1.首先，准备阶段，用ideal创建一个springBoot的web项目，并且能够向浏览器端输出hello world，
这里我之前文章有讲述，这里就不在叙述。
2.向已准备好的web项目的pom.xml文件添加以下依赖：
mysql
mysql-connector-java
8.0.19
com.baomidou
mybatis-plus
${mybatisplus.version}
com.baomidou
mybatisplus-spring-boot-starter
${mybatisplus.spring.boot.version}
com.alibaba
druid-spring-boot-starter
${druid.version}
我个人的完整pom.xml文件如下
4.0.0
org.springframework.boot
spring-boot-starter-parent
2.2.5.RELEASE
com.tefei
isak
0.0.1-SNAPSHOT
isak
Demo project for Spring Boot
1.8
2.1.9
1.0.5
1.1.10
org.springframework.boot
spring-boot-starter-web
org.springframework.boot
spring-boot-starter-test
test
org.junit.vintage
junit-vintage-engine
mysql
mysql-connector-java
8.0.19
com.baomidou
mybatis-plus
${mybatisplus.version}
com.baomidou
mybatisplus-spring-boot-starter
${mybatisplus.spring.boot.version}
com.alibaba
druid-spring-boot-starter
${druid.version}
io.swagger
swagger-annotations
1.5.13
org.springframework.boot
spring-boot-maven-plugin
在以上依赖中，注意，我的mysql驱动依赖版本是8.0.19（因为我本地的mysql版本是8.0,我网上搜了一下对应的驱动版本，发现8.0对应的驱动版本为8.0.19,版本不一，可能还有其它对应的版本，自行对自己的本地mysql的版本添加对应的驱动即可）
3.添加完依赖后，运行项目，发现项目会报一个与url相关的错误，意思大概是你没有配置数据库连接路径，错误如下：
***************************
APPLICATION FAILED TO START
***************************
Description:
Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.
Reason: Failed to determine a suitable driver class
要解决该错误，向项目的配置文件添加以下代码即可：
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.cj.jdbc.Driver
druid:
url: jdbc:mysql://localhost:3306/yz_server?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT
username: root
password: 1234
以上代码的url要换成自己本地的数据库连接，还有username和password要填写正确。
我个人完整的配置文件如下：
server:
port: 8081
servlet:
context-path: /isak
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.cj.jdbc.Driver
druid:
url: jdbc:mysql://localhost:3306/yz_server?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT
username: root
password: 1234
#mybatis
mybatis-plus:
mapper-locations: classpath:mapper/**/*.xml
#实体扫描，多个package用逗号或者分号分隔
typeAliasesPackage: com.tefei.*.entity
global-config:
#主键类型 0:"数据库ID自增", 1:"用户输入ID",2:"全局唯一ID (数字类型唯一ID)", 3:"全局唯一ID UUID";
id-type: 0
#字段策略 0:"忽略判断",1:"非 NULL 判断"),2:"非空判断"
field-strategy: 1
#驼峰下划线转换
db-column-underline: true
#刷新mapper 调试神器
refresh-mapper: true
#数据库大写下划线转换
#capital-mode: true
# Sequence序列接口实现类配置
#key-generator: com.baomidou.mybatisplus.incrementer.OracleKeyGenerator
#逻辑删除配置
logic-delete-value: -1
logic-not-delete-value: 0
#自定义填充策略接口实现
#meta-object-handler: com.baomidou.springboot.xxx
#自定义SQL注入器
sql-injector: com.baomidou.mybatisplus.mapper.LogicSqlInjector
configuration:
map-underscore-to-camel-case: true
cache-enabled: false
call-setters-on-nulls: true
# log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
在以上配置都准备完后(项目能够正常运行)，就可以开始编写dao、entity、service、mapper和controller了。
个人entity层代码如下：
package com.tefei.isak.entity;
import com.baomidou.mybatisplus.annotations.TableField;
import com.baomidou.mybatisplus.annotations.TableId;
import com.baomidou.mybatisplus.annotations.TableName;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import java.io.Serializable;
import java.util.Date;
/**
* @author isak
* @date 2020-03-14 20:16
*/
@TableName("user_detail")
@ApiModel(value = "用户对象")
public class UserDetailEntity implements Serializable {
private static final long serialVersionUID = 1L;
/**
*
*/
@TableId
private Long id;
/**
*
*/
private String openid;
/**
*
*/
@ApiModelProperty(value = "用户头像")
private String headimg;
/**
*
*/
@ApiModelProperty(value = "用户昵称")
private String name;
/**
* 性别
*/
private boolean gender;
/**
*
*/
private String city;
/**
*
*/
private String province;
private String region;
/**
*
*/
private String address;
/**
*
*/
