Mybatis-Plus 搭建與使用入門(小結)

Mybatis-Plus（簡稱MP）是一個Mybatis 的增強工具，在Mybatis 的基礎上只做增強不做改變，為簡化開發、提高效率而生。

中文文檔：http://baomidou.oschina.io/mybatis-plus-doc/#/

本文介紹包括

1）如何搭建
2）代碼生成（controller、service、mapper、xml）
3）單表的CRUD、條件查詢、分頁基類已經為你做好了

一、如何搭建

1. 首先我們創建一個springboot 工程--> https://start.spring.io/

2. maven 依賴

 <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>2.3</version> </dependency> <!-- velocity 依賴，用於代碼生成--> <dependency> <groupId>org.apache.velocity</groupId> <artifactId>velocity-engine-core</artifactId> <version>2.0</version> </dependency>

3. 配置（因為感覺太嗦，這裡省略了數據源的配置）

application.properties

 mybatis-plus.mapper-locations=classpath:/mapper/*Mapper.xmlmybatis-plus.typeAliasesPackage=com.taven.web.springbootmp.entitymybatis-plus.global-config.id-type=3mybatis-plus.global-config.field-strategy=2mybatis-plus.global-config.db-column-underline=truemybatis-plus.global-config.key-generator=com.baomidou.mybatisplus.incrementer.OracleKeyGeneratormybatis-plus.global-config.logic-delete-value=1mybatis-plus.global-config.logic-not-delete-value=0mybatis-plus.global-config.sql-injector=com.baomidou.mybatisplus.mapper.LogicSqlInjector#這裡需要改成你的類mybatis-plus.global-config.meta-object-handler=com.taven.web.springbootmp.MyMetaObjectHandlermybatis-plus.configuration.map-underscore-to-camel-case=truemybatis-plus.configuration.cache-enabled=falsemybatis-plus.configuration.jdbc-type-for-null=null

配置類MybatisPlusConfig

 import org.mybatis.spring.annotation.MapperScan;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import com.baomidou.mybatisplus.incrementer.H2KeyGenerator;import com.baomidou.mybatisplus.incrementer.IKeyGenerator;import com.baomidou.mybatisplus.mapper.ISqlInjector;import com.baomidou.mybatisplus.mapper.LogicSqlInjector;import com.baomidou.mybatisplus.mapper.MetaObjectHandler;import com.baomidou.mybatisplus.plugins.PaginationInterceptor;import com.baomidou.mybatisplus.plugins.PerformanceInterceptor;import com.taven.web.springbootmp.MyMetaObjectHandler;@EnableTransactionManagement@Configuration@MapperScan("com.taven.web.springbootmp.mapper")public class MybatisPlusConfig { /** * mybatis-plus SQL執行效率插件【生產環境可以關閉】 */ @Bean public PerformanceInterceptor performanceInterceptor() { return new PerformanceInterceptor(); } /* * 分頁插件，自動識別數據庫類型多租戶，請參考官網【插件擴展】 */ @Bean public PaginationInterceptor paginationInterceptor() { return new PaginationInterceptor(); } @Bean public MetaObjectHandler metaObjectHandler() { return new MyMetaObjectHandler(); } /** * 注入主鍵生成器*/ @Bean public IKeyGenerator keyGenerator() { return new H2KeyGenerator(); } /** * 注入sql注入器*/ @Bean public ISqlInjector sqlInjector() { return new LogicSqlInjector(); }}

 import com.baomidou.mybatisplus.mapper.MetaObjectHandler;import org.apache.ibatis.reflection.MetaObject;import org.slf4j.Logger;import org.slf4j.LoggerFactory;/** * 注入公共字段自動填充,任選注入方式即可*///@Componentpublic class MyMetaObjectHandler extends MetaObjectHandler { protected final static Logger logger = LoggerFactory.getLogger(Application.class); @Override public void insertFill(MetaObject metaObject) { logger.info("新增的時候干點不可描述的事情"); } @Override public void updateFill(MetaObject metaObject) { logger.info("更新的時候干點不可描述的事情"); }}

