組件注冊
用@Bean來注冊
搭建好maven web工程
pom加入spring-context，spring-core等核心依賴
創(chuàng)建實(shí)例類com.hjj.bean.Person, 生成getter,setter方法
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public class Person { private String name; private int age;} |
創(chuàng)建com.hjj.config.MainConfig
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@Configuration //告訴spring是一個(gè)配置類public class MainConfig { // 給容器中注冊一個(gè)Bean，類行為返回值的類型，id默認(rèn)是用方法名作為id @Bean("mikePerson") public Person person(){ return new Person("mike",20); }} |
主測試類
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public class MainTest { public static void main(String[] args) { AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfig.class); Person bean = applicationContext.getBean(Person.class); System.out.println(bean); String[] beanNamesForType = applicationContext.getBeanNamesForType(Person.class); for (String type : beanNamesForType) { System.out.println(type); //配置類中的方法名,注意：通過修改配置類的@bean value也可以修改 } }} |
@ComponentScan包掃描
配置類中MainConfig.java
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@Configuration //告訴spring是一個(gè)配置類@ComponentScan("com.hjj") // 掃描包的路徑public class MainConfig { // 給容器中注冊一個(gè)Bean，類行為返回值的類型，id默認(rèn)是用方法名作為id @Bean("mikePerson") public Person person(){ return new Person("mike",20); }} |
新建測試的com.hjj.controller，service，dao
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@Controllerpublic class BookController {}@Repositorypublic class BookDao {}@Servicepublic class BookService {} |
單元測試
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@Testpublic void test01(){ AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfig.class); String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames(); //獲取所有組件 for (String beanDefinitionName : beanDefinitionNames) { System.out.println(beanDefinitionName); }} |
ComponentScan字段，有includeFilter(),和excludeFilter() 只包含或排除某些組件
@ComponentScan(value = "com.hjj",excludeFilters={@Filter(type=FilterType.ANNOTATION,classes={Controller.class,Service.class})})
@ComponentScan(value = "com.hjj",includeFilters={@Filter(type=FilterType.ANNOTATION,classes={Controller.class,Service.class})},userDefaultFilters=false)// excludeFilter源碼
ComponentScan.Filter[] excludeFilters() default {};
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// ComponentScan.Filter源碼@Retention(RetentionPolicy.RUNTIME)@Target({})public @interface Filter { FilterType type() default FilterType.ANNOTATION; @AliasFor("classes") Class<?>[] value() default {}; @AliasFor("value") Class<?>[] classes() default {}; String[] pattern() default {};} |
@ComponentScan被@Repeatable(ComponentScans.class)，可以重復(fù)寫，用來寫不同的執(zhí)行策略。
@ComponentScans 里面可以放ComponentScan類型的值
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@Retention(RetentionPolicy.RUNTIME)@Target({ElementType.TYPE})@Documentedpublic @interface ComponentScans { ComponentScan[] value();} |
FilterType
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public enum FilterType { ANNOTATION, // 按注解掃描 ASSIGNABLE_TYPE, // 按給定的類型 ASPECTJ, // 可以用aspectJ表達(dá)式 REGEX, // 正則表達(dá)式 CUSTOM; // 自定義規(guī)則 private FilterType() { }} |
ASSIGNABLE_TYPE
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@ComponentScan(value = "com.hjj",includeFilters ={@ComponentScan.Filter(type=FilterType.ASSIGNABLE_TYPE,classes = {BookService.class})})// config配置如上注解后 bookservice，可以被發(fā)現(xiàn) @Test public void demoTest1(){ AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfig.class); String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames(); for (String beanDefinitionName : beanDefinitionNames) { System.out.println(beanDefinitionName); } } |
Custom 可以自定義配置或?qū)憳I(yè)務(wù)掃描類的信息，match返回true則是加到組件
1.復(fù)寫TypeFilter的match方法
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public class MyTypeFilter implements TypeFilter { /** * * @param metadataReader 讀取到的當(dāng)前正在掃描的類的信息 * @param metadataReaderFactory 可以獲取到其他任何類信息 * @return * @throws IOException */ @Override public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) throws IOException { // 獲取當(dāng)前類注解的信息 AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata(); // 獲取當(dāng)前正在掃描類的信息 ClassMetadata classMetadata = metadataReader.getClassMetadata(); // 獲取當(dāng)前類資源（類的路徑等） Resource resource = metadataReader.getResource(); String className = classMetadata.getClassName(); System.out.println("className:" + className); return false; }} |
2. 加上注解
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@Configuration //告訴spring是一個(gè)配置類@ComponentScan(value = "com.hjj",includeFilters ={ @ComponentScan.Filter(type=FilterType.CUSTOM,classes = {MyTypeFilter.class})}, useDefaultFilter=false)public class MainConfig {}@Testpublic void test01(){AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfig.class);String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();for (String beanDefinitionName : beanDefinitionNames) {System.out.println(beanDefinitionName);}} |
結(jié)果
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className:com.hjj.test.IOCTestclassName:com.hjj.MainTestclassName:com.hjj.bean.PersonclassName:com.hjj.config.MyTypeFilterclassName:com.hjj.demo.DemoTestclassName:com.hjj.demo.EmployeeclassName:com.hjj.demo.Managerorg.springframework.context.annotation.internalConfigurationAnnotationProcessororg.springframework.context.annotation.internalAutowiredAnnotationProcessororg.springframework.context.annotation.internalCommonAnnotationProcessororg.springframework.context.event.internalEventListenerProcessororg.springframework.context.event.internalEventListenerFactorymainConfig |
以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持服務(wù)器之家。
原文鏈接：https://www.cnblogs.com/jimmyhe/p/13549493.html
