编写一个springboot+mybatis分页功能

好的，以下是一个简单的示例：

1. 首先，需要在pom.xml文件中添加相关依赖：

<!-- Spring Boot Starter Web -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!-- Spring Boot Starter JDBC -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<!-- MySQL Connector Java -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

<!-- MyBatis Starter -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
</dependency>

2. 配置数据源和MyBatis：

# 数据源配置
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

# MyBatis配置
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.configuration.map-underscore-to-camel-case=true

3. 创建实体类和Mapper接口：

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

@Mapper
public interface UserMapper {
    List<User> selectAll();
}

4. 创建Mapper XML文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.example.demo.entity.User">
        <id column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="age" property="age"/>
    </resultMap>

    <select id="selectAll" resultMap="BaseResultMap">
        SELECT * FROM user
    </select>
</mapper>

5. 创建分页查询的Service和Controller：

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    public PageInfo<User> findAll(int pageNum, int pageSize) {
        PageHelper.startPage(pageNum, pageSize);
        List<User> userList = userMapper.selectAll();
        return new PageInfo<>(userList);
    }
}

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

    @Autowired
    private UserService userService;

    @GetMapping("/list")
    public PageInfo<User> findAll(@RequestParam(defaultValue = "1") int pageNum,
                                  @RequestParam(defaultValue = "10") int pageSize) {
        return userService.findAll(pageNum, pageSize);
    }
}

6. 启动应用程序并测试分页查询接口。访问 http://localhost:8080/user/list 即可查看分页查询结果。

以上就是一个简单的Spring Boot + MyBatis分页查询的示例。