Project工程：
File -> New -> Other... -> Spring Boot -> Spring Starter Project

点击Next:

输入工程名称Name:springboot-mybatis-plus，
选择工程本地保存的目录。

点击Next:

先选择Spring Boot Version,
再选择工程需要的依赖：

Spring Web
MySQL Driver
Spring Boot DevTools

点击Finish自动完成工程的创建。

工程创建完毕后，删除不需要的文件和目录：

.mvn
HELP.md
mvnw
mvnw.cmd

3.增加mybatis-plus依赖

在pom.xml中增加mybatis-plus依赖

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.3.2</version>
</dependency>

4.新建application.yml文件

首先删除src\main\resources目录下的文件和目录：

static
templates
application.properties

新建application.yml文件:
File -> New -> Other... -> General -> File

点击Next:

选择在src\main\resources目录下创建文件，
填写文件名application.yml。

5.修改application.yml文件

在application.yml增加配置，
指定服务端口和连接数据库：

server:
  port: 8088

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://10.21.13.14:3306/demodb
    username: demo
    password: demo123456

6.数据库表和脚本

现有一张User表，其表结构如下：

id	ame	age	email
1	Jone	18	test1@baomidou.com
2	Jack	20	test2@baomidou.com
3	Tom	28	test3@baomidou.com
4	Sandy	21	test4@baomidou.com
5	Billie	24	test5@baomidou.com

对应的数据库create_tables.sql脚本如下：

DROP TABLE IF EXISTS TBL_USER;

CREATE TABLE TBL_USER
(
    id BIGINT(20) NOT NULL COMMENT '主键ID',
    name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
    age INT(11) NULL DEFAULT NULL COMMENT '年龄',
    email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
    PRIMARY KEY (id)
);

对应的数据库init_data_user.sql脚本如下：

DELETE FROM TBL_USER;

INSERT INTO TBL_USER (id, name, age, email) VALUES
(1, 'Jone', 18, 'test1@baomidou.com'),
(2, 'Jack', 20, 'test2@baomidou.com'),
(3, 'Tom', 28, 'test3@baomidou.com'),
(4, 'Sandy', 21, 'test4@baomidou.com'),
(5, 'Billie', 24, 'test5@baomidou.com');

7.数据库用户创建和刷库

在MySQL数据库中创建对应的数据库和用户：

CREATE DATABASE demodb;
GRANT ALL ON *.* to 'demo'@'%' identified BY 'demo123456' WITH GRANT OPTION;

然后使用新建的用户执行上面的脚本进行刷库。

8.创建实体类

创建实体类User.java：

package com.example.demo.entity;

import com.baomidou.mybatisplus.annotation.TableName;

@TableName("TBL_USER")
public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", age=" + age + ", email=" + email + "]";
    }
}

注意User类的注解@TableName("TBL_USER")，
表示数据库的表TBL_USER和实体类User对应。

9.创建Mapper类：

在dao层创建Mapper类UserDao.java：

package com.example.demo.dao;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.demo.entity.User;

public interface UserDao extends BaseMapper<User> {

}

注意需要继承BaseMapper<T>泛型类，
并且指定其中T为User类。

10.增加@MapperScan注解

在Spring Boot启动类中增加@MapperScan注解，
用于扫描Mapper文件夹：

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.example.demo.dao")
@SpringBootApplication
public class SpringbootMybatisPlusApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootMybatisPlusApplication.class, args);
    }

}

11.启动Spring Boot

右键启动类SpringbootMybatisPlusApplication.java ->
Run As -> Java Application

启动成功日志：

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.3.1.RELEASE)

2020-07-01 15:34:45.160  INFO 12764 --- [  restartedMain] c.e.d.SpringbootMybatisPlusApplication   : Starting SpringbootMybatisPlusApplication on yuwen-asiainfo with PID 12764 (D:\Code\Learn\SpringBoot\springboot-mybatis-plus\target\classes started by yuwen in D:\Code\Learn\SpringBoot\springboot-mybatis-plus)
2020-07-01 15:34:45.162  INFO 12764 --- [  restartedMain] c.e.d.SpringbootMybatisPlusApplication   : No active profile set, falling back to default profiles: default
2020-07-01 15:34:45.201  INFO 12764 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
2020-07-01 15:34:45.201  INFO 12764 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
2020-07-01 15:34:46.525  INFO 12764 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8088 (http)
2020-07-01 15:34:46.533  INFO 12764 --- [  restartedMain] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2020-07-01 15:34:46.533  INFO 12764 --- [  restartedMain] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.36]
2020-07-01 15:34:46.588  INFO 12764 --- [  restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2020-07-01 15:34:46.589  INFO 12764 --- [  restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1387 ms
2020-07-01 15:34:46.711  INFO 12764 --- [  restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
 _ _   |_  _ _|_. ___ _ |    _
| | |\/|_)(_| | |_\  |_)||_|_\
     /               |
                        3.3.2
2020-07-01 15:34:47.770  INFO 12764 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
2020-07-01 15:34:47.969  INFO 12764 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8088 (http) with context path ''
2020-07-01 15:34:47.978  INFO 12764 --- [  restartedMain] c.e.d.SpringbootMybatisPlusApplication   : Started SpringbootMybatisPlusApplication in 3.105 seconds (JVM running for 3.492)

