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置信很多敌人在我的项目中应用的 ORM 框架都是 MyBatis,如果单用 MyBatis 来操作数据库的话,须要手写很多单表查问的 SQL 实现。这时候咱们往往会抉择一个加强工具来实现这些单表 CRUD 操作,这里举荐一款好用的工具 MyBatis-Plus!
SpringBoot 实战电商我的项目 mall(40k+star)地址:https://github.com/macrozheng/mall
MyBatis-Plus 简介
MyBatis-Plus(简称 MP)是一个 MyBatis 的加强工具,在 MyBatis 的根底上只做加强不做扭转,为简化开发、提高效率而生。MyBatis-Plus 提供了代码生成器,能够一键生成 controller、service、mapper、model、mapper.xml 代码,同时提供了丰盛的 CRUD 操作方法,助咱们解放双手!
MyBatis-Plus 集成
首先咱们须要在 SpringBoot 我的项目中集成 MyBatis-Plus,之后咱们再具体介绍它的应用办法!
- 在
pom.xml
中增加相干依赖,次要是 MyBatis-Plus、MyBatis-Plus Generator 和 Velocity 模板引擎;
<dependencies>
<!--Mybatis-Plus 依赖 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.3.2</version>
</dependency>
<!--Mybatis-Plus 代码生成器 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-generator</artifactId>
<version>3.3.2</version>
</dependency>
<!--Velocity 模板生成引擎 -->
<dependency>
<groupId>org.apache.velocity</groupId>
<artifactId>velocity-engine-core</artifactId>
<version>2.2</version>
</dependency>
</dependencies>
- 在 SpringBoot 配置文件
application.yml
增加如下配置,配置好数据源和 MyBatis-Plus;
spring:
datasource:
url: jdbc:mysql://localhost:3306/mall?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
username: root
password: root
mybatis-plus:
mapper-locations: classpath:/mapper/**/*.xml #指定 mapper.xml 门路
global-config:
db-config:
id-type: auto #全局默认主键类型设置为自增
configuration:
auto-mapping-behavior: partial #只对非嵌套的 resultMap 进行主动映射
map-underscore-to-camel-case: true #开启主动驼峰命名规定映射
- 增加 MyBatis-Plus 的 Java 配置,应用
@MapperScan
注解配置好须要扫码的 Mapper 接口门路,MyBatis-Plus 自带分页性能,须要配置好分页插件PaginationInterceptor
。
/**
* MyBatis 配置类
* Created by macro on 2019/4/8.
*/
@Configuration
@MapperScan("com.macro.mall.tiny.modules.*.mapper")
public class MyBatisConfig {
@Bean
public PaginationInterceptor paginationInterceptor() {PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
return paginationInterceptor;
}
}
代码生成器
MyBatis-Plus 提供了代码生成器,能够一键生成 controller、service、mapper、model、mapper.xml 代码,十分不便!
- 首先咱们创立代码生成器类
MyBatisPlusGenerator
,间接运行其main
办法即可生成相干代码;
/**
* MyBatisPlus 代码生成器
* Created by macro on 2020/8/20.
