Spring Boot整合Mybatis Plus和Swagger2的教程详解

<?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>2.4.3</version>
 <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>study</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>study</name>
<description>Demo project for Spring Boot</description>

<properties>
 <!--依赖的版本-->
 <java.version>1.8</java.version>
 <mysql.version>8.0.13</mysql.version>
 <mybatisPlus.version>3.4.1</mybatisPlus.version>
 <druid.version>1.0.9</druid.version>
 <swagger.version>2.9.2</swagger.version>
 <hutool.version>5.5.8</hutool.version>
</properties>

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

 <!--mysql-->
 <dependency>
 <groupId>mysql</groupId>
 <artifactId>mysql-connector-java</artifactId>
 <scope>runtime</scope>
 <version>${mysql.version}</version>
 </dependency>

 <!-- MyBatis-Plus-->
 <dependency>
 <groupId>com.baomidou</groupId>
 <artifactId>mybatis-plus-boot-starter</artifactId>
 <version>${mybatisPlus.version}</version>
 </dependency>
 <dependency>
 <groupId>com.baomidou</groupId>
 <artifactId>mybatis-plus-generator</artifactId>
 <version>${mybatisPlus.version}</version>
 </dependency>

 <!--druid-->
 <dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>druid</artifactId>
 <version>${druid.version}</version>
 </dependency>

 <!--swagger2-->
 <dependency>
 <groupId>io.springfox</groupId>
 <artifactId>springfox-swagger2</artifactId>
 <version>${swagger.version}</version>
 </dependency>
 <dependency>
 <groupId>io.springfox</groupId>
 <artifactId>springfox-swagger-ui</artifactId>
 <version>${swagger.version}</version>
 </dependency>

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

# 配置端口
server:
 port: 8080

#----------------druid数据源配置-----------------------
spring:
 datasource:
 type: com.alibaba.druid.pool.DruidDataSource
 druid:
 #这里跟pom里面mysql-connector版本相关8.0之后用com.mysql.cj.jdbc.Driver，之前用com.mysql.jdbc.Driver
 driver-class-name: com.mysql.cj.jdbc.Driver
 #这里改成你自己的数据库名称以及账号和密码
 url: jdbc:mysql://127.0.0.1:3306/study?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true
 username: root
 password: 123456
 initialSize: 10
 minIdle: 10
 maxActive: 30
 # 配置获取连接等待超时的时间
 maxWait: 60000
 # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
 timeBetweenEvictionRunsMillis: 60000
 # 配置一个连接在池中最小生存的时间，单位是毫秒
 minEvictableIdleTimeMillis: 300000
 validationQuery: SELECT 1 FROM DUAL
 testWhileIdle: true
 testOnBorrow: false
 testOnReturn: false
 # 打开PSCache，并且指定每个连接上PSCache的大小
 poolPreparedStatements: true
 # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
 #filters: stat,wall,log4j
 # 通过connectProperties属性来打开mergeSql功能；慢SQL记录
 connection-properties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
 # 合并多个DruidDataSource的监控数据
 useGlobalDataSourceStat: true

#----------------mybatis plus配置-----------------------
mybatis-plus:
 # xml扫描，多个目录用逗号或者分号分隔(告诉 Mapper 所对应的 XML 文件位置)
 mapper-locations: classpath:mapper/*.xml
 configuration:
 # 是否开启自动驼峰命名规则映射:从数据库列名到Java属性驼峰命名的类似映射
 map-underscore-to-camel-case: true
 # 如果查询结果中包含空值的列，则 MyBatis 在映射的时候，不会映射这个字段
 call-setters-on-nulls: true
 # 这个配置会将执行的sql打印出来，在开发或测试的时候可以用
 log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
 # 实体扫描，多个package用逗号或者分号分隔（这里更改为你的实体类存放路径）
 typeAliasesPackage: com.example.study.model.entity
 global-config:
 db-config:
 #主键类型 AUTO:"数据库ID自增" INPUT:"用户输入ID",ID_WORKER:"全局唯一ID (数字类型唯一ID)", UUID:"全局唯一ID UUID";
 id-type: auto
 #字段策略 IGNORED:"忽略判断" NOT_NULL:"非 NULL 判断") NOT_EMPTY:"非空判断"
 field-strategy: NOT_EMPTY
 #数据库类型
 db-type: MYSQL
 # 逻辑删除配置
 # 删除前
 logic-not-delete-value: 1
 # 删除后
 logic-delete-value: 0

