【SpringBoot框架篇】14.mybatis-plus实战

╰+攻爆jí腚メ 2023-02-23 07:46 38阅读 0赞

### 文章目录 ###

*  简介
 *  版本
 *  使用模板生成器生成模板代码
 *   *  添加依赖
     *  创建表
     *  创建模板实体类的超类
     *  添加模板生成器代码
     *  运行main函数
 *  使用mybatis-plus实现基本的CRUD功能
 *   *  通用代码层
     *   *  service代码详解
         *  mapper
     *  控制器层调用接口
     *  自定义分页条件注入器
     *  页面查询条件注入代码
     *  配套代码已上传到github上
 *  项目配套代码

# 简介 #

Mybatis-Plus（简称MP）是一个 Mybatis 的增强工具，在 Mybatis 的基础上只做增强不做改变，为简化开发、提高效率而生。这是官方给的定义，关于mybatis-plus的更多介绍及特性，可以参考mybatis-plus官网。那么它是怎么增强的呢？其实就是它已经封装好了一些crud方法，我们不需要再写xml了，直接调用这些方法就行，就类似于JPA。

官网地址: [https://mybatis.plus/guide/][https_mybatis.plus_guide]

# 版本 #

*  springboot版本是: 2.3.0.RELEASE
 *  mybatis-plus-boot-starter的使用的 3.3.2

# 使用模板生成器生成模板代码 #

## 添加依赖 ##

<properties>
            <java.version>1.8</java.version>
            <mybatis-plus.version>3.3.2</mybatis-plus.version>
        </properties>
        
         <dependencies> 
           
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>${mybatis-plus.version}</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-generator</artifactId>
                <version>${mybatis-plus.version}</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-freemarker</artifactId>
            </dependency>
            
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </dependency>
       
        </dependencies>

## 创建表 ##

CREATE TABLE sys_user (
    id int  AUTO_INCREMENT,
    username varchar(20) COMMENT '用户名',
    password varchar(20) COMMENT '密码',
    create_time datetime COMMENT '创建时间',
    grade   int COMMENT '年纪',
     PRIMARY KEY (id)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

## 创建模板实体类的超类 ##

通常会把一些通用的字段放入到超类中

@Data
    public class BaseEntity { 
    
        private Integer id;
    
        @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
        private Date createTime;
    
    }

## 添加模板生成器代码 ##

public class MysqlGenerator { 
    
        //生成类的作者描述
        private final static String AUTHOR="LeeJunMing";
        private final static String DATASOURCE_URL="jdbc:mysql://localhost:3306/boot_master?useSSL=false&serverTimezone=GMT%2b8&characterEncoding=utf8&connectTimeout=10000&socketTimeout=3000&autoReconnect=true";
        private final static String DATASOURCE_DRIVER_NAME="com.mysql.cj.jdbc.Driver";
        private final static String DATASOURCE_USERNAME="root";
        private final static String DATASOURCE_PASSWORD="123456";
        //基础包名
        private final static String BASE_PACKAGE="com.ljm.boot";
        //生成的模块名称
        private final static String MODEL_NAME="mybatisplus";
        //超类的字段(不会出现在自动生成的表中)
        private final static String[] SUERP_COLUMN=new String[]{ "id","create_time"};
        //要把哪些表生成模板代码
        private final static String [] GENERATOR_TABLES=new String[]{ "sys_user"};
    
        public static void main(String[] args) { 
            // 代码生成器
            AutoGenerator mpg = new AutoGenerator();
    
            // 全局配置
            GlobalConfig gc = new GlobalConfig();
            String projectPath = System.getProperty("user.dir");
            //聚合工程需要写工程的名字,普通工程写 '' 就行
            String parantPath="/14_mybatis-plus";
            gc.setOutputDir(projectPath + parantPath+"/src/main/java");
            gc.setAuthor(AUTHOR);
            gc.setOpen(false);
            mpg.setGlobalConfig(gc);
    
            // 数据源配置
            DataSourceConfig dsc = new DataSourceConfig();
            dsc.setUrl(DATASOURCE_URL);
            dsc.setDriverName(DATASOURCE_DRIVER_NAME);
            dsc.setUsername(DATASOURCE_USERNAME);
            dsc.setPassword(DATASOURCE_PASSWORD);
            mpg.setDataSource(dsc);
    
            // 包配置
            PackageConfig pc = new PackageConfig();
            pc.setModuleName(MODEL_NAME);
            pc.setParent(BASE_PACKAGE);
            mpg.setPackageInfo(pc);
    
