使用 Spring Initializr 快速初始化一个 Spring Boot 工程
Group:com.atguigu
Artifact:mybatis-plus
版本:2.2.1.RELEASE
1、引入依赖
spring-boot-starter、spring-boot-starter-test
添加:mybatis-plus-boot-starter、MySQL、lombok、
在项目中使用Lombok可以减少很多重复代码的书写。比如说getter/setter/toString等方法的编写
<?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>2.3.0.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.mybatisplus</groupId> <artifactId>myplus</artifactId> <version>0.0.1-SNAPSHOT</version> <name>myplus</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</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <!--mybatis-plus--> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.0.5</version> </dependency> <!--mysql--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!-- https://mvnrepository.com/artifact/io.springfox/springfox-swagger2 --> <dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger2</artifactId> <version>2.9.2</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>
四、配置在 application.properties 配置文件中添加 MySQL 数据库的相关配置:
mysql5
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driverspring.datasource.url=jdbc:mysql://localhost:3306/loadtest?serverTimezone=GMT%2B8spring.datasource.username=rootspring.datasource.password=123456#thymelea模板配置spring.thymeleaf.prefix=classpath:/templates/spring.thymeleaf.suffix=.htmlspring.thymeleaf.mode=HTML5spring.thymeleaf.encoding=UTF-8spring.thymeleaf.servlet.content-type=text/html#热部署文件,页面不产生缓存,及时更新# 开发阶段务必关闭缓存 (=false)spring.thymeleaf.cache=falsespring.resources.chain.strategy.content.enabled=truespring.resources.chain.strategy.content.paths=/**#logging.level.com.dy.springboot.server.mapper=debugspring.jackson.date-format=yyyy-MM-dd HH:mm:ssspring.jackson.time-zone=GMT+8spring.servlet.multipart.max-file-size=100MBspring.servlet.multipart.max-request-size=1000MBserver.port=8081#mybatis日志mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
注意:
1、这里的 url 使用了 ?serverTimezone=GMT%2B8 后缀,因为Spring Boot 2.1 集成了 8.0版本的jdbc驱动,这个版本的 jdbc 驱动需要添加这个后缀,否则运行测试用例报告如下错误:
java.sql.SQLException: The server time zone value 'Öйú±ê׼ʱ¼ä' is unrecognized or represents more
2、这里的 driver-class-name 使用了 com.mysql.cj.jdbc.Driver ,在 jdbc 8 中 建议使用这个驱动,之前的 com.mysql.jdbc.Driver 已经被废弃,否则运行测试用例的时候会有 WARN 信息
五、编写代码1、主类
在 Spring Boot 启动类中添加 @MapperScan 注解,扫描 Mapper 文件夹
注意:扫描的包名根据实际情况修改
import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;/** * * @author liwen406 * @date 2020-05-27 11:22 */@MapperScan("com.mybatisplus.mapper")@SpringBootApplicationpublic class MyplusApplication { public static void main(String[] args) { SpringApplication.run(MyplusApplication.class, args); }}
2、实体
创建包 entity 编写实体类 ProjectInterface.java(此处使用了 Lombok 简化代码)
import com.baomidou.mybatisplus.annotation.IdType;import com.baomidou.mybatisplus.annotation.TableId;import io.swagger.annotations.ApiModel;import io.swagger.annotations.ApiModelProperty;import lombok.Data;import lombok.EqualsAndHashCode;import lombok.experimental.Accessors;import java.io.Serializable;import java.util.Date;/** * <p> * 工程接口 * </p> * * @author liwen * @since 2020-05-25 */@Data@EqualsAndHashCode(callSuper = false)@Accessors(chain = true)@ApiModel(value = "ProjectInterface对象", description = "工程接口")public class ProjectInterface implements Serializable { private static final long serialVersionUID = 1L; @ApiModelProperty(value = "主键ID") @TableId(value = "id", type = IdType.AUTO) private Long id; @ApiModelProperty(value = "工程id") private Long projectId; private String interName; @ApiModelProperty(value = "接口url")
Lombok使用参考:
https://blog.csdn.net/motui/article/details/79012846
3、mapper
创建包 mapper 编写Mapper 接口: ProjectInterfaceMapper.java
import com.baomidou.mybatisplus.core.mapper.BaseMapper;import com.mybatisplus.pojo.ProjectInterface;import org.springframework.stereotype.Repository;/** * @author liwen * @Title: ProjectInterfaceMapper * @Description: * @date 2020/5/27 / 11:33 * IDEA在 userMapper 处报错,因为找不到注入的对象,因为类是动态创建的,但是程序可以正确的执行。 * <p> * 为了避免报错,可以在 dao 层 的接口上添加 @Repository 注 */@Repositorypublic interface ProjectInterfaceMapper extends BaseMapper<ProjectInterface> {}
六、开始使用添加测试类,进行功能测试:
import com.mybatisplus.mapper.ProjectInterfaceMapper;import com.mybatisplus.pojo.ProjectInterface;import org.junit.jupiter.api.Test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.context.SpringBootTest;import java.util.List;@SpringBootTestclass MyplusApplicationTests { @Autowired ProjectInterfaceMapper projectInterfaceMapper; @Test void contextLoads() { System.out.println(("----- selectAll method test ------")); List<ProjectInterface> projectInterfaces = projectInterfaceMapper.selectList(null); projectInterfaces.forEach(System.out::println); }}