private String remark;
private String userCode;
/**
*
*/
private String lgpoint;
private String phone;
private String trueName;
@ApiModelProperty(value = "个人介绍")
private String introduce;
/**
*
*/
private Date createTime;
/**
*
*/
private Date updateTime;
@TableField(exist = false)
private long countOrder;
@TableField(exist = false)
private Double sumEarnings;
private boolean isVip;
@TableField(exist = false)
private Long inviteCount;
private Long level;
/**
* 设置：
*/
public void setId(Long id) {
this.id = id;
}
/**
* 获取：
*/
public Long getId() {
return id;
}
/**
* 设置：
*/
public void setOpenid(String openid) {
this.openid = openid;
}
/**
* 获取：
*/
public String getOpenid() {
return openid;
}
/**
* 设置：
*/
public void setHeadimg(String headimg) {
this.headimg = headimg;
}
/**
* 获取：
*/
public String getHeadimg() {
return headimg;
}
/**
* 设置：
*/
public void setName(String name) {
this.name = name;
}
/**
* 获取：
*/
public String getName() {
return name;
}
/**
* 设置：
*/
public void setAddress(String address) {
this.address = address;
}
/**
* 获取：
*/
public String getAddress() {
return address;
}
/**
* 设置：
*/
public void setRemark(String remark) {
this.remark = remark;
}
/**
* 获取：
*/
public String getRemark() {
return remark;
}
/**
* 设置：
*/
public void setCreateTime(Date createTime) {
this.createTime = createTime;
}
/**
* 获取：
*/
public Date getCreateTime() {
return createTime;
}
/**
* 设置：
*/
public void setUpdateTime(Date updateTime) {
this.updateTime = updateTime;
}
/**
* 获取：
*/
public Date getUpdateTime() {
return updateTime;
}
public String getUserCode() {
return userCode;
}
public void setUserCode(String userCode) {
this.userCode = userCode;
}
public String getLgpoint() {
return lgpoint;
}
public void setLgpoint(String lgpoint) {
this.lgpoint = lgpoint;
}
public boolean isGender() {
return gender;
}
public void setGender(boolean gender) {
this.gender = gender;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getProvince() {
return province;
}
public void setProvince(String province) {
this.province = province;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getTrueName() {
return trueName;
}
public void setTrueName(String trueName) {
this.trueName = trueName;
}
public long getCountOrder() {
return countOrder;
}
public void setCountOrder(long countOrder) {
this.countOrder = countOrder;
}
public Double getSumEarnings() {
return sumEarnings;
}
public void setSumEarnings(Double sumEarnings) {
this.sumEarnings = sumEarnings;
}
public boolean isVip() {
return isVip;
}
public void setVip(boolean vip) {
isVip = vip;
}
public Long getInviteCount() {
return inviteCount;
}
public void setInviteCount(Long inviteCount) {
this.inviteCount = inviteCount;
}
public String getRegion() {
return region;
}
public void setRegion(String region) {
this.region = region;
}
public String getIntroduce() {
return introduce;
}
public void setIntroduce(String introduce) {
this.introduce = introduce;
}
public Long getLevel() {
return level;
}
public void setLevel(Long level) {
this.level = level;
}
}
以上实体的属性和本地数据库里面的user_detail表的字段相对应。
然后是：dao层代码如下：
package com.tefei.isak.dao;
import com.baomidou.mybatisplus.mapper.BaseMapper;
import com.tefei.isak.entity.UserDetailEntity;
/**
* @author isak
* @date 2020-03-14 20:16
*/
public interface UserDetailDao extends BaseMapper {
}
该层代码比较简单，只要继承了mybatisplus的BaseMapper即可。
再然后，是书写mapper,如下：
编写mapper的时候要注意：namespace和type必须对应上面的dao和entity,另外，如果自己书写了sql查询语句的话，resultType也必须和指定entity对应。
接下来就是service和controller了
关于service和serviceImp的代码如下：
package com.tefei.isak.service;
import com.baomidou.mybatisplus.service.IService;
import com.tefei.isak.entity.UserDetailEntity;
/**
* @author isak
* @date 2020-03-14 20:16
*/