            // 自定义配置
            InjectionConfig cfg = new InjectionConfig() { 
                @Override
                public void initMap() { 
                    // to do nothing
                }
            };
            List<FileOutConfig> focList = new ArrayList<>();
            focList.add(new FileOutConfig("/templates/mapper.xml.ftl") { 
                @Override
                public String outputFile(TableInfo tableInfo) { 
                    // 自定义输入文件名称
                    return projectPath + parantPath+"/src/main/java/"+BASE_PACKAGE.replaceAll("\\.","/")+"/" + pc.getModuleName()
                            + "/mapper/xml/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
                }
            });
            cfg.setFileOutConfigList(focList);
            mpg.setCfg(cfg);
            mpg.setTemplate(new TemplateConfig().setXml(null));
    
            // 策略配置
            StrategyConfig strategy = new StrategyConfig();
            strategy.setNaming(NamingStrategy.underline_to_camel);
            strategy.setColumnNaming(NamingStrategy.underline_to_camel);
            strategy.setEntityLombokModel(true);
    
            //设置控制器的超类
            //strategy.setSuperControllerClass("com.baomidou.mybatisplus.samples.generator.common.BaseController");
    
            //设置实体类的超类
            strategy.setSuperEntityClass(BaseEntity.class);
            //设置
            strategy.setInclude(GENERATOR_TABLES);
            strategy.setSuperEntityColumns(SUERP_COLUMN);
            strategy.setControllerMappingHyphenStyle(true);
            mpg.setStrategy(strategy);
    
            // 选择 freemarker 引擎需要指定如下加，注意 pom 依赖必须有！
            mpg.setTemplateEngine(new FreemarkerTemplateEngine());
            mpg.execute();
        }
    
    }

## 运行main函数 ##

看到下面的日志就代表模板文件生成成功了.  
![在这里插入图片描述][20200705221900535.png]  
会把每个表生成一个controller->service->mapper>xml>entity  
生成的结构如下  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pbmcxOTk1MTIyNA_size_16_color_FFFFFF_t_70]

# 使用mybatis-plus实现基本的CRUD功能 #

## 通用代码层 ##

下面的代码会在模板生成器生成模板的时候会自动添加上

### service代码详解 ###

此处继承了ServiceImpl通用代码实现类

@Service
    public class SysUserServiceImpl extends ServiceImpl<SysUserMapper, SysUser> implements ISysUserService { 
    
    }

查看ServiceImpl 源码能看到已经定义了一些通用的代码

//新增 这个有点迷,我以为会和Jpa一样自动判断添加和修改,这个save只能添加
    boolean save(T entity);
    
    //根据id获取
    T getById(Serializable id)
    
    //根据条件查询
    List<T> list(Wrapper<T> queryWrapper)
    
    //分页查询
    <E extends IPage<T>> E page(E page, Wrapper<T> queryWrapper);
    
    //批量新增 (默认是1000条,可以调用saveBatch(Collection<T> entityList, int batchSize)指定批量操作数量)
    boolean saveBatch(Collection<T> entityList)
    
    //添加或者修改
    boolean saveOrUpdate(T entity);
    
    //批量添加或者修改
    boolean saveOrUpdateBatch(Collection<T> entityList)
    
    //根据ID删除
    removeById(Serializable id)
    
    //根据Id批量删除
    boolean removeByIds(Collection<? extends Serializable> idList)

### mapper ###

此处继承BaseMappe 接口

public interface SysUserMapper extends BaseMapper<SysUser> { 
    
    }

## 控制器层调用接口 ##

接口采用了RESTful风格

@Controller
    @RequestMapping("/user")
    public class SysUserController { 
    
        @Autowired
        ISysUserService userService;
    
        /** * 分页查询 */
        @GetMapping("/")
        public String getUserBypage(PageParam<SysUser> pageParam, Model model) { 
            pageParam.initialization();
            IPage<SysUser> iPage = userService.page(pageParam.getPage(), pageParam.getQueryWrapper());
            System.out.printf("总页数:{%d},总记录数:{%d}", iPage.getPages(), iPage.getTotal());
            model.addAttribute("page", new PageResult<>(iPage));
            return "user/index";
        }
    
        /** * ajax 分页查询 */
        @PostMapping(value = "/json")
        @ResponseBody
        public PageResult getUserJsonDataBypage(@RequestBody PageParam<SysUser> pageParam, Model model) { 
            pageParam.initialization();
            IPage<SysUser> iPage = userService.page(pageParam.getPage(), pageParam.getQueryWrapper());
            model.addAttribute("page", new PageResult<>(iPage));
            return new PageResult<>(iPage);
        }
    
    
        /** * 根据id获取user,并且跳转到数据修改页面 */
        @GetMapping("/{id}")
        public String getUserById(@PathVariable Integer id, Model model) { 
            //id=-1的时候代表着是重添加用户按钮进来的请求
            if (id != -1) { 
                SysUser user = userService.getById(id);
                model.addAttribute("user", user);
            }
            return "user/save";
        }
    
