相信不少朋友在項目中使用的ORM框架都是MyBatis,若是單用MyBatis來操做數據庫的話,須要手寫不少單表查詢的SQL實現。這時候咱們每每會選擇一個加強工具來實現這些單表CRUD操做,這裏推薦一款好用的工具MyBatis-Plus!php
MyBatis-Plus(簡稱 MP)是一個 MyBatis 的加強工具,在 MyBatis 的基礎上只作加強不作改變,爲簡化開發、提升效率而生。MyBatis-Plus 提供了代碼生成器,能夠一鍵生成controller、service、mapper、model、mapper.xml代碼,同時提供了豐富的CRUD操做方法,助咱們解放雙手!前端
首先咱們須要在SpringBoot項目中集成MyBatis-Plus,以後咱們再詳細介紹它的使用方法!java
在pom.xml中添加相關依賴,主要是MyBatis-Plus、MyBatis-Plus Generator和Velocity模板引擎;mysql
<dependencies>
<!--Mybatis-Plus依賴-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.3.2</version>
</dependency>
<!--Mybatis-Plus代碼生成器-->
<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添加以下配置,配置好數據源和MyBatis-Plus;spring
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路徑
global-config:
db-config:
id-type: auto #全局默認主鍵類型設置爲自增
configuration:
auto-mapping-behavior: partial #只對非嵌套的 resultMap 進行自動映射
map-underscore-to-camel-case: true #開啓自動駝峯命名規則映射
添加MyBatis-Plus的Java配置,使用@MapperScan註解配置好須要掃碼的Mapper接口路徑,MyBatis-Plus自帶分頁功能,須要配置好分頁插件PaginationInterceptor。sql
/**
* MyBatis配置類
* 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;
}}
MyBatis-Plus 提供了代碼生成器,能夠一鍵生成controller、service、mapper、model、mapper.xml代碼,很是方便!typescript
首先咱們建立代碼生成器類MyBatisPlusGenerator,直接運行其main方法便可生成相關代碼;數據庫
/**
* MyBatisPlus代碼生成器 * 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("模塊名");
String[] tableNames = scanner("表名,多個英文逗號分割").split(",");
// 代碼生成器 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();
} /** * 讀取控制檯內容信息 */ private static String scanner(String tip) { Scanner scanner = new Scanner(System.in);
System.out.println(("請輸入" + tip + ":"));
if (scanner.hasNext()) {
String next = scanner.next();
if (StrUtil.isNotEmpty(next)) {
return next;
} } throw new MybatisPlusException("請輸入正確的" + 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;
} /** * 初始化數據源配置 */ 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(); //能夠對controller、service、entity模板進行配置 //mapper.xml模板需單獨配置 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);
//當表名中帶*號時能夠啓用通配符模式 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;
} /** * 初始化自定義配置 */ private static InjectionConfig initInjectionConfig(String projectPath, String moduleName) { // 自定義配置 InjectionConfig injectionConfig = new InjectionConfig() { @Override public void initMap() { // 可用於自定義屬性 } }; // 模板引擎是Velocity String templatePath = "/templates/mapper.xml.vm";
// 自定義輸出配置 List<FileOutConfig> focList = new ArrayList<>(); // 自定義配置會被優先輸出 focList.add(new FileOutConfig(templatePath) { @Override public String outputFile(TableInfo tableInfo) { // 自定義輸出文件名 , 若是你 Entity 設置了先後綴、此處注意 xml 的名稱會跟着發生變化!! return projectPath + "/src/main/resources/mapper/" + moduleName
+ "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
} }); injectionConfig.setFileOutConfigList(focList); return injectionConfig;
}}
而後在resources目錄下添加配置文件generator.properties,添加代碼生成器的數據源配置及存放業務代碼的基礎包名稱;apache
dataSource.url=jdbc:mysql://localhost:3306/mall?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
dataSource.driverName=com.mysql.cj.jdbc.DriverdataSource.username=rootdataSource.password=rootpackage.base=com.macro.mall.tiny.modules
細心的朋友能夠發現MyBatisPlusGenerator中不少配置代碼都沒添加註釋,其實MyBatis-Plus源碼中的中文註釋很是完善,只需查看源碼便可,這裏摘抄一段DataSourceConfig中的源碼;mybatis
/**
* 數據庫配置
*
* @author YangHu, hcl
* @since 2016/8/30
*/
@Data
@Accessors(chain = true)
public class DataSourceConfig {
/**
* 數據庫信息查詢
*/
private IDbQuery dbQuery;
/**
* 數據庫類型
*/
private DbType dbType;
/**
* PostgreSQL schemaName
*/
private String schemaName;
/**
* 類型轉換
*/
private ITypeConvert typeConvert;
/**
* 關鍵字處理器
* @since 3.3.2
*/
private IKeyWordsHandler keyWordsHandler;
/**
* 驅動鏈接的URL
*/
private String url;
/**
* 驅動名稱
*/
private String driverName;
/**
* 數據庫鏈接用戶名
*/
private String username;
/**
* 數據庫鏈接密碼
*/
private String password;
//省略若干代碼......