12.功能测试

首先删除\src\test\java目录下的文件：

SpringbootMybatisPlusApplicationTests.java

添加测试类SampleTest，
进行功能测试：

package com.example.demo;

import java.util.List;

import org.junit.Assert;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import com.example.demo.dao.UserDao;
import com.example.demo.entity.User;

@SpringBootTest
public class SampleTest {

    @Autowired
    private UserDao userDao;

    @Test
    public void testSelect() {
        System.out.println(("----- selectAll method test ------"));
        List<User> userList = userDao.selectList(null);
        Assert.assertEquals(5, userList.size());
        userList.forEach(System.out::println);
    }

}

注意这里使用的是Junit5进行单元测试，
如果是Junit4需要自行修改相关配置。
右键测试类SampleTest -> Run As -> Run Configurations...
可以看到Test Runner使用的是Junit5:

测试用例执行成功日志

15:49:55.334 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating CacheAwareContextLoaderDelegate from class [org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate]
15:49:55.343 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating BootstrapContext using constructor [public org.springframework.test.context.support.DefaultBootstrapContext(java.lang.Class,org.springframework.test.context.CacheAwareContextLoaderDelegate)]
15:49:55.365 [main] DEBUG org.springframework.test.context.BootstrapUtils - Instantiating TestContextBootstrapper for test class [com.example.demo.SampleTest] from class [org.springframework.boot.test.context.SpringBootTestContextBootstrapper]
15:49:55.377 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Neither @ContextConfiguration nor @ContextHierarchy found for test class [com.example.demo.SampleTest], using SpringBootContextLoader
15:49:55.380 [main] DEBUG org.springframework.test.context.support.AbstractContextLoader - Did not detect default resource location for test class [com.example.demo.SampleTest]: class path resource [com/example/demo/SampleTest-context.xml] does not exist
15:49:55.381 [main] DEBUG org.springframework.test.context.support.AbstractContextLoader - Did not detect default resource location for test class [com.example.demo.SampleTest]: class path resource [com/example/demo/SampleTestContext.groovy] does not exist
15:49:55.381 [main] INFO org.springframework.test.context.support.AbstractContextLoader - Could not detect default resource locations for test class [com.example.demo.SampleTest]: no resource found for suffixes {-context.xml, Context.groovy}.
15:49:55.382 [main] INFO org.springframework.test.context.support.AnnotationConfigContextLoaderUtils - Could not detect default configuration classes for test class [com.example.demo.SampleTest]: SampleTest does not declare any static, non-private, non-final, nested classes annotated with @Configuration.
15:49:55.414 [main] DEBUG org.springframework.test.context.support.ActiveProfilesUtils - Could not find an 'annotation declaring class' for annotation type [org.springframework.test.context.ActiveProfiles] and class [com.example.demo.SampleTest]
15:49:55.468 [main] DEBUG org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider - Identified candidate component class: file [D:\Code\Learn\SpringBoot\springboot-mybatis-plus\target\classes\com\example\demo\SpringbootMybatisPlusApplication.class]
15:49:55.469 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Found @SpringBootConfiguration com.example.demo.SpringbootMybatisPlusApplication for test class com.example.demo.SampleTest
15:49:55.547 [main] DEBUG org.springframework.boot.test.context.SpringBootTestContextBootstrapper - @TestExecutionListeners is not present for class [com.example.demo.SampleTest]: using defaults.
15:49:55.547 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener, org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener, org.springframework.boot.test.autoconfigure.webservices.client.MockWebServiceServerTestExecutionListener, org.springframework.test.context.web.ServletTestExecutionListener, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener, org.springframework.test.context.support.DependencyInjectionTestExecutionListener, org.springframework.test.context.support.DirtiesContextTestExecutionListener, org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener, org.springframework.test.context.event.EventPublishingTestExecutionListener]
15:49:55.561 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper - Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@54bff557, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@593aaf41, org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener@5a56cdac, org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener@7c711375, org.springframework.test.context.support.DirtiesContextTestExecutionListener@57cf54e1, org.springframework.test.context.transaction.TransactionalTestExecutionListener@5b03b9fe, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener@37d4349f, org.springframework.test.context.event.EventPublishingTestExecutionListener@434a63ab, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener@6e0f5f7f, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener@2805d709, org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerResetTestExecutionListener@3ee37e5a, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener@2ea41516, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverTestExecutionListener@3a44431a, org.springframework.boot.test.autoconfigure.webservices.client.MockWebServiceServerTestExecutionListener@3c7f66c4]
15:49:55.564 [main] DEBUG org.springframework.test.context.support.AbstractDirtiesContextTestExecutionListener - Before test class: context [DefaultTestContext@550dbc7a testClass = SampleTest, testInstance = [null], testMethod = [null], testException = [null], mergedContextConfiguration = [WebMergedContextConfiguration@21282ed8 testClass = SampleTest, locations = '{}', classes = '{class com.example.demo.SpringbootMybatisPlusApplication}', contextInitializerClasses = '[]', activeProfiles = '{}', propertySourceLocations = '{}', propertySourceProperties = '{org.springframework.boot.test.context.SpringBootTestContextBootstrapper=true}', contextCustomizers = set[org.springframework.boot.test.context.filter.ExcludeFilterContextCustomizer@2f112965, org.springframework.boot.test.json.DuplicateJsonObjectContextCustomizerFactory$DuplicateJsonObjectContextCustomizer@d4342c2, org.springframework.boot.test.mock.mockito.MockitoContextCustomizer@0, org.springframework.boot.test.web.client.TestRestTemplateContextCustomizer@1f0f1111, org.springframework.boot.test.autoconfigure.properties.PropertyMappingContextCustomizer@0, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverContextCustomizerFactory$Customizer@47d90b9e, org.springframework.boot.test.context.SpringBootTestArgs@1], resourceBasePath = 'src/main/webapp', contextLoader = 'org.springframework.boot.test.context.SpringBootContextLoader', parent = [null]], attributes = map['org.springframework.test.context.web.ServletTestExecutionListener.activateListener' -> true]], class annotated with @DirtiesContext [false] with mode [null].
15:49:55.589 [main] DEBUG org.springframework.test.context.support.TestPropertySourceUtils - Adding inlined properties to environment: {spring.jmx.enabled=false, org.springframework.boot.test.context.SpringBootTestContextBootstrapper=true}

