写出基于spring cloud和mybatis plus，mysql的crud代码

好的，下面是一个简单的基于Spring Cloud和Mybatis Plus的CRUD代码示例，使用MySQL作为数据库：

1. 首先，需要在pom.xml文件中添加相应的依赖：

<dependencies>
    <!--Spring Cloud相关依赖-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-config</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>

    <!--Mybatis Plus相关依赖-->
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.4.3.1</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.26</version>
    </dependency>
</dependencies>

2. 在application.yml文件中配置数据库连接信息和Mybatis Plus相关配置：

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mydb?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver

mybatis-plus:
  mapper-locations: classpath:/mapper/*.xml
  type-aliases-package: com.example.demo.entity

3. 创建实体类User.java：

public class User {
    private Long id;
    private String name;
    private Integer age;
    //省略getter/setter方法
}

4. 创建Mapper接口UserMapper.java：

public interface UserMapper extends BaseMapper<User> {
}

5. 创建Service接口和实现类UserService.java：

public interface UserService {
    boolean save(User user);
    boolean deleteById(Long id);
    boolean updateById(User user);
    User getById(Long id);
    List<User> getAll();
}

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public boolean save(User user) {
        return userMapper.insert(user) > 0;
    }

    @Override
    public boolean deleteById(Long id) {
        return userMapper.deleteById(id) > 0;
    }

    @Override
    public boolean updateById(User user) {
        return userMapper.updateById(user) > 0;
    }

    @Override
    public User getById(Long id) {
        return userMapper.selectById(id);
    }

    @Override
    public List<User> getAll() {
        return userMapper.selectList(null);
    }
}

6. 创建Controller类UserController.java：

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/{id}")
    public User getById(@PathVariable Long id) {
        return userService.getById(id);
    }

    @GetMapping("/all")
    public List<User> getAll() {
        return userService.getAll();
    }

    @PostMapping("/")
    public boolean save(@RequestBody User user) {
        return userService.save(user);
    }

    @DeleteMapping("/{id}")
    public boolean deleteById(@PathVariable Long id) {
        return userService.deleteById(id);
    }

    @PutMapping("/")
    public boolean updateById(@RequestBody User user) {
        return userService.updateById(user);
    }
}

至此，一个简单的基于Spring Cloud和Mybatis Plus的CRUD示例就完成了。需要注意的是，这只是一个简单的示例，实际项目中还需要进行更多的配置和优化。