二、代碼生成

執行junit 即可生成controller、service接口及實現、mapper及xml

 import org.junit.Test;import com.baomidou.mybatisplus.generator.AutoGenerator;import com.baomidou.mybatisplus.generator.config.DataSourceConfig;import com.baomidou.mybatisplus.generator.config.GlobalConfig;import com.baomidou.mybatisplus.generator.config.PackageConfig;import com.baomidou.mybatisplus.generator.config.StrategyConfig;import com.baomidou.mybatisplus.generator.config.rules.DbType;import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;/** * <p> * 測試生成代碼* </p> * * @author K神* @date 2017/12/18 */public class GeneratorServiceEntity { @Test public void generateCode() { String packageName = "com.taven.web.springbootmp"; boolean serviceNameStartWithI = false;//user -> UserService, 設置成true: user -> IUserService generateByTables(serviceNameStartWithI, packageName, "cable", "station");//修改為你的表名} private void generateByTables(boolean serviceNameStartWithI, String packageName, String... tableNames) { GlobalConfig config = new GlobalConfig(); String dbUrl = "jdbc:mysql://localhost:3306/communicate"; DataSourceConfig dataSourceConfig = new DataSourceConfig(); dataSourceConfig.setDbType(DbType.MYSQL) .setUrl(dbUrl) .setUsername("root") .setPassword("root") .setDriverName("com.mysql.jdbc.Driver"); StrategyConfig strategyConfig = new StrategyConfig(); strategyConfig .setCapitalMode(true) .setEntityLombokModel(false) .setDbColumnUnderline(true) .setNaming(NamingStrategy.underline_to_camel) .setInclude(tableNames);//修改替換成你需要的表名，多個表名傳數組config.setActiveRecord(false) .setEnableCache(false) .setAuthor("殷天文") .setOutputDir("E://dev//stsdev//spring-boot-mp//src//main//java") .setFileOverride(true); if (!serviceNameStartWithI) { config.setServiceName("%sService"); } new AutoGenerator().setGlobalConfig(config) .setDataSource(dataSourceConfig) .setStrategy(strategyConfig) .setPackageInfo( new PackageConfig() .setParent(packageName) .setController("controller") .setEntity("entity") ).execute(); }// private void generateByTables(String packageName, String... tableNames) {// generateByTables(true, packageName, tableNames);// }}

到這一步搭建已經基本完成了，下面就可以開始使用了！

三、使用Mybatis-Plus

首先我們執行上面的generateCode() 會為我們基於表結構生成以下代碼（xml是我手動移到下面的），service 和mapper 已經繼承了基類，為我們封裝了很多方法，下面看幾個簡單的例子。

 /** * <p> * 前端控制器* </p> * * @author 殷天文* @since 2018-05-31 */@Controller@RequestMapping("/cable")public class CableController { @Autowired private CableService cableService; /** * list 查詢測試* */ @RequestMapping("/1") @ResponseBody public Object test1() { // 構造實體對應的EntityWrapper 對象，進行過濾查詢EntityWrapper<Cable> ew = new EntityWrapper<>(); ew.where("type={0}", 1) .like("name", "王") .and("core_number={0}", 24) .and("is_delete=0"); List<Cable> list = cableService.selectList(ew); List<Map<String, Object>> maps = cableService.selectMaps(ew); System.out.println(list); System.out.println(maps); return "ok"; } /** * 分頁查詢測試*/ @RequestMapping("/2") @ResponseBody public Object test2() { // 構造實體對應的EntityWrapper 對象，進行過濾查詢EntityWrapper<Cable> ew = new EntityWrapper<>(); ew.where("type={0}", 1)// .like("name", "王") .and("core_number={0}", 24) .and("is_delete=0"); Page<Cable> page = new Page<>(1,10); Page<Cable> pageRst = cableService.selectPage(page, ew); return pageRst; } /** * 自定義查詢字段*/ @RequestMapping("/3") @ResponseBody public Object test3() { Object vl = null; // 構造實體對應的EntityWrapper 對象，進行過濾查詢EntityWrapper<Cable> ew = new EntityWrapper<>(); ew.setSqlSelect("id, `name`, " + "case type/n" + "when 1 then '220kv'/n" + "end typeName") .where("type={0}", 1)// .like("name", "王") .where(false, "voltage_level=#{0}", vl);//當vl 為空時，不拼接Page<Cable> page = new Page<>(1,10); Page<Cable> pageRst = cableService.selectPage(page, ew); return pageRst; } /** * insert */ @RequestMapping("/4") @ResponseBody public Object test4() { Cable c = new Cable(); c.setName("測試光纜"); cableService.insert(c); return "ok"; } /** * update */ @RequestMapping("/5") @ResponseBody public Object test5() { Cable c = cableService.selectById(22284l); c.setName("測試光纜2222"); c.setType(1); cableService.updateById(c); return "ok"; } }

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。