*/
public class MyBatisPlusGenerator {public static void main(String[] args) {String projectPath = System.getProperty("user.dir") + "/mall-tiny-plus";
String moduleName = scanner("模块名");
String[] tableNames = scanner("表名,多个英文逗号宰割").split(",");
// 代码生成器
AutoGenerator autoGenerator = new AutoGenerator();
autoGenerator.setGlobalConfig(initGlobalConfig(projectPath));
autoGenerator.setDataSource(initDataSourceConfig());
autoGenerator.setPackageInfo(initPackageConfig(moduleName));
autoGenerator.setCfg(initInjectionConfig(projectPath, moduleName));
autoGenerator.setTemplate(initTemplateConfig());
autoGenerator.setStrategy(initStrategyConfig(tableNames));
autoGenerator.setTemplateEngine(new VelocityTemplateEngine());
autoGenerator.execute();}
/**
* 读取控制台内容信息
*/
private static String scanner(String tip) {Scanner scanner = new Scanner(System.in);
System.out.println(("请输出" + tip + ":"));
if (scanner.hasNext()) {String next = scanner.next();
if (StrUtil.isNotEmpty(next)) {return next;}
}
throw new MybatisPlusException("请输出正确的" + tip + "!");
}
/**
* 初始化全局配置
*/
private static GlobalConfig initGlobalConfig(String projectPath) {GlobalConfig globalConfig = new GlobalConfig();
globalConfig.setOutputDir(projectPath + "/src/main/java");
globalConfig.setAuthor("macro");
globalConfig.setOpen(false);
globalConfig.setSwagger2(true);
globalConfig.setBaseResultMap(true);
globalConfig.setFileOverride(true);
globalConfig.setDateType(DateType.ONLY_DATE);
globalConfig.setEntityName("%s");
globalConfig.setMapperName("%sMapper");
globalConfig.setXmlName("%sMapper");
globalConfig.setServiceName("%sService");
globalConfig.setServiceImplName("%sServiceImpl");
globalConfig.setControllerName("%sController");
return globalConfig;
}
/**
* 初始化数据源配置
*/
private static DataSourceConfig initDataSourceConfig() {Props props = new Props("generator.properties");
DataSourceConfig dataSourceConfig = new DataSourceConfig();
dataSourceConfig.setUrl(props.getStr("dataSource.url"));
dataSourceConfig.setDriverName(props.getStr("dataSource.driverName"));
dataSourceConfig.setUsername(props.getStr("dataSource.username"));
dataSourceConfig.setPassword(props.getStr("dataSource.password"));
return dataSourceConfig;
}
/**
* 初始化包配置
*/
private static PackageConfig initPackageConfig(String moduleName) {Props props = new Props("generator.properties");
PackageConfig packageConfig = new PackageConfig();
packageConfig.setModuleName(moduleName);
packageConfig.setParent(props.getStr("package.base"));
packageConfig.setEntity("model");
return packageConfig;
}
/**
* 初始化模板配置
*/
private static TemplateConfig initTemplateConfig() {TemplateConfig templateConfig = new TemplateConfig();
// 能够对 controller、service、entity 模板进行配置
//mapper.xml 模板需独自配置
templateConfig.setXml(null);
return templateConfig;
}
/**
* 初始化策略配置
*/
private static StrategyConfig initStrategyConfig(String[] tableNames) {StrategyConfig strategyConfig = new StrategyConfig();
strategyConfig.setNaming(NamingStrategy.underline_to_camel);
strategyConfig.setColumnNaming(NamingStrategy.underline_to_camel);
strategyConfig.setEntityLombokModel(true);
strategyConfig.setRestControllerStyle(true);
// 当表名中带 * 号时能够启用通配符模式
if (tableNames.length == 1 && tableNames[0].contains("*")) {String[] likeStr = tableNames[0].split("_");
String likePrefix = likeStr[0] + "_";
