第一步：搭建项目基本框架

新建项目及基本配置

1 IDEA新建Spring Boot项目

先从Idea上新建项目，过程选项一直下一步就可以了，路径名等请自定义。

2 搭建项目文档结构骨架

规范的项目路径便于问题的定位及项目的维护

3 添加Springboot项目基本配置文件

在application.yml中添加数据源配置和mybatis的mapper.xml的路径配置。

server:
  port: 8080

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mall?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
    username: root
    password: 123456

mybatis:
  mapper-locations:
    - classpath:mapper/*.xml
    - classpath*:com/**/mapper/*.xml

整合mybatis及mbg

1 添加依赖

为了引入mybatis及mbg等相关组件，需要添加以下依赖：mybatis、mybatis-generator、druid、mysql-connector-java。

<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatisartifactId>
    <version>3.4.6version>
dependency>

<dependency>
    <groupId>org.mybatis.generatorgroupId>
    <artifactId>mybatis-generator-coreartifactId>
    <version>1.3.7version>
dependency>

<dependency>
    <groupId>com.alibabagroupId>
    <artifactId>druid-spring-boot-starterartifactId>
    <version>1.1.10version>
dependency>

<dependency>
    <groupId>mysqlgroupId>
    <artifactId>mysql-connector-javaartifactId>
    <version>8.0.15version>
dependency>

2 添加配置文件

配置数据库连接，Mybatis生成器生成模型，mapper接口及mapper.xml路径。

<generatorConfiguration>
    <properties resource="generator.properties"/>
    <context id="MySqlContext" targetRuntime="MyBatis3" defaultModelType="flat">
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>
        <property name="javaFileEncoding" value="UTF-8"/>
        
        <plugin type="org.mybatis.generator.plugins.SerializablePlugin"/>
        
        <plugin type="org.mybatis.generator.plugins.ToStringPlugin"/>
        
        <plugin type="org.mybatis.generator.plugins.UnmergeableXmlMappersPlugin" />
        <commentGenerator type="com.hzf.mymall.mgb.CommentGenerator">
            
            <property name="suppressAllComments" value="true"/>
            <property name="suppressDate" value="true"/>
            <property name="addRemarkComments" value="true"/>
        commentGenerator>

        <jdbcConnection driverClass="${jdbc.driverClass}"
                        connectionURL="${jdbc.connectionURL}"
                        userId="${jdbc.userId}"
                        password="${jdbc.password}">
            
            <property name="nullCatalogMeansCurrent" value="true" />
        jdbcConnection>

        <javaModelGenerator targetPackage="com.hzf.mymall.model" targetProject="src\main\java"/>

        <sqlMapGenerator targetPackage="com.hzf.mymall.mapper" targetProject="src\main\resources"/>

        <javaClientGenerator type="XMLMAPPER" targetPackage="com.hzf.mymall.mapper"
                             targetProject="src\main\java"/>
        
        <table tableName="%">
            <generatedKey column="id" sqlStatement="MySql" identity="true"/>
        table>
    context>
generatorConfiguration>

3 添加Mybatis的java配置

用于配置需要动态生成的mapper接口的路径

package com.hzf.mymall.config;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Configuration;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：MyBatis配置类
 */
@Configuration
@MapperScan({"com.hzf.mymall.mapper","com.hzf.mymall.dao"})
public class MyBatisConfig {
}

4 编写MBG生成自动注释的规则

package com.hzf.mymall.mgb;

import org.mybatis.generator.api.IntrospectedColumn;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.dom.java.CompilationUnit;
import org.mybatis.generator.api.dom.java.Field;
import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
import org.mybatis.generator.internal.DefaultCommentGenerator;
import org.mybatis.generator.internal.util.StringUtility;

import java.util.Properties;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：
 */

public class CommentGenerator extends DefaultCommentGenerator {
    private boolean addRemarkComments = false;
    private static final String EXAMPLE_SUFFIX="Example";
    private static final String API_MODEL_PROPERTY_FULL_CLASS_NAME="io.swagger.annotations.ApiModelProperty";

    /**
     * 设置用户配置的参数
     */
    @Override
    public void addConfigurationProperties(Properties properties) {
        super.addConfigurationProperties(properties);
        this.addRemarkComments = StringUtility.isTrue(properties.getProperty("addRemarkComments"));
    }