}
代碼生成器支持兩種模式,一種生成單表的代碼,好比只生成pms_brand表代碼能夠先輸入pms,後輸入pms_brand;
生成單表代碼結構一覽;
另外一種直接生成整個模塊的代碼,須要帶通配符*,好比生成ums模塊代碼能夠先輸入ums,後輸入ums_*;
生成整個模塊代碼結構一覽。
MyBatis-Plus 使用模板引擎來生成代碼,支持 Velocity(默認)、Freemarker、Beetl模板引擎,這裏以Velocity爲了來介紹下如何自定義生成模板。
首先咱們能夠從 MyBatis-Plus Generator依賴包的源碼中找到默認模板,拷貝到項目的resources/templates目錄下;
在MyBatisPlusGenerator類中對TemplateConfig進行配置,配置好各個模板的路徑;
/**
* MyBatisPlus代碼生成器
* 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();
//能夠對controller、service、entity模板進行配置
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模板需單獨配置
templateConfig.setXml(null);
return templateConfig;
}
}
對模板進行定製,在定製過程當中咱們能夠發現不少內置變量,用於輸出到模板中去,這裏以service.java.vm模板爲例子,好比package、table這些變量;
package ${package.Service};
import ${package.Entity}.${entity};
import ${superServiceClassPackage};
/** * <p> * $!{table.comment} 服務類 * </p> * * @author ${author}
* @since ${date}
*/#if(${kotlin})
interface ${table.serviceName} : ${superServiceClass}<${entity}>
#elsepublic interface ${table.serviceName} extends ${superServiceClass}<${entity}> {
}#end
搞懂這些變量從哪來的,對咱們定製模板頗有幫助,其實這些變量都來着於AbstractTemplateEngine的getObjectMap方法,具體變量做用能夠參考源碼。
/**
* 模板引擎抽象類 * * @author hubin * @since 2018-01-10
*/public abstract class AbstractTemplateEngine { /** * 渲染對象 MAP 信息 * * @param tableInfo 表信息對象 * @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);
}}
MyBatis-Plus的強大之處不止在於它的代碼生成功能,還在於它提供了豐富的CRUD方法,讓咱們實現單表CRUD幾乎不用手寫SQL實現!
咱們以前生成的PmsBrandMapper接口因爲繼承了BaseMapper接口,直接擁有了各類CRUD方法;
/**
* <p>
* 品牌表 Mapper 接口
* </p>
*
* @author macro
* @since 2020-08-20
*/
public interface PmsBrandMapper extends BaseMapper<PmsBrand> {
}
咱們來看下BaseMapper中的方法,是否是基本能夠知足咱們的平常所需了;
咱們以前生成的PmsBrandService接口因爲繼承了IService接口,也擁有了各類CRUD方法;
/**
* <p>
* 品牌表 服務類
* </p>
*
* @author macro
* @since 2020-08-20
*/
public interface PmsBrandService extends IService<PmsBrand> {
}
能夠看下比BaseMapper中的更加豐富;
有了這些IService和BaseMapper中提供的這些方法,咱們單表查詢就幾乎不用手寫SQL實現了,使用MyBatis-Plus實現之前PmsBrandController的方法更輕鬆了!
/**
* <p>
* 品牌表 前端控制器
* </p>
*
* @author macro
* @since 2020-08-20
*/
@Api(tags = "PmsBrandController", description = "商品品牌管理")
@RestController
@RequestMapping("/brand")
public class PmsBrandController {
private static final Logger LOGGER = LoggerFactory.getLogger(PmsBrandController.class);
@Autowired
private PmsBrandService brandService;
@ApiOperation("獲取全部品牌列表")
@RequestMapping(value = "/listAll", method = RequestMethod.GET)
@ResponseBody
public CommonResult<List<PmsBrand>> getBrandList() {
return CommonResult.success(brandService.list());
} @ApiOperation("添加品牌")
@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("操做失敗");
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("操做失敗");
LOGGER.debug("updateBrand failed:{}", pmsBrand);
} return commonResult;
} @ApiOperation("刪除指定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("操做失敗");
} } @ApiOperation("分頁查詢品牌列表")
@RequestMapping(value = "/list", method = RequestMethod.GET)
@ResponseBody
public CommonResult<CommonPage<PmsBrand>> listBrand(@RequestParam(value = "pageNum", defaultValue = "1")
@ApiParam("頁碼") Integer pageNum,
@RequestParam(value = "pageSize", defaultValue = "3")
@ApiParam("每頁數量") Integer pageSize) {
Page<PmsBrand> page = new Page<>(pageNum, pageSize); Page<PmsBrand> pageResult = brandService.page(page); return CommonResult.success(CommonPage.restPage(pageResult));
} @ApiOperation("獲取指定id的品牌詳情")
@RequestMapping(value = "/{id}", method = RequestMethod.GET)
@ResponseBody
public CommonResult<PmsBrand> brand(@PathVariable("id") Long id) {
return CommonResult.success(brandService.getById(id)); }}