    
        /** * 添加用户 */
        @PostMapping("/")
        @ResponseBody
        public boolean addUser(SysUser user) { 
            return userService.save(user);
        }
    
        /** * 修改用户 */
        @PutMapping("/")
        @ResponseBody
        public boolean modifyUser(SysUser user) { 
            return userService.saveOrUpdate(user);
        }
    
        /** * 删除 */
        @DeleteMapping("/{ids}")
        @ResponseBody
        public boolean deleteUserById(@PathVariable String ids) { 
            String idarr[] = ids.split(",");
            if (idarr.length == 1) { 
                return  userService.removeById(idarr[0]);
            } else { 
                return userService.removeByIds(Arrays.asList(idarr));
            }
        }
    
    }

## 自定义分页条件注入器 ##

@Data
    public class PageParam<T>  { 
    
        private Integer DEFAULT_PAGE_SIZE=10;
    
        private Page<T> page;
    
        //查询条件构造器
        private QueryWrapper<T> queryWrapper;
    
        private Integer currentPage;
    
        private Integer pageSize;
    
        @JsonFormat(pattern="yyyy-MM-dd",timezone="Asia/Shanghai")
        private Date beginDate;
    
        @JsonFormat(pattern="yyyy-MM-dd",timezone="Asia/Shanghai")
        private Date endDate;
    
        private Map<String, Object> eq = new HashMap<>();
    
        private Map<String, String> like = new HashMap<>();
    
        /** * 构建jpa需要的分页对象 初始化 */
        public  void initialization() { 
            if(this.currentPage==null){ 
                this.currentPage=1;
            }
            if(this.pageSize==null){ 
                this.pageSize=this.DEFAULT_PAGE_SIZE;
            }
            this.page= new Page<>(this.currentPage, this.pageSize);
            this.setCompare();
        }
    
    
        /** * 注入查询条件参数 */
        private void setCompare() { 
            this.queryWrapper=new QueryWrapper<>();
            if (!StringUtils.isEmpty(beginDate)) { 
                //大于或等于传入时间
                queryWrapper.ge("create_time",beginDate);
            }
            if (!StringUtils.isEmpty(endDate)) { 
                //小于或等于传入时间
                queryWrapper.le("create_time",beginDate);
            }
    
            String value = "";
            //注入文本框的模糊查询参数
            for (Map.Entry<String, String> entry : like.entrySet()) { 
                value = entry.getValue().trim();
                if (StringUtils.isEmpty(value)) { 
                    continue;
                }
                //过滤掉非法的符号,不然会影响模糊查询
                value = value.replaceAll("%", "%").replaceAll("_", "_");
                queryWrapper.like(entry.getKey(),  value );
            }
    
            //注入下拉框或单选框的等值查询参数
            for (Map.Entry<String, Object> entry : eq.entrySet()) { 
                if (StringUtils.isEmpty(entry.getValue())) { 
                    continue;
                }
                queryWrapper.eq(entry.getKey(),entry.getValue());
            }
        }
    }

## 页面查询条件注入代码 ##

util.getFromData=function(form) { 
        var root={ }
        var like={ };
        var eq={ };
    
        //注入页码和当前页
        root["currentPage"]=$("[name='currentPage']").val();
        root["pageSize"]=$("[name='pageSize']").val();
    
        //文本框都用模糊查询
        form.find("[type='text']").each(function(){ 
            var value= $(this).val();      //input 值
            var name= $(this).attr('name');
            if(name.indexOf("Date")!=-1){ 
                //日期字段用root注入
                root[name]=value;
            }else{ 
                //其它文本字段注入到like参数中
                like[name]=value;
            }
        });
    
        //单选框 等值匹配
        form.find("[type='radio']:checked").each(function(){ 
            var value= $(this).val();      //input 值
            var name= $(this).attr('name');
            eq[name]=value;
        });
    
        //等值匹配
        form.find("select").each(function(){ 
            var value= $(this).val();
            var name= $(this).attr('name');
            //页码信息是用select装的,所有排除掉
            if(name!="pageSize"){ 
                eq[name]=value;
            }
        });
    
        root['eq']=eq;
        root['like']=like;
        return root;
    }
    
    var $form=$("form");
    $.ajax({ 
            type: 'post',
            url: url,
            data: JSON.stringify(util.getFromData($form)),
            contentType: "application/json",
            success: function (page){ 
            
    		}, 
            error:function () { 
                layer.msg("网络异常!", { icon: 2, time: 2000});
            }
        });

## 配套代码已上传到github上 ##

github地址: [https://github.com/Dominick-Li/springboot-master][https_github.com_Dominick-Li_springboot-master]