    /**
     * 给字段添加注释
     */
    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable,
                                IntrospectedColumn introspectedColumn) {
        String remarks = introspectedColumn.getRemarks();
        //根据参数和备注信息判断是否添加备注信息
        if(addRemarkComments&&StringUtility.stringHasValue(remarks)){
//            addFieldJavaDoc(field, remarks);
            //数据库中特殊字符需要转义
            if(remarks.contains("\"")){
                remarks = remarks.replace("\"","'");
            }
            //给model的字段添加swagger注解
            field.addJavaDocLine("@ApiModelProperty(value = \""+remarks+"\")");
        }
    }

    /**
     * 给model的字段添加注释
     */
    private void addFieldJavaDoc(Field field, String remarks) {
        //文档注释开始
        field.addJavaDocLine("/**");
        //获取数据库字段的备注信息
        String[] remarkLines = remarks.split(System.getProperty("line.separator"));
        for(String remarkLine:remarkLines){
            field.addJavaDocLine(" * "+remarkLine);
        }
        addJavadocTag(field, false);
        field.addJavaDocLine(" */");
    }

    @Override
    public void addJavaFileComment(CompilationUnit compilationUnit) {
        super.addJavaFileComment(compilationUnit);
        //只在model中添加swagger注解类的导入
        if(!compilationUnit.isJavaInterface()&&!compilationUnit.getType().getFullyQualifiedName().contains(EXAMPLE_SUFFIX)){
            compilationUnit.addImportedType(new FullyQualifiedJavaType(API_MODEL_PROPERTY_FULL_CLASS_NAME));
        }
    }
}

5 执行Generator Main函数生成model和mapper

package com.hzf.mymall.mgb;

import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

/**
 * @author：010980380
 * @date:2020-10-21
 * @verison:1.0.0
 * @description：用于生成MBG的代码
 */

public class Generator {
    public static void main(String[] args) throws Exception {
        //MBG 执行过程中的警告信息
        List<String> warnings = new ArrayList<String>();
        //当生成的代码重复时，覆盖原代码
        boolean overwrite = true;
        //读取我们的 MBG 配置文件
        InputStream is = Generator.class.getResourceAsStream("/generatorConfig.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(is);
        is.close();

        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        //创建 MBG
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        //执行生成代码
        myBatisGenerator.generate(null);
        //输出警告信息
        for (String warning : warnings) {
            System.out.println(warning);
        }
    }
}

编写业务代码

1 添加Common类

基础的通用类包括：自定义操作码的接口、常用操作码的枚举，分页数据的封装类，通用的返回对象。

通用的返回对象

package com.hzf.mymall.common;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：通用返回对象
 */

public class CommonResult<T> {
    private long code;
    private String message;
    private T data;

    protected CommonResult(){}

    protected CommonResult(long code,String message,T data){
        this.code = code;
        this.message = message;
        this.data = data;
    }


    /**
     * 成功返回结果
     * @param data 获取的数据
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 15:43
     */
    public static <T> CommonResult<T> success(T data){
        return new CommonResult<T>(ResultCode.SUCCESS.getCode(),ResultCode.SUCCESS.getMessage(),data);
    }

    /**
     * 成功返回结果
     * @param data 获取的数据
     * @param message 提示信息
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 15:43
     */
    public static <T> CommonResult<T> success(T data,String message){
        return new CommonResult<T>(ResultCode.SUCCESS.getCode(),message,data);
    }

    /**
     * 失败返回结果
     * @param errorCode 错误码对象
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 15:49
     */
    public static <T> CommonResult<T> failed(IErrorCode errorCode){
        return new CommonResult<T>(errorCode.getCode(),errorCode.getMessage(),null);
    }
    /**
     * 失败返回结果
     * @param errorCode 错误码对象
     * @param message 提示信息
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 15:50
     */
    public static <T> CommonResult<T> failed(IErrorCode errorCode,String message){
        return new CommonResult<T>(errorCode.getCode(),message,null);
    }
    /**
     * 失败返回结果
     * @param message 提示信息
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 15:50
     */
    public static <T> CommonResult<T> failed(String message){
        return new CommonResult<T>(ResultCode.FAILED.getCode(),message,null);
    }
    /**
     * 失败返回结果
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 15:51
     */
    public static <T> CommonResult<T> failed(){
        return failed(ResultCode.FAILED);
    }

    /**
     * 参数验证失败返回结果
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 16:04
     */
    public static <T> CommonResult<T> vaildateFailed(){
        return failed(ResultCode.VALIDATE_FAILED);
    }