strategyConfig.setLikeTable(new LikeTable(likePrefix));
} else {strategyConfig.setInclude(tableNames);
}
return strategyConfig;
}
/**
* 初始化自定义配置
*/
private static InjectionConfig initInjectionConfig(String projectPath, String moduleName) {
// 自定义配置
InjectionConfig injectionConfig = new InjectionConfig() {
@Override
public void initMap() {// 可用于自定义属性}
};
// 模板引擎是 Velocity
String templatePath = "/templates/mapper.xml.vm";
// 自定义输入配置
List<FileOutConfig> focList = new ArrayList<>();
// 自定义配置会被优先输入
focList.add(new FileOutConfig(templatePath) {
@Override
public String outputFile(TableInfo tableInfo) {
// 自定义输入文件名,如果你 Entity 设置了前后缀、此处留神 xml 的名称会跟着发生变化!!return projectPath + "/src/main/resources/mapper/" + moduleName
+ "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;}
});
injectionConfig.setFileOutConfigList(focList);
return injectionConfig;
}
}
- 而后在
resources
目录下增加配置文件generator.properties
,增加代码生成器的数据源配置及寄存业务代码的根底包名称;
dataSource.url=jdbc:mysql://localhost:3306/mall?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
dataSource.driverName=com.mysql.cj.jdbc.Driver
dataSource.username=root
dataSource.password=root
package.base=com.macro.mall.tiny.modules
- 仔细的敌人能够发现
MyBatisPlusGenerator
中很多配置代码都没增加正文,其实 MyBatis-Plus 源码中的中文正文十分欠缺,只需查看源码即可,这里摘抄一段DataSourceConfig
中的源码;
/**
* 数据库配置
*
* @author YangHu, hcl
* @since 2016/8/30
*/
@Data
@Accessors(chain = true)
public class DataSourceConfig {
/**
* 数据库信息查问
*/
private IDbQuery dbQuery;
/**
* 数据库类型
*/
private DbType dbType;
/**
* PostgreSQL schemaName
*/
private String schemaName;
/**
* 类型转换
*/
private ITypeConvert typeConvert;
/**
* 关键字处理器
* @since 3.3.2
*/
private IKeyWordsHandler keyWordsHandler;
/**
* 驱动连贯的 URL
*/
private String url;
/**
* 驱动名称
*/
private String driverName;
/**
* 数据库连贯用户名
*/
private String username;
/**
* 数据库连贯明码
*/
private String password;
// 省略若干代码......
}
- 代码生成器反对两种模式,一种生成单表的代码,比方只生成
pms_brand
表代码能够先输出pms
,后输出pms_brand
;
- 生成单表代码构造一览;
- 另一种间接生成整个模块的代码,须要带通配符
*
,比方生成ums
模块代码能够先输出ums
,后输出ums_*
;
- 生成整个模块代码构造一览。
自定义生成模板
MyBatis-Plus 应用模板引擎来生成代码,反对 Velocity(默认)、Freemarker、Beetl 模板引擎,这里以 Velocity 为了来介绍下如何自定义生成模板。
- 首先咱们能够从 MyBatis-Plus Generator 依赖包的源码中找到默认模板,拷贝到我的项目的
resources/templates
目录下;
- 在
MyBatisPlusGenerator
类中对TemplateConfig
进行配置,配置好各个模板的门路;
/**
* MyBatisPlus 代码生成器
* Created by macro on 2020/8/20.
*/
public class MyBatisPlusGenerator {
/**
* 初始化模板配置
*/
private static TemplateConfig initTemplateConfig() {TemplateConfig templateConfig = new TemplateConfig();
// 能够对 controller、service、entity 模板进行配置
templateConfig.setEntity("templates/entity.java");
templateConfig.setMapper("templates/mapper.java");
templateConfig.setController("templates/controller.java");
templateConfig.setService("templates/service.java");
templateConfig.setServiceImpl("templates/serviceImpl.java");
//mapper.xml 模板需独自配置
templateConfig.setXml(null);
return templateConfig;
}
}
- 对模板进行定制,在定制过程中咱们能够发现很多内置变量,用于输入到模板中去,这里以
service.java.vm
模板为例子,比方package
、table
这些变量;
package ${package.Service};
import ${package.Entity}.${entity};
import ${superServiceClassPackage};
/**
* <p>
* $!{table.comment} 服务类
* </p>
*
* @author ${author}
* @since ${date}
*/
#if(${kotlin})
interface ${table.serviceName} : ${superServiceClass}<${entity}>
#else
public interface ${table.serviceName} extends ${superServiceClass}<${entity}> {
}
#end