#----------------swagger配置-----------------------
swagger:
 #生产环境改为false（改为false后swagger-ui.html则无法访问）
 enable: true
#解决Swagger2 异常 NumberFormatException:For input string:""
logging:
 level:
 io:
 swagger:
 models:
  parameters:
  AbstractSerializableParameter: ERROR

package com.example.study.config;

import io.swagger.annotations.Api;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.ApiKey;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

import java.util.ArrayList;
import java.util.List;

/**
 * Swagger配置类
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */
@Configuration
@EnableSwagger2
@ConditionalOnProperty(name = "swagger.enable", havingValue = "true")
public class SwaggerConfig {
 /**
 * 创建API应用
 * apiInfo() 增加API相关信息
 * 通过select()函数返回一个ApiSelectorBuilder实例,用来控制哪些接口暴露给Swagger来展现，
 * 本例采用指定扫描的包路径来定义指定要建立API的目录。
 *
 * @return
 */
 @Bean
 public Docket createRestApi() {
 return new Docket(DocumentationType.SWAGGER_2)
  .apiInfo(this.apiInfo())
  .select()
  //设置选择器，选择带Api接口类的类
  .apis(RequestHandlerSelectors.withClassAnnotation(Api.class))
  //api包扫描
  .apis(RequestHandlerSelectors.basePackage("com.example.study"))
  .paths(PathSelectors.any())
  .build()
  .securitySchemes(securitySchemes());
 }

 /**
 * 创建该API的基本信息（这些基本信息会展现在文档页面中）
 * 访问地址：http://ip:端口/swagger-ui.html
 *
 * @return ApiInfo
 */
 private ApiInfo apiInfo() {
 return new ApiInfoBuilder().title("demo项目")
  .description("demo项目API文档")
  .termsOfServiceUrl("http://localhost")
  .version("1.0")
  .build();
 }

 private List<ApiKey> securitySchemes() {
 List<ApiKey> apiKeyList= new ArrayList<>();
 //apiKeyList.add(new ApiKey("token", "令牌", "header"));
 return apiKeyList;
 }
}

package com.example.study.controller;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * 首页控制器
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */
@Api(tags = "首页控制器")
@RestController
public class IndexController {

 @ApiOperation("首页html")
 @GetMapping("/")
 public String index(){
 return "hello index";
 }
}

package com.example.study.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.autoconfigure.ConfigurationCustomizer;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * 配置MybatisPlus分页插件
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */
@Configuration
@MapperScan("com.example.study.mapper")
public class MybatisPlusConfig {

 /**
 * Mybatis-plus3.4.0版本过后使用MybatisPlusInterceptor分页插件
 * 注意：DbType.MYSQL必须为自己使用的数据库类型，否则分页不生效
 */
 @Bean
 public MybatisPlusInterceptor mybatisPlusInterceptor() {
 MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
 interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
 return interceptor;
 }

 /**
 * 设置useDeprecatedExecutor = false 避免缓存出现问题
 * @return
 */
 @Bean
 public ConfigurationCustomizer configurationCustomizer() {
 return configuration -> configuration.setUseDeprecatedExecutor(false);
 }
}

CREATE TABLE `t_user` (
 `id` bigint NOT NULL AUTO_INCREMENT,
 `name` varchar(32) DEFAULT NULL,
 `age` int DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

package com.example.study.model.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

/**
 * 用户信息实体类
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */

@Data
@NoArgsConstructor
@AllArgsConstructor
@ApiModel(value = "UserEntity", description = "用户实体")
@TableName("t_user")
public class UserEntity implements Serializable {

 private static final long serialVersionUID = 6928834261563057243L;

 /**
 * 唯一标识，自增主键
 */
 @ApiModelProperty(value = "id")
 @TableId(value = "id", type = IdType.AUTO)
 private Long id;

 /**
 * 姓名
 */
 @ApiModelProperty(value = "姓名")
 @TableField("name")
 private String name;

 /**
 * 年龄
 */
 @ApiModelProperty(value = "年龄")
 @TableField("age")
 private Integer age;
}

package com.example.study.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.study.model.entity.UserEntity;

/**
 * @author 154594742@qq.com
 */
public interface UserMapper extends BaseMapper<UserEntity> {
}

package com.example.study.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.example.study.model.entity.UserEntity;