    /**
     * 参数验证失败返回结果
     * @param message 提示信息
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 16:05
     */
    public static <T> CommonResult<T> validateFailed(String message){
        return failed(ResultCode.VALIDATE_FAILED,message);
    }

    /**
     * 未登录返回结果
     * @param data  
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 16:04
     */
    public static <T> CommonResult<T> unauthorized(T data){
        return new CommonResult<T>(ResultCode.UNAUTHORIZED.getCode(),ResultCode.UNAUTHORIZED.getMessage(),data);
    }
    /**
     * 未授权返回结果
     * @param data
     * @return CommonResult
     * @author huangzifan
     * @since 2020-10-26 16:04
     */
    public static <T> CommonResult<T> forbidden(T data){
        return new CommonResult<T>(ResultCode.FORBIDDEN.getCode(),ResultCode.FORBIDDEN.getMessage(),data);
    }

    public long getCode() {
        return code;
    }

    public void setCode(long code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }
}

通用分页

package com.hzf.mymall.common;

import com.github.pagehelper.PageInfo;

import java.util.List;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：分页数据的封装类
 */

public class CommonPage<T> {

    private Integer pageNum;
    private Integer pageSize;
    private Integer totalpage;
    private Long total;
    private List<T> list;

    public static <T> CommonPage<T> restPage(List<T> list){
        CommonPage result =new CommonPage<T>();
        PageInfo<T> pageInfo = new PageInfo<T>(list);
        result.setPageNum(pageInfo.getPageNum());
        result.setPageSize(pageInfo.getPageSize());
        result.setTotalpage(pageInfo.getPages());
        result.setTotal(pageInfo.getTotal());
        result.setList(pageInfo.getList());
        return result;
    }

    public static <T> CommonPage<T> restPage(PageInfo<T> pageInfo){
        CommonPage result = new CommonPage<T>();

        result.setPageNum(pageInfo.getPageNum());
        result.setPageSize(pageInfo.getPageSize());
        result.setTotalpage(pageInfo.getPages());
        result.setTotal(pageInfo.getTotal());
        result.setList(pageInfo.getList());
        return result;
    }

    public Integer getPageNum() {
        return pageNum;
    }

    public void setPageNum(Integer pageNum) {
        this.pageNum = pageNum;
    }

    public Integer getPageSize() {
        return pageSize;
    }

    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }

    public Integer getTotalpage() {
        return totalpage;
    }

    public void setTotalpage(Integer totalpage) {
        this.totalpage = totalpage;
    }

    public Long getTotal() {
        return total;
    }

    public void setTotal(Long total) {
        this.total = total;
    }

    public List<T> getList() {
        return list;
    }

    public void setList(List<T> list) {
        this.list = list;
    }
}

自定义错误码接口

package com.hzf.mymall.common;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：自定义错误码接口
 */

public interface IErrorCode {
    long getCode();

    String getMessage();
}

常用操作码枚举

• SUCCESS 200
• FAILED 500
• UNAUTHORIZED 401
• FORBIDDEN 403
• VALIDATE_FAILED 404

package com.hzf.mymall.common;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：枚举常用的操作码
 */
public enum ResultCode implements IErrorCode{
    SUCCESS(200,"操作成功"),
    FAILED(500,"操作失败"),
    VALIDATE_FAILED(404,"参数检验失败"),
    UNAUTHORIZED(401,"暂未登陆或token已经过期"),
    FORBIDDEN(403,"没有相关权限");

    private long code;
    private String message;

    ResultCode(long code, String message) {
        this.code = code;
        this.message = message;
    }

    @Override
    public long getCode() {
        return code;
    }

    @Override
    public String getMessage() {
        return message;
    }
}

2 添加Service接口（PmsBrand来演示）

package com.hzf.mymall.service;

import com.hzf.mymall.model.PmsBrand;

import java.util.List;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：PmsBrand Service接口
 */

public interface PmsBrandService {

    List<PmsBrand> listAllBrand();

    int createBrand(PmsBrand brand);

    int updateBrand(Long id,PmsBrand brand);

    int deleteBrand(Long id);

    List<PmsBrand> listBrand(int pageNum,int pageSize);

    PmsBrand getBrand(Long id);