public interface UserDetailService extends IService {
}
package com.tefei.isak.service.serviceImp;
import com.baomidou.mybatisplus.service.impl.ServiceImpl;
import com.tefei.isak.dao.UserDetailDao;
import com.tefei.isak.entity.UserDetailEntity;
import com.tefei.isak.service.UserDetailService;
import org.springframework.stereotype.Service;
@Service("userDetailService")
public class UserDetailServiceImpl extends ServiceImpl implements UserDetailService {
}
最后，再编写一个controller来调用service的服务就好了，这里说明一下，mybats plus 已经为我们封装好了基本的CRUD了，我们可以直接进行基本的增删改查啦。
controller层代码如下：
package com.tefei.isak.controller;
import com.tefei.isak.common.R;
import com.tefei.isak.entity.UserDetailEntity;
import com.tefei.isak.service.UserDetailService;
import io.swagger.annotations.Api;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
/**
* @author isak
* @date 2020-03-14 20:16
*/
@RestController
@RequestMapping("userdetail")
@Api(tags = "用户接口")
public class UserDetailController {
@Autowired
private UserDetailService userDetailService;
@RequestMapping("/info/{id}")
public R queryById(@PathVariable("id") Long id){
UserDetailEntity userDetailEntity = userDetailService.selectById(id);
if(userDetailEntity!=null){
return R.ok().put("userDetailEntity",userDetailEntity);
}else{
return R.error("查詢错误");
}
}
}
上面的selectById方法就是mybatis plus为我们封装好的方法（通过主键id查询数据）。
还有就是这个controller层的R对象你可能有不理解的地方。其实这个R对象就是对这个方法的返回数据进行封装，先看返回的数据效果吧，我用postman对controller的接口进行请求，效果如下：
1.PNG
返回的数据格式：
{
"msg": "success",
"code": 0,
"userDetailEntity": {
"id": 13,
"openid": "oI1hhw07KPweExgvGo9f713GOzgc",
"headimg": "http://thirdwx.qlogo.cn/mmopen/vi_32/Q0j4TwGTfTLxxZWshOd9XZBjRYnwgLTjAkmHnDyJN08RA2OIG4qicd5DScXdsyzfFb0QCLQhktK0ug791ryEjUg/132",
"name": "Xiongfan",
"gender": true,
"city": "九江",
"province": "江西",
"region": null,
"address": null,
"remark": null,
"userCode": "10013",
"lgpoint": null,
"phone": null,
"trueName": "Xiongfan",
"introduce": null,
"createTime": "2019-12-06T12:05:15.000+0000",
"updateTime": "2019-12-06T12:05:15.000+0000",
"countOrder": 0,
"sumEarnings": null,
"inviteCount": null,
"level": 1,
"vip": false
}
}
如果你不熟悉这个R对象的话，我们对controller进行改进：改进的代码如下（修改方法返回对象）
package com.tefei.isak.controller;
import com.tefei.isak.common.R;
import com.tefei.isak.entity.UserDetailEntity;
import com.tefei.isak.service.UserDetailService;
import io.swagger.annotations.Api;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
/**
* @author isak
* @date 2020-03-14 20:16
*/
@RestController
@RequestMapping("userdetail")
@Api(tags = "用户接口")
public class UserDetailController {
@Autowired
private UserDetailService userDetailService;
@RequestMapping("/info/{id}")
public UserDetailEntity queryById(@PathVariable("id") Long id){
UserDetailEntity userDetailEntity = userDetailService.selectById(id);
if(userDetailEntity!=null){
return userDetailEntity;
}else{
return null;
}
}
}
然后再用postman进行模拟，效果如下：
1.PNG
返回的数据格式
{
"id": 13,
"openid": "oI1hhw07KPweExgvGo9f713GOzgc",
"headimg": "http://thirdwx.qlogo.cn/mmopen/vi_32/Q0j4TwGTfTLxxZWshOd9XZBjRYnwgLTjAkmHnDyJN08RA2OIG4qicd5DScXdsyzfFb0QCLQhktK0ug791ryEjUg/132",
"name": "Xiongfan",
"gender": true,
"city": "九江",
"province": "江西",
"region": null,
"address": null,
"remark": null,
"userCode": "10013",
"lgpoint": null,
"phone": null,
"trueName": "Xiongfan",
"introduce": null,
"createTime": "2019-12-06T12:05:15.000+0000",
"updateTime": "2019-12-06T12:05:15.000+0000",
"countOrder": 0,
"sumEarnings": null,
"inviteCount": null,
"level": 1,
"vip": false
}
由此可见，关于这个R对象，只是把请求的数据以不同形式进行返回。
自此，一个关于springBoot的web项目简单整合mybatis plus就完毕啦。
补充：
所查询的数据在数据库中如下图所示：
1.PNG
ps:加上俺的项目目录结构截图，方便理解
1.PNG
（天啦撸，这个整合我弄了好几次，一直失败，这次终于成功了，赶紧写个总结一下，万一哪天忘了 = _ =）
每天进步一点点，学习很重要，但感觉总结更重要啊！！！