- 搞懂这些变量从哪来的,对咱们定制模板很有帮忙,其实这些变量都来着于
AbstractTemplateEngine
的getObjectMap
办法,具体变量作用能够参考源码。
/**
* 模板引擎抽象类
*
* @author hubin
* @since 2018-01-10
*/
public abstract class AbstractTemplateEngine {
/**
* 渲染对象 MAP 信息
*
* @param tableInfo 表信息对象
* @return ignore
*/
public Map<String, Object> getObjectMap(TableInfo tableInfo) {Map<String, Object> objectMap = new HashMap<>(30);
ConfigBuilder config = getConfigBuilder();
if (config.getStrategyConfig().isControllerMappingHyphenStyle()) {objectMap.put("controllerMappingHyphenStyle", config.getStrategyConfig().isControllerMappingHyphenStyle());
objectMap.put("controllerMappingHyphen", StringUtils.camelToHyphen(tableInfo.getEntityPath()));
}
objectMap.put("restControllerStyle", config.getStrategyConfig().isRestControllerStyle());
objectMap.put("config", config);
objectMap.put("package", config.getPackageInfo());
GlobalConfig globalConfig = config.getGlobalConfig();
objectMap.put("author", globalConfig.getAuthor());
objectMap.put("idType", globalConfig.getIdType() == null ? null : globalConfig.getIdType().toString());
objectMap.put("logicDeleteFieldName", config.getStrategyConfig().getLogicDeleteFieldName());
objectMap.put("versionFieldName", config.getStrategyConfig().getVersionFieldName());
objectMap.put("activeRecord", globalConfig.isActiveRecord());
objectMap.put("kotlin", globalConfig.isKotlin());
objectMap.put("swagger2", globalConfig.isSwagger2());
objectMap.put("date", new SimpleDateFormat("yyyy-MM-dd").format(new Date()));
objectMap.put("table", tableInfo);
objectMap.put("enableCache", globalConfig.isEnableCache());
objectMap.put("baseResultMap", globalConfig.isBaseResultMap());
objectMap.put("baseColumnList", globalConfig.isBaseColumnList());
objectMap.put("entity", tableInfo.getEntityName());
objectMap.put("entitySerialVersionUID", config.getStrategyConfig().isEntitySerialVersionUID());
objectMap.put("entityColumnConstant", config.getStrategyConfig().isEntityColumnConstant());
objectMap.put("entityBuilderModel", config.getStrategyConfig().isEntityBuilderModel());
objectMap.put("chainModel", config.getStrategyConfig().isChainModel());
objectMap.put("entityLombokModel", config.getStrategyConfig().isEntityLombokModel());
objectMap.put("entityBooleanColumnRemoveIsPrefix", config.getStrategyConfig().isEntityBooleanColumnRemoveIsPrefix());
objectMap.put("superEntityClass", getSuperClassName(config.getSuperEntityClass()));
objectMap.put("superMapperClassPackage", config.getSuperMapperClass());
objectMap.put("superMapperClass", getSuperClassName(config.getSuperMapperClass()));
objectMap.put("superServiceClassPackage", config.getSuperServiceClass());
objectMap.put("superServiceClass", getSuperClassName(config.getSuperServiceClass()));
objectMap.put("superServiceImplClassPackage", config.getSuperServiceImplClass());
objectMap.put("superServiceImplClass", getSuperClassName(config.getSuperServiceImplClass()));
objectMap.put("superControllerClassPackage", verifyClassPacket(config.getSuperControllerClass()));
objectMap.put("superControllerClass", getSuperClassName(config.getSuperControllerClass()));
return Objects.isNull(config.getInjectionConfig()) ? objectMap : config.getInjectionConfig().prepareObjectMap(objectMap);
}
}
CRUD 操作
MyBatis-Plus 的弱小之处不止在于它的代码生成性能,还在于它提供了丰盛的 CRUD 办法,让咱们实现单表 CRUD 简直不必手写 SQL 实现!
