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无意间发现了一个有趣的项目#xff0c;Stream-Query。了解了一下其基本的功能#xff0c;可以帮助开发者省去Mapper的编写。在开发中#xff0c;我们会编写entity和mapper来完成业务代码#xff0c;但是Stream-Query可以省去mapper#xff0c;只写entity。
快速入…前言
无意间发现了一个有趣的项目Stream-Query。了解了一下其基本的功能可以帮助开发者省去Mapper的编写。在开发中我们会编写entity和mapper来完成业务代码但是Stream-Query可以省去mapper只写entity。
快速入门
实体类
Data
public class UserInfo{private static final long serialVersionUID -7219188882388819210L;TableId(value id, type IdType.AUTO)private Long id;private String name;private Integer age;private String email;
}创表语句
create table user_info
(id bigint auto_increment comment 主键primary key,name varchar(20) null comment 姓名,age int comment 年龄,email varchar(20) comment 邮件
)comment 用户信息;配置扫描包
EnableMybatisPlusPlugin(basePackages com.charles.entity.**)插入Demo GetMapping(/t1)public void t1() {UserInfo userInfo new UserInfo();userInfo.setAge(12);userInfo.setEmail(123qq.com);userInfo.setName(张三);UserInfo userInfo2 new UserInfo();userInfo2.setAge(123);userInfo2.setEmail(123qq.com);userInfo2.setName(李四);Database.saveFewSql(Arrays.asList(userInfo, userInfo2));}单个查询Demo GetMapping(t2)public void t2() {UserInfo userInfo One.of(UserInfo::getId).eq(2L).query();System.out.println(userInfo);}多个查询Demo GetMapping(t3)public void t3() {QueryCondition.query(UserInfo.class).in(UserInfo::getName, Lists.of(张三, 李四));QueryConditionUserInfo wrapper QueryCondition.query(UserInfo.class).in(UserInfo::getName, Lists.of(张三, 李四));ListUserInfo list Database.list(wrapper);MapLong, UserInfo idUserMap OneToOne.of(UserInfo::getId).eq(1L).query();System.out.println(list);}Stream-Query通过DatabaseOneMany等静态方法完成查询和插入等操作。
核心原理分析
EnableMybatisPlusPlugin注入了StreamConfigurationSelector。
Retention(RetentionPolicy.RUNTIME)
Target({ElementType.TYPE})
Documented
Inherited
Import({StreamConfigurationSelector.class})
public interface EnableMybatisPlusPlugin {/*** Alias for {link #basePackages()}** return base packages*/String[] value() default {};/*** Base packages** return base packages*/String[] basePackages() default {};
}StreamConfigurationSelector注入了StreamScannerRegistrar扫描注册器和StreamPluginAutoConfiguration配置类。
public class StreamConfigurationSelector implements DeferredImportSelector, Ordered {Overridepublic String[] selectImports(AnnotationMetadata metadata) {return new String[] {StreamScannerRegistrar.class.getName(), StreamPluginAutoConfiguration.class.getName()};}Overridepublic int getOrder() {return HIGHEST_PRECEDENCE;}
}
StreamScannerRegistrar注入了StreamScannerConfigurer扫描类。
public class StreamScannerRegistrar implements ImportBeanDefinitionRegistrar {Overridepublic void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {AnnotationAttributes annotationAttributes AnnotationAttributes.fromMap(importingClassMetadata.getAnnotationAttributes(EnableMybatisPlusPlugin.class.getName()));if (Objects.isNull(annotationAttributes)) {return;}BeanDefinitionBuilder builder BeanDefinitionBuilder.genericBeanDefinition(StreamScannerConfigurer.class);SetString basePackages new HashSet();basePackages.addAll(Arrays.stream(annotationAttributes.getStringArray(value)).filter(StringUtils::hasText).collect(Collectors.toSet()));basePackages.addAll(Arrays.stream(annotationAttributes.getStringArray(basePackages)).filter(StringUtils::hasText).collect(Collectors.toSet()));basePackages.addAll(Arrays.stream(annotationAttributes.getClassArray(basePackageClasses)).filter(Objects::nonNull).map(ClassUtils::getPackageName).collect(Collectors.toSet()));if (basePackages.isEmpty()) {basePackages.add(ClassUtils.getPackageName(importingClassMetadata.getClassName()));builder.addPropertyValue(emptyBasePackages, true);}builder.addPropertyValue(basePackages, basePackages);SetClass? classes Arrays.stream(annotationAttributes.getClassArray(classes)).filter(Objects::nonNull).collect(Collectors.toSet());builder.addPropertyValue(classes, classes);Class? extends Annotation annotation annotationAttributes.getClass(annotation);if (!Annotation.class.equals(annotation)) {builder.addPropertyValue(annotation, annotation);}Class? scanInterface annotationAttributes.getClass(interfaceClass);if (!Class.class.equals(scanInterface)) {builder.addPropertyValue(interfaceClass, scanInterface);}registry.registerBeanDefinition(streamScannerConfigurer, builder.getBeanDefinition());}
}
StreamScannerConfigurer实现了BeanFactoryPostProcessorStreamScannerConfigurer#postProcessBeanFactory可以根据注解扫描可以根据接口扫描可以根据扫描包扫描。详情可见 enablemybatisplusplugin。 Overridepublic void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory)throws BeansException {defaultScanConfig();// 指定类registerEntityClasses(this.classes);StreamClassPathScanner scanner new StreamClassPathScanner(false);scanner.setAnnotation(this.annotation);scanner.setInterfaceClass(this.interfaceClass);scanner.registerFilters();SetClass? classSet scanner.scan(this.basePackages);registerEntityClasses(classSet);}在StreamPluginAutoConfiguration配置类中注入了DynamicMapperHandler。 BeanConditionalOnMissingBean(DynamicMapperHandler.class)public DynamicMapperHandler dynamicMapperHandler(SqlSessionFactory sqlSessionFactory, StreamScannerConfigurer streamScannerConfigurer) {return new DynamicMapperHandler(sqlSessionFactory, streamScannerConfigurer.getEntityClasses());}DynamicMapperHandler该类的作用就是根据传入的entity的列表构建Mapper。