该demo已经实现了简单的CRUD+分页查询功能  
由于生成模板需要用的freemarker模板引擎,所以页面的数据渲染也使用的freemarker模板引擎渲染  
页面的ui库使用的h-ui,官网地址:[http://www.h-ui.net/][http_www.h-ui.net]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pbmcxOTk1MTIyNA_size_16_color_FFFFFF_t_70 1]

# 项目配套代码 #

[github地址][https_github.com_Dominick-Li_springboot-master]

创作不易,要是觉得我写的对你有点帮助的话,麻烦在github上帮我点下 **Star**

【SpringBoot框架篇】其它文章如下,后续会继续更新。

*  [1.搭建第一个springboot项目][1._springboot]
 *  [2.Thymeleaf模板引擎实战][2.Thymeleaf]
 *  [3.优化代码,让代码更简洁高效][3.]
 *  [4.集成jta-atomikos实现分布式事务][4._jta-atomikos]
 *  [5.分布式锁的实现方式][5.]
 *  [6.docker部署,并挂载配置文件到宿主机上面][6.docker]
 *  [7.项目发布到生产环境][7.]
 *  [8.搭建自己的spring-boot-starter][8._spring-boot-starter]
 *  [9.dubbo入门实战][9.dubbo]
 *  [10.API接口限流实战][10.API]
 *  [11.Spring Data Jpa实战][11.Spring Data Jpa]
 *  [12.使用druid的monitor工具查看sql执行性能][12._druid_monitor_sql]
 *  [13.使用springboot admin对springboot应用进行监控][13._springboot admin_springboot]
 *  [14.mybatis-plus实战][14.mybatis-plus]
 *  [15.使用shiro对web应用进行权限认证][15._shiro_web]
 *  [16.security整合jwt实现对前后端分离的项目进行权限认证][16.security_jwt]
 *  [17.使用swagger2生成RESTful风格的接口文档][17._swagger2_RESTful]
 *  [18.使用Netty加websocket实现在线聊天功能][18._Netty_websocket]
 *  [19.使用spring-session加redis来实现session共享][19._spring-session_redis_session]
 *  [20.自定义@Configuration配置类启用开关][20._Configuration]
 *  [21.对springboot框架编译后的jar文件瘦身][21._springboot_jar]
 *  [22.集成RocketMQ实现消息发布和订阅][22._RocketMQ]

[https_mybatis.plus_guide]: https://mybatis.plus/guide/
[20200705221900535.png]: https://img-blog.csdnimg.cn/20200705221900535.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pbmcxOTk1MTIyNA_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200705221711177.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pbmcxOTk1MTIyNA==,size_16,color_FFFFFF,t_70
[https_github.com_Dominick-Li_springboot-master]: https://github.com/Dominick-Li/springboot-master
[http_www.h-ui.net]: http://www.h-ui.net/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pbmcxOTk1MTIyNA_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200705225723808.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pbmcxOTk1MTIyNA==,size_16,color_FFFFFF,t_70
[1._springboot]: https://blog.csdn.net/ming19951224/article/details/106159309
[2.Thymeleaf]: https://blog.csdn.net/ming19951224/article/details/106160322
[3.]: https://blog.csdn.net/ming19951224/article/details/106173840
[4._jta-atomikos]: https://blog.csdn.net/ming19951224/article/details/105753333
[5.]: https://blog.csdn.net/ming19951224/article/details/106205332
[6.docker]: https://blog.csdn.net/ming19951224/article/details/105923548
[7.]: https://blog.csdn.net/ming19951224/article/details/106212271
[8._spring-boot-starter]: https://blog.csdn.net/ming19951224/article/details/106224172
[9.dubbo]: https://blog.csdn.net/ming19951224/article/details/106225928
[10.API]: https://blog.csdn.net/ming19951224/article/details/106227451
[11.Spring Data Jpa]: https://blog.csdn.net/ming19951224/article/details/106308544
[12._druid_monitor_sql]: https://blog.csdn.net/ming19951224/article/details/106317893
[13._springboot admin_springboot]: https://blog.csdn.net/ming19951224/article/details/107138845
[14.mybatis-plus]: https://blog.csdn.net/ming19951224/article/details/107145780
[15._shiro_web]: https://blog.csdn.net/ming19951224/article/details/107192585
[16.security_jwt]: https://blog.csdn.net/ming19951224/article/details/107733689
[17._swagger2_RESTful]: https://blog.csdn.net/ming19951224/article/details/107741541
[18._Netty_websocket]: https://blog.csdn.net/ming19951224/article/details/108555917
[19._spring-session_redis_session]: https://blog.csdn.net/ming19951224/article/details/112758560
[20._Configuration]: https://blog.csdn.net/ming19951224/article/details/112759717
[21._springboot_jar]: https://dominick-li.blog.csdn.net/article/details/119024251
[22._RocketMQ]: https://dominick-li.blog.csdn.net/article/details/119523197