1.建包和配置文件

导入依赖

 
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!--        引入mysql链接的依赖-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <!--        引入mybatis依赖-->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot</artifactId>
        <version>2.1.12.RELEASE</version>
    </dependency>
 
</dependencies>
<!--spring的maven项目必备的一个插件-->
<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>
 
 
<repositories>
    <repository>
        <id>alimaven</id>
        <name>aliyun maven</name>
        <layout>default</layout>
        <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
    </repository>
</repositories>
 
<pluginRepositories>
    <pluginRepository>
        <id>alimaven</id>
        <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
    </pluginRepository>
</pluginRepositories>

配置resource文件，新建application.properties

server.port=8082
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springcloud_course?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
spring.datasource.username=root
spring.datasource.password=20020829
logging.pattern.console=%clr(%d{${LOG_DATEFORMAT_PATTERN:HH:mm:ss.SSS}}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:%wEx}
mybatis.configuration.map-underscore-to-camel-case=true
spring.application.name=course-price

说明：

这里修改了端口，每个模块使用不同端口。。。

2.建立controller层

package com.imooc.course.controller;
 
import com.imooc.course.entity.CoursePrice;
import com.imooc.course.service.CoursePriceService;
import javax.xml.ws.Action;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
 
/**
 * 描述：     课程价格控制器
 */
@RestController
public class CoursePriceController {
 
    @Autowired
    CoursePriceService coursePriceService;
 
    @GetMapping("/price")
    public Integer getCoursePrice(Integer courseId) {
        CoursePrice coursePrice = coursePriceService.getCoursePrice(courseId);
        return coursePrice.getPrice();
    }
}

实体类

package com.imooc.course.entity;
 
import java.io.Serializable;
import javafx.beans.property.IntegerProperty;
 
/**
 * 描述：     CoursePrice的实体类
 */
public class CoursePrice implements Serializable {
 
    Integer id;
    Integer courseId;
    Integer price;
 
    @Override
    public String toString() {
        return "CoursePrice{" +
                "id=" + id +
                ", courseId=" + courseId +
                ", price=" + price +
                '}';
    }
 
    public Integer getId() {
        return id;
    }
 
    public void setId(Integer id) {
        this.id = id;
    }
 
    public Integer getCourseId() {
        return courseId;
    }
 
    public void setCourseId(Integer courseId) {
        this.courseId = courseId;
    }
 
    public Integer getPrice() {
        return price;
    }
 
    public void setPrice(Integer price) {
        this.price = price;
    }
}

2.调用service层

接口

package com.imooc.course.service;
 
import com.imooc.course.entity.CoursePrice;
 
/**
 * 描述：     课程价格服务
 */
public interface CoursePriceService {
 
    CoursePrice getCoursePrice(Integer courseId);
}

实现

package com.imooc.course.service.impl;
 
import com.imooc.course.dao.CoursePriceMapper;
import com.imooc.course.entity.CoursePrice;
import com.imooc.course.service.CoursePriceService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
/**
 * 描述：     课程价格的服务实现类
 */
@Service
public class CoursePriceServiceImpl implements CoursePriceService {
 
    @Autowired
    CoursePriceMapper coursePriceMapper;
 
    @Override
    public CoursePrice getCoursePrice(Integer courseId) {
        return coursePriceMapper.findCoursePrice(courseId);
    }
}

3.Mapper层开发

package com.imooc.course.dao;
 
import com.imooc.course.entity.CoursePrice;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;
 
/**
 * 描述：     课程价格Mapper类
 */
@Mapper
@Repository
public interface CoursePriceMapper {
 
    @Select("SELECT * FROM course_price WHERE course_id = #{courseId}")
    CoursePrice findCoursePrice(Integer courseId);
}

4.主启动类

package com.imooc.course;
 
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
public class CoursePriceApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(CoursePriceApplication.class, args);
    }