@EnableJpaRepositories注解用于Srping JPA的代码配置,用于取代xml形式的配置文件,@EnableJpaRepositories支持的配置形式丰富多用,本篇文章详细讲解。
1、简单配置
1 @EnableJpaRepositories("com.spr.repository")
简单配置支持多个package,格式如下:
1 @EnableJpaRepositories({"com.cshtong.sample.repository", "com.cshtong.tower.repository"})
2、单值和多组值配置方式
大部分注解可以都支持单个注解方式和多个注解,多个注解通常采用"{}"符号包含的一组数据。
比如:字符串形式的 "x.y.z" => {"x.y.z","a.b.c"}
类别: A.class => {A.class, B.class}
3、完整的@EnableJpaRepositories注解
1 @EnableJpaRepositories( 2 basePackages = {}, 3 basePackageClasses = {}, 4 includeFilters = {}, 5 excludeFilters = {}, 6 repositoryImplementationPostfix = "Impl", 7 namedQueriesLocation = "",//META-INF/jpa-named-queries.properties 8 queryLookupStrategy=QueryLookupStrategy.Key.CREATE_IF_NOT_FOUND, //QueryLookupStrategy.Key.x 9 repositoryFactoryBeanClass=JpaRepositoryFactoryBean.class, //class 10 entityManagerFactoryRef="entityManagerFactory", 11 transactionManagerRef="transactionManager", 12 considerNestedRepositories=false, 13 enableDefaultTransactions=true 14 )
下面分别解释各个配置项的作用
1)basePackage
用于配置扫描Repositories所在的package及子package。简单配置中的配置则等同于此项配置值,basePackages可以配置为单个字符串,也可以配置为字符串数组形式。
1 @EnableJpaRepositories( 2 basePackages = "com.cshtong")
多个包路径
1 @EnableJpaRepositories( 2 basePackages = {"com.cshtong.sample.repository", "com.cshtong.tower.repository"})
2)basePackageClasses
指定 Repository 类
1 @EnableJpaRepositories(basePackageClasses = BookRepository.class)
1 @EnableJpaRepositories( 2 basePackageClasses = {ShopRepository.class, OrganizationRepository.class})
备注:测试的时候发现,配置包类的一个Repositories类,该包内其他Repositores也会被加载
3)includeFilters
过滤器,该过滤区采用ComponentScan的过滤器类
1 @EnableJpaRepositories( 2 includeFilters={@ComponentScan.Filter(type=FilterType.ANNOTATION, value=Repository.class)})
4)excludeFilters
不包含过滤器
1 @EnableJpaRepositories( 2 excludeFilters={ 3 @ComponentScan.Filter(type=FilterType.ANNOTATION, value=Service.class), 4 @ComponentScan.Filter(type=FilterType.ANNOTATION, value=Controller.class)})
5)repositoryImplementationPostfix
实现类追加的尾部,比如ShopRepository,对应的为ShopRepositoryImpl
6)namedQueriesLocation
named SQL存放的位置,默认为META-INF/jpa-named-queries.properties
7)queryLookupStrategy
构建条件查询的策略,包含三种方式CREATE,USE_DECLARED_QUERY,CREATE_IF_NOT_FOUND
CREATE:按照接口名称自动构建查询
USE_DECLARED_QUERY:用户声明查询
CREATE_IF_NOT_FOUND:先搜索用户声明的,不存在则自动构建
该策略针对如下通过接口名称自动生成查询的场景
List<Person> findByEmailAddressAndLastname(EmailAddress emailAddress, String lastname); // Enables the distinct flag for the query List<Person> findDistinctPeopleByLastnameOrFirstname(String lastname, String firstname); List<Person> findPeopleDistinctByLastnameOrFirstname(String lastname, String firstname); // Enabling ignoring case for an individual property List<Person> findByLastnameIgnoreCase(String lastname); // Enabling ignoring case for all suitable properties List<Person> findByLastnameAndFirstnameAllIgnoreCase(String lastname, String firstname); // Enabling static ORDER BY for a query List<Person> findByLastnameOrderByFirstnameAsc(String lastname); List<Person> findByLastnameOrderByFirstnameDesc(String lastname)
8)repositoryFactoryBeanClass
指定Repository的工厂类
9)entityManagerFactoryRef
实体管理工厂引用名称,对应到@Bean注解对应的方法