/**
 * @author 154594742@qq.com
 */
public interface UserService extends IService<UserEntity> {
}

package com.example.study.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.study.model.entity.UserEntity;
import com.example.study.mapper.UserMapper;
import com.example.study.service.UserService;
import org.springframework.stereotype.Service;

/**
 * @author 154594742@qq.com
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, UserEntity> implements UserService {
}

package com.example.study.controller;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.example.study.model.entity.UserEntity;
import com.example.study.model.param.UserParam;
import com.example.study.model.vo.ResponseVo;
import com.example.study.service.UserService;
import com.example.study.util.CommonQueryPageUtils;
import com.example.study.util.BuildResponseUtils;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

/**
 * 用户控制器
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */

@RestController
@Api(tags = "用户控制器")
public class UserController {

 @Autowired
 private UserService userService;

 @ApiOperation("新增")
 @PostMapping("user")
 public ResponseVo<?> add(UserEntity entity) {
 return userService.save(entity) ? BuildResponseUtils.success() : BuildResponseUtils.error();
 }

 @ApiOperation("通过id查询")
 @GetMapping("user/{id}")
 public ResponseVo<UserEntity> getById(@PathVariable String id) {
 return BuildResponseUtils.buildResponse(userService.getById(id));
 }

 @ApiOperation("修改")
 @PutMapping("user")
 public ResponseVo<?> update(UserEntity entity) {
 return userService.updateById(entity) ? BuildResponseUtils.success() : BuildResponseUtils.error();
 }

 @ApiOperation("通过id删除")
 @DeleteMapping("user/{id}")
 public ResponseVo<?> delete(@PathVariable String id) {
 return userService.removeById(id) ? BuildResponseUtils.success() : BuildResponseUtils.error();
 }


 @ApiOperation("分页查询")
 @GetMapping("userPage")
 public ResponseVo<IPage<UserEntity>> selectPage(UserParam param) {
 return BuildResponseUtils.buildResponse(CommonQueryPageUtils.commonQueryPage(param, userService));
 }

}

package com.example.study.enums;

/**
 * 异常类code常量（code值不要重复）
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 9:42:00
 */
public enum CodeMsgEnum {
 //请求成功
 SUCCESS("0","成功!"),
 //系统异常
 FAIL("1","失败!"),
 //以下是业务异常
 LOGIN_NO_PASS("1001","用户名或密码错误"),
 ;

 /**
 * 状态码
 */
 public String code;

 /**
 * 状态码对应信息
 */
 public String msg;

 CodeMsgEnum(String code, String msg) {
 this.code = code;
 this.msg = msg;
 }
}

package com.example.study.model.vo;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

/**
 * 统一的返回对象VO
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */

@Data
@NoArgsConstructor
@AllArgsConstructor
@ApiModel(value = "ResponseVo", description = "统一的返回对象")
public class ResponseVo<T> implements Serializable {
 private static final long serialVersionUID = 7748070653645596712L;
 /**
 * 状态码
 */
 @ApiModelProperty(value = "状态码")
 private String code;

 /**
 * 状态码对应描述信息
 */
 @ApiModelProperty(value = "状态码对应描述信息")
 private String msg;

 /**
 * 数据
 */
 @ApiModelProperty(value = "数据")
 private T data;
}

package com.example.study.constant;

/**
 * mybatis plus常用的查询方式
 * @author 154594742@qq.com
 * @date 2021/2/23 11:24
 */

public interface QueryMethodConstant {
 /**
 * 相同
 */
 String EQ = "EQ";

 /**
 * 不相同
 */
 String NE = "NE";

 /**
 * 相似，左右模糊(like '%值%')
 */
 String LIKE = "LIKE";

 /**
 * 相似，左模糊(like '%值')
 */
 String LIKE_LIFT = "LIKE_LIFT";

 /**
 * 相似，右模糊(like '值%')
 */
 String LIKE_RIGHT = "LIKE_RIGHT";

 /**
 * 不相似 (not like '%值%')
 */
 String NOT_LIKE = "NOT_LIKE";

 /**
 * 大于
 */
 String GT = "GT";

 /**
 * 大于等于
 */
 String GE = "GE";

 /**
 * 小于
 */
 String LT = "LT";

 /**
 * 小于等于
 */
 String LE = "LE";
}

package com.example.study.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 查询方式的自定义注解
 * @author 154594742@qq.com
 * @date 2021/2/23 11:24
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(value = ElementType.FIELD)
public @interface QueryMethod {

