父pom文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <!--        <version>3.1.2</version>-->
        <version>2.2.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.chensir</groupId>
    <artifactId>springboot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot</name>
    <description>springboot</description>
    <properties>
        <java.version>8</java.version>
        <hutool.version>5.8.3</hutool.version>
        <lombok.version>1.18.24</lombok.version>
        <alibaba-sdk.version>2.0.0</alibaba-sdk.version>
    </properties>

    <packaging>pom</packaging>

    <modules>
        <module>servlet</module>
        <module>spring-interceptor</module>
        <module>spring-aop</module>
        <module>spring-united-reslut</module>
        <module>spring-jdbc</module>
        <module>spring-mybatis</module>
    </modules>

    <dependencyManagement>
        <dependencies>

           <!--钉钉机器人消息-->
            <dependency>
                <groupId>com.aliyun</groupId>
                <artifactId>alibaba-dingtalk-service-sdk</artifactId>
                <version>${alibaba-sdk.version}</version>
            </dependency>

            <dependency>
                <groupId>cn.hutool</groupId>
                <artifactId>hutool-all</artifactId>
                <version>${hutool.version}</version>
            </dependency>

            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </dependency>
<!--父pom中不要加此依赖，否则依赖clean会报错，原因是父pom中并没指定版本-->
<!--            <dependency>-->
<!--                <groupId>org.springframework.boot</groupId>-->
<!--                <artifactId>spring-boot-starter-web</artifactId>-->
<!--            </dependency>-->

<!--            <dependency>-->
<!--                <groupId>org.springframework.boot</groupId>-->
<!--                <artifactId>spring-boot-starter-test</artifactId>-->
<!--                <scope>test</scope>-->
<!--            </dependency>-->
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

pom文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.chensir</groupId>
        <artifactId>springboot</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath>
    </parent>

    <artifactId>spring-mybatis</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.1.10</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
             <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter-test</artifactId>
            <version>2.1.4</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

配置文件


spring.datasource.url=jdbc:mysql://localhost/db1?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8&autoReconnect=true&rewriteBatchedStatements=true
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

MyResponseBodyAdvice

package com.chensir.advice;

import cn.hutool.core.lang.Dict;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONUtil;
import com.github.pagehelper.Page;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import javax.servlet.http.HttpServletRequest;

// 拦截范围为 com.chensir.controller包下内容
@RestControllerAdvice(basePackages = {"com.chensir.controller"})
public class MyResponseBodyAdvice implements ResponseBodyAdvice {
    // 是否开启拦截 true开启 false不开启
    @Override
    public boolean supports(MethodParameter methodParameter, Class aClass) {
        // 此处应该改为true,否则除了异常外 走到此处为false后就直接返回,也不再继续往下走了！
        return true;
    }

    // 如果接口返回异常就在此处拦截 进行封装;value = Exception.class 对所有的异常均拦截！
    @ExceptionHandler(value = Exception.class)
    public Object defaultErrorHandler(HttpServletRequest req, Exception ex){
        ResponseDto<Object> responseDto = new ResponseDto<>();
        responseDto.setCode(501);
        responseDto.setMessage(ex.getMessage());
        return responseDto;
    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter methodParameter, MediaType mediaType, Class aClass, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
        // 有的接口再返回时会自己封装code,message,data。如果body是ResponseDto类型的实例，那么就直接返回body
//        if(body instanceof ResponseDto){
//            return body;
//        }

        ResponseDto<Object> responseDto = new ResponseDto<>();
        // 先用hutool定义为null
        String message = StrUtil.EMPTY;
        responseDto.setCode(0);
        responseDto.setMessage(message);

        if (body instanceof Page){
            Page page = (Page) body;
            int pages = page.getPages();//总页数
            long total = page.getTotal();//总条数
            Dict dict = Dict.create()
                    .set("total",total)
                    .set("pages",pages)
                    .set("item",body);
            responseDto.setData(dict);
        }else {
            responseDto.setData(body);
        }

        // 如果是string类型就用json封装一下;
        if (aClass == StringHttpMessageConverter.class) {
            return JSONUtil.toJsonStr(responseDto);
        } else {
            return responseDto;
        }

    }
}

ResponseDto<T>

package com.chensir.advice;

import lombok.Data;

import java.io.Serializable;

// 泛型
@Data
public class ResponseDto<T> implements Serializable {

    // 返回码(内部拟定)
    private int code;

    // 返回信息
    private String message;

    private T data;
}

MyBatisConfig

package com.chensir.config;

import com.github.pagehelper.PageInterceptor;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.boot.autoconfigure.ConfigurationCustomizer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.util.CollectionUtils;

import javax.sql.DataSource;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

