前言:如果你是初学者,请完全按照我的教程以及代码来搭建(文末会附上完整的项目代码包,你可以直接下载我提供的完整项目代码包然后自行体验!),为了照顾初学者所以贴图比较多,请耐心跟着教程来,希望这个项目Demo能给你一些帮助,如果觉得写的还可以请给个关注和点赞,谢谢!
题外话:刚开始学着用markdown来写博文,格式不好的地方请见谅
一、pom.xml和application.yml
1、pom.xml中添加相关依赖,这里我把我的pom.xml代码贴出来
<?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>
2、在resources下新建application.yml文件,并添加如下配置
# 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
3、添加druid配置类DruidConfig.java
package com.example.study.config;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
/**
* druid配置类
*
* @author 154594742@qq.com
* @date: 2021/2/22 10:02:00
*/
@Configuration
@ServletComponentScan
public class DruidConfig {
@Bean
@ConfigurationProperties(prefix = "spring.datasource.druid") //加载时读取指定的配置信息,前缀为spring.datasource.druid
public DataSource druidDataSource() {
return new DruidDataSource();
}
@Bean
public ServletRegistrationBean StatViewServlet() {
//设置druid的dashboard访问路径(ip:端口/druid/)
ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
Map<String, String> map = new HashMap<>(1);
//durid监控登录账户和密码,这里可以注释掉改为shiro或者别的方式去做访问控制
map.put("loginUsername", "admin");
map.put("loginPassword", "admin2012!");
//允许访问
map.put("allow", "");
//设置属性进注册servlet
bean.setInitParameters(map);
return bean;
}
}
二、整合Swagger2
1、添加swagger的配置类SwaggerConfig.java
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;
}
}
2、新建controller包并且在controller包下新建IndexController.java
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";
}
}
3、启动StudyApplication.java后访问 http://localhost:8080/swagger-ui.html ,出现第二图所示则表示swagger整合完成
三、整合Mybatis Plus
1、如图创建MybatisPlusConfi.java配置分页插件
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
*
* *@MapperScan注解的作用相当于在com.example.study.mapper下的所有类上面添加@Mapper注解
*
* @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);
}
}
2、在数据库中创建测试表
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
3、创建实体类UserEntity.java
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;
}
4、创建UserMapper.java
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> {
}
5、创建UserService.java
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> {
}
6、创建UserServiceImpl.java
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 {
}
7、创建UserController.java(这里编译器会提示一些错误暂时不用管,因为缺少一些类的代码)
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(一个demo用于大家学习参考)
*
* @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;
/**
* 新增
*
* @param entity 实体
* @return ResponseVo
*/
@ApiOperation("新增")
@PostMapping("user")
public ResponseVo<?> add(UserEntity entity) {
return BuildResponseUtils.buildResponse(userService.save(entity));
}
/**
* 通过id查询
*
* @param id 自增主键
* @return ResponseVo
*/
@ApiOperation("通过id查询")
@GetMapping("user/{id}")
public ResponseVo<UserEntity> getById(@PathVariable String id) {
return BuildResponseUtils.buildResponse(userService.getById(id));
}
/**
* 更新
*
* @param entity 实体
* @return ResponseVo
*/
@ApiOperation("更新")
@PutMapping("user")
public ResponseVo<?> update(UserEntity entity) {
return BuildResponseUtils.buildResponse(userService.updateById(entity));
}
/**
* 通过id删除
*
* @param id 自增主键
* @return ResponseVo
*/
@ApiOperation("通过id删除")
@DeleteMapping("user/{id}")
public ResponseVo<?> delete(@PathVariable String id) {
return BuildResponseUtils.buildResponse(userService.removeById(id));
}
/**
* 分页查询
*
* @param param 请求参数
* @return ResponseVo
*/
@ApiOperation("分页查询")
@GetMapping("userPage")
public ResponseVo<IPage<UserEntity>> selectPage(UserParam param) {
return BuildResponseUtils.buildResponse(CommonQueryPageUtils.commonQueryPage(param, userService));
}
}
8、创建枚举CodeMsgEnum.java
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;
}
}
9、创建统一的返回结果类ResponseVo.java
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;
}
10、创建常量类QueryMethodConstant.java
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";
}
11、创建自定义注解QueryMethod.java(用于后续的通用分页查询工具类)
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 "";
}
12、创建构建返回结果工具类BuildResponseUtils.java
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;
}
}
13、创建分页查询工具类CommonQueryPageUtils.java(本人自己封装的,功能可能不是很完善,但是基本的单表查询够用了)
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);
}
}
14、创建统一的分页查询请求参数类PageParam.java
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;
}
15、创建用户查询条件类UserParam.java继承PageParam(以后分页查询的参数类都要继承PageParam)
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;
}
16、先在数据库中添加几条测试数据,然后启动项目后打开 http://localhost:8080/swagger-ui.html
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);
17、按上图填入查询条件,然后点击“Execute”执行
返回的Response body:
{
"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
}
}
通过上面的返回结果可以看出我们带条件带排序的分页查询功能是ok的!新增、修改和删除没啥好说的大家可以自行体验!
感谢你看完了此篇博文,如果有什么问题可以评论留言,附上完整代码 点击下载完整代码包
后续我会在此项目代码的基础上继续整合一些技术,敬请期待!
《手把手教你Spring Boot整合Mybatis Plus 代码生成器》