前后端分离开发的后端代码简单案例

1.pom依赖

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

<!-- 数据库连接 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
<!-- mybatis-plus启动器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.0</version>
        </dependency>
        <!-- 代码生成器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-engine-core</artifactId>
            <version>2.2</version>
        </dependency>

    <!-- lombok辅助工具 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

2. 代码实例

用mybatis-plus启动器生成代码，并进行了修改
对应数据库student表格

student类

@Data
@EqualsAndHashCode(callSuper = false)
//@ApiModel(value="Student对象", description="")
public class Student implements Serializable {

    private static final long serialVersionUID = 1L;

    private String name;

    private String sSex;


}

mapper

public interface StudentMapper extends BaseMapper<Student> {

}

IStudentService

public interface IStudentService extends IService<Student> {

}

StudentServiceImpl

@Service
public class StudentServiceImpl extends ServiceImpl<StudentMapper, Student> implements IStudentService {

}

自定义返回数据的类R

//用于返回数据的封装
@Data
public class R {
    private Integer code;
    private Boolean status;
    private Map<String,Object> data =new HashMap<>();
    private String message;


    //私有构造方法
    private R(){}

    //链式编程
    public static R ok(){
        R r = new R();
        r.setStatus(true);
        r.setCode(200);
        return  r;
    }
    public static R error(String message,Integer code){
        R r =new R();
        r.setStatus(false);
        r.setCode(code);
        r.setMessage(message);
        return r;
    }

    //数据封装
    public R put(String key,Object value){
        this.data.put(key,value);
        return this;
    }


}

controller

@RestController
@RequestMapping("/stu/student")
public class StudentController {

    @Autowired
    private IStudentService studentService;

    //RestFul风格
    @GetMapping
    public R list(){
        return  R.ok().put("data",studentService.list());
    }

}

application.properties

# 微服务命名
spring.application.name=stu-service
#端口声明
server.port=8090


#数据库配置
spring.datasource.url=jdbc:mysql://localhost:3306/temporary?useUnicode=true&useSSL=false&characterEncoding=utf8
spring.datasource.username=root
spring.datasource.password=12345
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

显示结果：