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.3.1.RELEASE)

2020-07-01 15:49:55.873  INFO 15452 --- [           main] com.example.demo.SampleTest              : Starting SampleTest on yuwen-asiainfo with PID 15452 (started by yuwen in D:\Code\Learn\SpringBoot\springboot-mybatis-plus)
2020-07-01 15:49:55.874  INFO 15452 --- [           main] com.example.demo.SampleTest              : No active profile set, falling back to default profiles: default
2020-07-01 15:49:56.907  INFO 15452 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
 _ _   |_  _ _|_. ___ _ |    _
| | |\/|_)(_| | |_\  |_)||_|_\
     /               |
                        3.3.2
2020-07-01 15:49:58.403  INFO 15452 --- [           main] com.example.demo.SampleTest              : Started SampleTest in 2.806 seconds (JVM running for 3.564)
----- selectAll method test ------
2020-07-01 15:49:58.602  INFO 15452 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Starting...
2020-07-01 15:49:58.741  INFO 15452 --- [           main] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Start completed.
User [id=1, name=Jone, age=18, email=test1@baomidou.com]
User [id=2, name=Jack, age=20, email=test2@baomidou.com]
User [id=3, name=Tom, age=28, email=test3@baomidou.com]
User [id=4, name=Sandy, age=21, email=test4@baomidou.com]
User [id=5, name=Billie, age=24, email=test5@baomidou.com]
2020-07-01 15:49:58.791  INFO 15452 --- [extShutdownHook] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
2020-07-01 15:49:58.796  INFO 15452 --- [extShutdownHook] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.
2020-07-01 15:49:58.797  INFO 15452 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'

13.完整的pom.xml文件

<?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>2.3.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>springboot-mybatis-plus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-mybatis-plus</name>
    <description>Mybatis Plus 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.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.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.2</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

14.参考

MyBatis-Plus 的官方快速开始文档
MyBatis-Plus 的官方示例工程