Springboot入门之整合mybatis

1，创建maven工程，在pom.xml中添加jar包依赖。

<?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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.travelsky.springboot</groupId>
    <artifactId>03-springboot-mybatis</artifactId>
    <version>1.0.0</version>    
    <!--继承springboot父级项目的依赖-->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <!--属性配置-->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!--springboot开发web项目的起步依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--加载mybatis整合springboot-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <!--MySQL的jdbc驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <!--配置mybatis自动生成器插件-->
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.6</version>
                <configuration>
                    <!--配置文件的位置-->
                    <configurationFile>GeneratorMapper.xml</configurationFile>
                    <verbose>true</verbose>
                    <overwrite>true</overwrite>
                </configuration>
            </plugin>

        </plugins>

    </build>
</project>

2，创建数据库springbootmb，创建表student

3，创建application.properties文件，指定mapper.xml文件的路径和数据源信息。

#指定mapper.xml文件的路径
mybatis.mapper-locations=classpath:com/travelsky/springboot/mapper/*.xml

########################################################
###datasource -- 指定mysql数据库连接信息.
########################################################
spring.datasource.url = jdbc:mysql://localhost:3306/springboot
spring.datasource.username = root
spring.datasource.password = root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

4，将mybatis自动生成器GeneratorMapper.xml放入工程中

<?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>

    <!--指定连接数据库的JDBC驱动包所在位置，指定到你本机的完整路径 
    需要确保本地maven仓库中是否含有此数据库驱动jar包-->
    <classPathEntry location="E:/repository/mysql/mysql-connector-java/5.1.41/mysql-connector-java-5.1.41.jar"/>

    <!--配置table表信息内容体，targetRuntime指定采用mybatis3的版本-->
    <context id="tables" targetRuntime="MyBatis3">
        <!--抑制生成注释，由于生成的注释都是英文的，可以不让它生成-->
        <commentGenerator>
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>

        <!--配置数据库连接信息 每次需手动修改数据库名和用户名密码-->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/springbootmb"
                        userId="root"
                        password="root">
        </jdbcConnection>

        <!--生成model类，targetPackage指定model类的包名，targetProject指定生成的model放在工程下面那个位置-->
        <javaModelGenerator targetPackage="com.travelsky.springboot.model" targetProject="src/main/java">
            <property name="enableSubPackages" value="false"/>
            <property name="trimStrings" value="false"/>
        </javaModelGenerator>
        <!--生成mapper类，targetPackage指定mapper类的包名，targetProject指定生成的mapper放在工程下面那个位置-->
        <sqlMapGenerator targetPackage="com.travelsky.springboot.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="false"/>

        </sqlMapGenerator>
        <!--生成Mybatis的Mapper.xml文件，targetPackage指定mapper类的包名,targetProject指定生成的mapper.xml放在eclipse哪个工程下面-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.travelsky.springboot.mapper"
                             targetProject="src/main/java">
            <property name="enableSubpackages" value="false"/>
        </javaClientGenerator>

        <!--数据库表名以及对应的java模型类名 
        tableName：数据库中表名 domainObjectName：生成的实体类名-->
        <table tableName="student"
               domainObjectName="Student"
               enableUpdateByExample="false"
               enableDeleteByExample="false"
               enableSelectByExample="false"
               selectByExampleQueryId="false"/>
    </context>


</generatorConfiguration>

5，自动生成model和mapper

在IDEA的Maven Project中刷新一下可以看到mybatis-generator，双击下面的mybatis-gennerator:generate

可以看到控制台BUILD SUCCESS

此时工程下生成了model和mapper

此时算是真正准备好了springboot与mybatis整合的开发环境

6，创建springboot的main方法 application.java，启动springboot程序

加上@SpringBootApplication注解开启自动扫描

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

7，在生成的mapper接口文件类上加@Mapper注解，或者在运行的主类添加@MapperScan（“com.travelsky.springboot.mapper”）注解扫描

如果加上mapper注解后在接口实现类中注入mapper时候报错，这是IEDA工具报错，按照下图步骤将错误修改为警告即可

8，创建service和controller访问数据库返回json格式数据

@Service
public class StudentServiceImpl implements StudentService {
    @Autowired
    private StudentMapper studentMapper;

    @Override
    public List<Student> getAll() {
        return studentMapper.selectAll();
    }
}

@RestController
public class MyBatisController {
    @Autowired
    private StudentServiceImpl getAllStudentServiceImpl;

    @ResponseBody
    @RequestMapping("boot/getAll")
    public Object getAllStudent(){
        //调用service
        List<Student> list = getAllStudentServiceImpl.getAll();
        return list;
    }
}

访问结果：