public class DynamicMapperHandler {public DynamicMapperHandler(SqlSessionFactory sqlSessionFactory, CollectionClass? entityClassList) {Configuration configuration sqlSessionFactory.getConfiguration();if (configuration instanceof MybatisConfiguration) {MybatisConfiguration mybatisConfiguration (MybatisConfiguration) configuration;entityClassList.forEach(entityClass - Database.buildMapper(mybatisConfiguration, entityClass));}}
}Database#buildMapper根据ByteBuddy来生成对应的接口实现。 public static void buildMapper(Configuration configuration, Class? entityClass) {if (!(configuration instanceof MybatisConfiguration)) {throw new IllegalArgumentException(configuration must be MybatisConfiguration);}Maps.computeIfAbsent(ENTITY_MAPPER_CLASS_CACHE,entityClass,k - {Class? dynamicMapper new ByteBuddy().makeInterface(TypeDescription.Generic.Builder.parameterizedType(IMapper.class, entityClass).build()).name(String.format(%s.%sMapper,PluginConst.DYNAMIC_MAPPER_PREFIX, entityClass.getSimpleName())).make().load(ClassUtils.class.getClassLoader()).getLoaded();configuration.addMapper(dynamicMapper);return dynamicMapper;});}以上就是项目初始化的流程StreamQuery帮助我们完成了根据Entity来自动生成Mapper接下来我们分析一下StreamQuery是如何帮助我们简化使用的。
Database#saveFewSql(java.util.CollectionT)保存操作获取SqlSession获取IMapper执行saveFewSql的方法。 public static T boolean saveFewSql(CollectionT entityList) {return saveFewSql(entityList, PluginConst.DEFAULT_BATCH_SIZE);}public static T boolean saveFewSql(CollectionT entityList, int batchSize) {if (CollectionUtils.isEmpty(entityList) || batchSize 0) {return false;}return execute(getEntityClass(entityList),(IMapperT baseMapper) -entityList.size() baseMapper.saveFewSql(entityList, batchSize));}public static T, R, M extends BaseMapperT R execute(ClassT entityClass, SFunctionM, R sFunction) {SqlSession sqlSession SqlHelper.sqlSession(entityClass);try {return sFunction.apply(getMapper(entityClass, sqlSession));} finally {SqlSessionUtils.closeSqlSession(sqlSession, GlobalConfigUtils.currentSessionFactory(entityClass));}}IMapper#saveFewSql默认实现是批量拆分List调用saveOneSql。 /*** 批量插入** param list 集合* param batchSize 分割量* return 是否成功*/default long saveFewSql(CollectionT list, int batchSize) {return Steam.of(list).splitList(batchSize).mapToLong(this::saveOneSql).sum();}补充了解
One
One返回单个实体类。通过封装Database来完成查询单个操作。 /*** query.** return a V object*/public V query() {return Sf.of(Database.getOne(wrapper)).mayAlso(peekConsumer).mayLet(valueOrIdentity()).get();}QueryCondition
QueryCondition查询条件类继承了LambdaQueryWrapper。
也就是new LambdaQueryWrapperUserInfo().in(UserInfo::getName, Lists.of(张三, 李四));等于QueryConditionUserInfo wrapper QueryCondition.query(UserInfo.class).in(UserInfo::getName, Lists.of(张三, 李四));
public class QueryConditionT extends LambdaQueryWrapperT {public static T QueryConditionT query(ClassT entityClass) {QueryConditionT condition new QueryCondition();condition.setEntityClass(entityClass);return condition;}OneToOne
OneToOne封装了一层Stream的操作。 public MapK, V query() {return query(HashMap::new);}/*** query.** param mapFactory a {link java.util.function.IntFunction} object* param R a R class* return a R object*/public R extends MapK, V R query(IntFunctionR mapFactory) {ListT list Database.list(wrapper);return Steam.of(list).parallel(isParallel).peek(peekConsumer).toMap(keyFunction,valueOrIdentity(),SerBiOp.justAfter(),() - mapFactory.apply(list.size()));}AsyncHelper
AsyncHelper使用 public static void main(String[] args) {ListString result AsyncHelper.supply(() - {System.out.println(Thread.currentThread().getName() 1111);return 123;}, () - {System.out.println(Thread.currentThread().getName() 2345);return 456;});System.out.println(result);}原理分析可以指定拦截器和线程池使用CompletableFuture.supplyAsync来完成异步执行。 SafeVarargspublic static T ListT supply(AsyncConfig asyncConfig, SerSuppT... suppliers) {AsyncInterceptor interceptor asyncConfig.getInterceptor();interceptor.before();CompletableFutureT[] futures (CompletableFuture[])Steam.of(suppliers).map((supplier) - {return CompletableFuture.supplyAsync(() - {return interceptor.execute(supplier);}, asyncConfig.getExecutor());}).toArray((x$0) - {return new CompletableFuture[x$0];});CompletableFuture var10000 CompletableFuture.allOf(futures);interceptor.getClass();CompletableFutureVoid exceptionally var10000.exceptionally(interceptor::onError);(() - {return asyncConfig.getTimeout() -1 ? exceptionally.get() : exceptionally.get((long)asyncConfig.getTimeout(), asyncConfig.getTimeUnit());}).get();interceptor.after();return Steam.of(futures).map(CompletableFuture::get).toList();}