}

3 实现Service接口

package com.hzf.mymall.service.impl;

import com.github.pagehelper.PageHelper;
import com.hzf.mymall.mapper.PmsBrandMapper;
import com.hzf.mymall.model.PmsBrand;
import com.hzf.mymall.model.PmsBrandExample;
import com.hzf.mymall.service.PmsBrandService;
import org.springframework.beans.factory.annotation.Autowired;

import java.util.List;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：PmsBrand 实现类
 */

public class PmsBrandServiceImpl implements PmsBrandService {

    @Autowired
    private PmsBrandMapper brandMapper;

    @Override
    public List<PmsBrand> listAllBrand() {
        return brandMapper.selectByExample(new PmsBrandExample());
    }

    @Override
    public int createBrand(PmsBrand brand) {
        return brandMapper.insertSelective(brand);
    }

    @Override
    public int updateBrand(Long id,PmsBrand brand) {
        brand.setId(id);
        return brandMapper.updateByPrimaryKeySelective(brand);
    }

    @Override
    public int deleteBrand(Long id) {
        return brandMapper.deleteByPrimaryKey(id);
    }

    @Override
    public List<PmsBrand> listBrand(int pageNum, int pageSize) {
        PageHelper.startPage(pageNum,pageSize);
        return brandMapper.selectByExample(new PmsBrandExample());
    }

    @Override
    public PmsBrand getBrand(Long id) {
        return brandMapper.selectByPrimaryKey(id);
    }
}

4 实现Controller类

package com.hzf.mymall.controller;

import com.hzf.mymall.common.CommonPage;
import com.hzf.mymall.common.CommonResult;
import com.hzf.mymall.model.PmsBrand;
import com.hzf.mymall.service.PmsBrandService;
import org.slf4j.ILoggerFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.*;

import javax.xml.ws.RequestWrapper;
import java.util.List;

/**
 * @author：010980380
 * @date:2020-10-26
 * @verison:1.0.0
 * @description：品牌管理 Controller
 */
@Controller
@RequestMapping("/brand")
public class PmsBrandController {

    @Autowired
    private PmsBrandService demoService;

    private static final Logger LOGGER = LoggerFactory.getLogger(PmsBrandController.class);

    @RequestMapping(value = "listAll", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult<List<PmsBrand>> getBrandList(){
        return CommonResult.success(demoService.listAllBrand());
    }

    @RequestMapping(value = "/list", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult<CommonPage<PmsBrand>> listBrand(@RequestParam(value = "pageNum", defaultValue = "1") Integer pageNum,
                                                  @RequestParam(value = "pageSize", defaultValue = "3") Integer pageSize){
        List<PmsBrand> brandList = demoService.listBrand(pageNum,pageSize);
        return CommonResult.success(CommonPage.restPage(brandList));
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult<PmsBrand> Brand(@PathVariable("id") Long id){
        return CommonResult.success(demoService.getBrand(id));
    }


    @RequestMapping(value = "/create", method = RequestMethod.POST)
    @ResponseBody
    public CommonResult createBrand(@RequestBody PmsBrand pmsBrand){
        CommonResult commonResult;
        int count = demoService.createBrand(pmsBrand);
        if(count == 1){
            commonResult = CommonResult.success(pmsBrand);
            LOGGER.debug("create Brand success:{}",pmsBrand);
        }else {
            commonResult = CommonResult.failed("操作失败");
            LOGGER.debug("createBrand failed:{}",pmsBrand);
        }
        return commonResult;
    }

    @RequestMapping(value = "/update/{id}", method = RequestMethod.POST)
    @ResponseBody
    public CommonResult updateBrand(@PathVariable("id") Long id, @RequestBody PmsBrand pmsBrandDto, BindingResult result){
        CommonResult commonResult;
        int count = demoService.updateBrand(id,pmsBrandDto);
        if(count == 1){
            commonResult = CommonResult.success(pmsBrandDto);
            LOGGER.debug("updateBrand success:{}",pmsBrandDto);
        }else {
            commonResult = CommonResult.failed("操作失败");
            LOGGER.debug("updateBrand failed:{}",pmsBrandDto);
        }
        return commonResult;
    }

    @RequestMapping(value = "/delete/{id}", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult deleteBrand(@PathVariable("id") Long id){
        int count = demoService.deleteBrand(id);
        if(count == 1){
            LOGGER.debug("deleteBrand success:{}",id);
            return CommonResult.success(null);
        }else{
            LOGGER.debug("deleteBrand failed:{}",id);
            return CommonResult.failed("操作失败");
        }

    }

}

运行项目并验证