- 咱们之前生成的
PmsBrandMapper
接口因为继承了BaseMapper
接口,间接领有了各种 CRUD 办法;
/**
* <p>
* 品牌表 Mapper 接口
* </p>
*
* @author macro
* @since 2020-08-20
*/
public interface PmsBrandMapper extends BaseMapper<PmsBrand> {}
- 咱们来看下
BaseMapper
中的办法,是不是根本能够满足咱们的日常所需了;
- 咱们之前生成的
PmsBrandService
接口因为继承了IService
接口,也领有了各种 CRUD 办法;
/**
* <p>
* 品牌表 服务类
* </p>
*
* @author macro
* @since 2020-08-20
*/
public interface PmsBrandService extends IService<PmsBrand> {}
- 能够看下比
BaseMapper
中的更加丰盛;
- 有了这些
IService
和BaseMapper
中提供的这些办法,咱们单表查问就简直不必手写 SQL 实现了,应用 MyBatis-Plus 实现以前PmsBrandController
的办法更轻松了!
/**
* <p>
* 品牌表 前端控制器
* </p>
*
* @author macro
* @since 2020-08-20
*/
@Api(tags = "PmsBrandController", description = "商品品牌治理")
@RestController
@RequestMapping("/brand")
public class PmsBrandController {private static final Logger LOGGER = LoggerFactory.getLogger(PmsBrandController.class);
@Autowired
private PmsBrandService brandService;
@ApiOperation("获取所有品牌列表")
@RequestMapping(value = "/listAll", method = RequestMethod.GET)
@ResponseBody
public CommonResult<List<PmsBrand>> getBrandList() {return CommonResult.success(brandService.list());
}
@ApiOperation("增加品牌")
@RequestMapping(value = "/create", method = RequestMethod.POST)
@ResponseBody
public CommonResult createBrand(@RequestBody PmsBrand pmsBrand) {
CommonResult commonResult;
boolean result = brandService.save(pmsBrand);
if (result) {commonResult = CommonResult.success(pmsBrand);
LOGGER.debug("createBrand success:{}", pmsBrand);
} else {commonResult = CommonResult.failed("操作失败");
LOGGER.debug("createBrand failed:{}", pmsBrand);
}
return commonResult;
}
@ApiOperation("更新指定 id 品牌信息")
@RequestMapping(value = "/update", method = RequestMethod.POST)
@ResponseBody
public CommonResult updateBrand(@RequestBody PmsBrand pmsBrand) {
CommonResult commonResult;
boolean result = brandService.updateById(pmsBrand);
if (result) {commonResult = CommonResult.success(pmsBrand);
LOGGER.debug("updateBrand success:{}", pmsBrand);
} else {commonResult = CommonResult.failed("操作失败");
LOGGER.debug("updateBrand failed:{}", pmsBrand);
}
return commonResult;
}
@ApiOperation("删除指定 id 的品牌")
@RequestMapping(value = "/delete/{id}", method = RequestMethod.GET)
@ResponseBody
public CommonResult deleteBrand(@PathVariable("id") Long id) {boolean result = brandService.removeById(id);
if (result) {LOGGER.debug("deleteBrand success :id={}", id);
return CommonResult.success(null);
} else {LOGGER.debug("deleteBrand failed :id={}", id);
return CommonResult.failed("操作失败");
}
}
@ApiOperation("分页查问品牌列表")
@RequestMapping(value = "/list", method = RequestMethod.GET)
@ResponseBody
public CommonResult<CommonPage<PmsBrand>> listBrand(@RequestParam(value = "pageNum", defaultValue = "1")
@ApiParam("页码") Integer pageNum,
@RequestParam(value = "pageSize", defaultValue = "3")
@ApiParam("每页数量") Integer pageSize) {Page<PmsBrand> page = new Page<>(pageNum, pageSize);
Page<PmsBrand> pageResult = brandService.page(page);
return CommonResult.success(CommonPage.restPage(pageResult));
}
@ApiOperation("获取指定 id 的品牌详情")
@RequestMapping(value = "/{id}", method = RequestMethod.GET)
@ResponseBody
public CommonResult<PmsBrand> brand(@PathVariable("id") Long id) {return CommonResult.success(brandService.getById(id));
}
}
我的项目源码地址
https://github.com/macrozheng…
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