 /**
 * 字段名
 */
 String field() default "";

 /**
 * 匹配方式
 */
 String method() default "";
}

package com.example.study.util;

import com.example.study.enums.CodeMsgEnum;
import com.example.study.model.vo.ResponseVo;

/**
 * 构建返回结果工具类
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */
public final class BuildResponseUtils {

 /**
 * 构建正确请求的response
 *
 * @return ResponseVo 统一的返回结果
 */
 public static ResponseVo<?> success() {
 ResponseVo<?> response = new ResponseVo<>();
 response.setCode(CodeMsgEnum.SUCCESS.code);
 response.setMsg(CodeMsgEnum.SUCCESS.msg);
 return response;
 }

 /**
 * 构建业务异常的response
 * @param codeMsgEnum 枚举
 * @return ResponseVo 统一的返回结果
 */
 public static ResponseVo<?> success(CodeMsgEnum codeMsgEnum) {
 ResponseVo<?> response = new ResponseVo<>();
 response.setCode(codeMsgEnum.code);
 response.setMsg(codeMsgEnum.msg);
 return response;
 }

 /**
 * 构建自定义code和msg的业务异常
 *
 * @param code 自定义code
 * @param msg 自定义msg
 * @return ResponseVo 统一的返回结果
 */
 public static ResponseVo<?> success(String code, String msg) {
 ResponseVo<?> response = new ResponseVo<>();
 response.setCode(code);
 response.setMsg(msg);
 return response;
 }

 /**
 * 构建系统异常的response(只用于系统异常)
 * @return ResponseVo 统一的返回结果
 */
 public static ResponseVo<?> error() {
 ResponseVo<?> response = new ResponseVo<>();
 response.setCode(CodeMsgEnum.FAIL.code);
 response.setMsg(CodeMsgEnum.FAIL.msg);
 return response;
 }

 /**
 * 构建返回结果
 * @param obj 结果数据
 * @param <T> 结果数据的泛型
 * @return ResponseVo 统一的返回结果
 */
 public static <T> ResponseVo<T> buildResponse(T obj) {
 ResponseVo<T> response = new ResponseVo<>();
 response.setData(obj);
 response.setCode(CodeMsgEnum.SUCCESS.code);
 response.setMsg(CodeMsgEnum.SUCCESS.msg);
 return response;
 }
}

package com.example.study.util;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.metadata.OrderItem;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.IService;
import com.example.study.annotation.QueryMethod;
import com.example.study.constant.QueryMethodConstant;
import com.example.study.model.param.PageParam;

import java.lang.reflect.Field;
import java.util.Locale;

/**
 * 分页查询工具类
 *
 * @author 154594742@qq.com
 * @date: 2021/2/22 10:02:00
 */
public final class CommonQueryPageUtils {

 /**
 * 正序
 */
 private static final String ASC = "asc";

 /**
 * 倒序
 */
 private static final String DESC = "desc";

 /**
 * 通用的带排序功能的分页查询
 */
 public static <T> IPage<T> commonQueryPage(PageParam param, IService<T> service) {
 //构建page
 //根据传入的排序设置order
 //排序字段(格式：字段名:排序方式，字段名:排序方式 （asc正序，desc倒序） 示例:id:desc,age:asc)
 Page<T> page = new Page<>(param.getPage(), param.getLimit());
 String orders = param.getOrders();
 if (StringUtils.isNotBlank(orders)) {
  String[] splitArr = orders.split(",");
  for (String str : splitArr) {
  if (StringUtils.isBlank(str)) {
   continue;
  }
  String[] strArr = str.split(":");
  if (strArr.length != 2 || StringUtils.isBlank(strArr[0]) || StringUtils.isBlank(strArr[1])) {
   continue;
  }
  if (ASC.equals(strArr[1].toLowerCase(Locale.ROOT))) {
   page.addOrder(OrderItem.asc(strArr[0]));
   continue;
  }
  if (DESC.equals(strArr[1].toLowerCase(Locale.ROOT))) {
   page.addOrder(OrderItem.desc(strArr[0]));
  }
  }
 }
 //根据自定义注解构建queryWrapper
 QueryWrapper<T> queryWrapper = new QueryWrapper<>();
 Class<? extends PageParam> clazz = param.getClass();
 Field[] fields = clazz.getDeclaredFields();
 for (Field field : fields) {
  //设置对象的访问权限，保证对private的属性可以访问
  field.setAccessible(true);
  QueryMethod annotation = field.getAnnotation(QueryMethod.class);
  try {
  //属性没有值则跳过
  if (null == field.get(param)) {
   continue;
  }
  //没有加@QueryMethod 默认属性名为字段名，默认匹配方式为eq
  if (null == annotation) {
   queryWrapper.eq(field.getName(), field.get(param));
   continue;
  }