@Configuration
@Slf4j
public class MyBatisConfig {

    @Autowired
    private ConfigurationCustomizer configurationCustomizer;
    /**
     * 自己注册SqlSessionFactory 目的是增强功能，添加分页插件
     * @param ds 代表数据源
     * @return
     * @throws Exception
     */
    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource ds) throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        // 设置数据源
        factoryBean.setDataSource(ds);

        // 把分页插件设置到SqlSessionFactory插件库
        factoryBean.setPlugins(new PageInterceptor());
        // 配置mapper.xml地址
        factoryBean.setMapperLocations(resolveMapperLocations());

        //驼峰映射注册到SqlSessionFactory中
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configurationCustomizer.customize(configuration);
        factoryBean.setConfiguration(configuration);


        // 返回具体实例对象
        SqlSessionFactory bean = factoryBean.getObject();
        return bean;
    }


    /**
     * 开启驼峰映射
     * @return
     */
    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        return new ConfigurationCustomizer() {
            @Override
            public void customize(org.apache.ibatis.session.Configuration configuration) {
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
    }

    /**
     * 查找 xxxMapper.xml
     * @return
     */
    public Resource[] resolveMapperLocations() {
        ResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
        List<String> mapperLocations = new ArrayList<>();
        mapperLocations.add("classpath*:mapper/*Mapper.xml");
//        mapperLocations.add("classpath*:com/meiwei/ping/dao/**/*Mapper.xml");
        List<Resource> resources = new ArrayList();
        if (!CollectionUtils.isEmpty(mapperLocations)) {
            for (String mapperLocation : mapperLocations) {
                try {
                    Resource[] mappers = resourceResolver.getResources(mapperLocation);
                    resources.addAll(Arrays.asList(mappers));
                } catch (IOException e) {
                    log.error("Get myBatis resources happened exception", e);
                }
            }
        }

        return resources.toArray(new Resource[resources.size()]);
    }

}

UsersController

package com.chensir.controller;

import com.chensir.entity.Users;
import com.chensir.service.UsersService;
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@RestController
public class UsersController {

    @Resource
    private UsersService usersService;

    @GetMapping("/demo1")
    public List selectUsersList(Integer pageNum,Integer pageSize) {

        // 启用分页，查询第一页，每页3条
        PageHelper.startPage(pageNum,pageSize);
        //-------------PageInfo方式---------------
//        PageInfo<Users> usersPageInfo = new PageInfo<>(usersService.selectUsersList());
//        return usersPageInfo;
        //-------------PageInfo方式---------------

        //-------------Page方式---------------
//        List<Users> users = usersService.selectUsersList();
//        Page page = (Page) users;
//        int pages = page.getPages();
//        long total = page.getTotal();
//
//
//        Map<String,Object> pageMap = new HashMap<>();
//        pageMap.put("pages",pages);
//        pageMap.put("total",total);
//        pageMap.put("items",users);
//        return pageMap;
        //-------------Page方式---------------


        //-----------使用ResponseBodyAdvice------------
        List<Users> users = usersService.selectUsersList();
        return users;
        //-----------使用ResponseBodyAdvice------------
    }

    @GetMapping("/demo2")
    public Users selectUsers(){
        Users users = usersService.selectUsers();
        return users;
    }

    @GetMapping("/demo3")
    public Map selectUsersToMap(){
        return usersService.selectUsersToMap();
    }
}

UsersMapper

@Mapper
public interface UsersMapper {

    List<Users> selectUsersList();

    Users selectUsers();

    Map<String,Object> selectUsersToMap();
}

UserMapper.xml

<?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.chensir.mapper.UsersMapper">


    <select id="selectUsersList" resultType="com.chensir.entity.Users">
        select * from users
    </select>
    <select id="selectUsers" resultType="com.chensir.entity.Users">
        select * from users where id = 1
    </select>
    <select id="selectUsersToMap" resultType="java.util.Map">
        select * from users where id = 1
    </select>
</mapper>

结果

{
  "code": 0,
  "message": "",
  "data": {
    "total": 5,
    "pages": 2,
    "item": [
      {
        "id": 1,
        "name": "chjnzkcn",
        "age": 18,
        "sex": "男",
        "tel": "123",
        "createTime": "2023-05-11",
        "updateTime": "2023-05-11"
      },
      {
        "id": 2,
        "name": "czvfzsvdv",
        "age": 20,
        "sex": "男",
        "tel": "2315",
        "createTime": "2023-05-11",
        "updateTime": "2023-05-11"
      },
      {
        "id": 3,
        "name": "sczvszv",
        "age": 18,
        "sex": "女",
        "tel": "2112321",
        "createTime": "2023-05-11",
        "updateTime": "2023-05-11"
      }
    ]
  }
}