  switch (annotation.method()) {
   case QueryMethodConstant.EQ:
   queryWrapper.eq(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.NE:
   queryWrapper.ne(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.LIKE:
   queryWrapper.like(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.LIKE_LIFT:
   queryWrapper.likeLeft(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.LIKE_RIGHT:
   queryWrapper.likeRight(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.GT:
   queryWrapper.gt(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.GE:
   queryWrapper.ge(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.LT:
   queryWrapper.lt(annotation.field(), field.get(param));
   break;
   case QueryMethodConstant.LE:
   queryWrapper.le(annotation.field(), field.get(param));
   break;
   default:
   ;
  }
  } catch (IllegalAccessException e) {
  e.printStackTrace();
  }
 }
 return service.page(page, queryWrapper);
 }
}

package com.example.study.model.param;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

import java.util.LinkedHashMap;

/**
 * 统一的分页查询请求参数
 *
 * @author 154594742@qq.com
 * @date 2021/2/22 17:24
 */

@Data
@ApiModel(value = "PageParam", description = "分页参数")
public class PageParam {
 /**
 * 页码
 */
 @ApiModelProperty(value = "页码，不传则默认1")
 private Integer page = 1;

 /**
 * 每页条数
 */
 @ApiModelProperty(value = "每页条数，不传则默认10")
 private Integer limit = 10;

 /**
 * 排序字段(格式：字段名:排序方式，字段名:排序方式 （asc正序，desc倒序） 示例:id:desc,age:asc)
 */
 @ApiModelProperty(value = "排序字段(格式：字段名:排序方式，字段名:排序方式 （asc正序，desc倒序） 示例:id:desc,age:asc)")
 private String orders;
}

package com.example.study.model.param;

import com.example.study.annotation.QueryMethod;
import com.example.study.constant.QueryMethodConstant;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

/**
 * 用户查询条件类（需要根据哪些字段查询就添加哪些字段）
 * @author 154594742@qq.com
 * @date 2021/2/22 17:24
 */

@Data
@ApiModel(value = "UserParam", description = "用户查询条件")
public class UserParam extends PageParam {

 /**
 * 通过@QueryMethod注解来控制匹配的方式，这里查询条件为 name like ‘%值%'
 */
 @ApiModelProperty(value = "姓名")
 @QueryMethod(field = "name", method = QueryMethodConstant.LIKE)
 private String name;

 /**
 * 这里没有@QueryMethod注解则如果age有值，则默认查询条件为 age=值
 */
 @ApiModelProperty(value = "年龄")
 private Integer age;

 /**
 * 假如要查询 (值1 < age < 值2)则可以采用如下方式添加两个属性minAge和maxAge，
 * ‘ @QueryMethod 注解的field是数据表字段名，method是查询方式
 * 假如minAge = 18，maxAge=25，则通过CommonQueryPageUtils工具类会构建出的sql为 18<age AND age>25
 */
 @ApiModelProperty(value = "年龄下限")
 @QueryMethod(field = "age", method = QueryMethodConstant.GT)
 private String minAge;

 @ApiModelProperty(value = "年龄上限")
 @QueryMethod(field = "age", method = QueryMethodConstant.LT)
 private String maxAge;
}

insert into `t_user`(`id`,`name`,`age`) values 
(1,'小二',20),
(2,'张三',20),
(3,'李四',20),
(4,'王五',35),
(5,'小六',18);

{
 "code": "0",
 "msg": "成功!",
 "data": {
 "records": [
 {
 "id": 5,
 "name": "小六",
 "age": 18
 },
 {
 "id": 1,
 "name": "小二",
 "age": 20
 },
 {
 "id": 2,
 "name": "张三",
 "age": 20
 },
 {
 "id": 3,
 "name": "李四",
 "age": 20
 }
 ],
 "total": 4,
 "size": 10,
 "current": 1,
 "orders": [
 {
 "column": "age",
 "asc": true
 }
 ],
 "optimizeCountSql": true,
 "hitCount": false,
 "countId": null,
 "maxLimit": null,
 "searchCount": true,
 "pages": 1
 }
}