02. Interpretation of Spring's underlying core concepts

Tech 2023-05-16 09:01:46 Source: Network

BeanDefinitionBeanDefinitonBeanBeanDefinitionBeanclassBeanscopeBeanBeanlazylnitBeanintMethodNameBeandestroyMethodNameBean.

BeanDefinition

BeanDefinitonBeanBeanDefinitionBean

classBean
scopeBeanBean
lazylnitBean
intMethodNameBean
destroyMethodNameBean
....... spring

SpringBean

<bean/>
@Bean
@Component(@Service,@Controller)

Bean

BeanBeanDefinition

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);// BeanDefinitionbeanClassUser.classApplicationContextAbstractBeanDefinition beanDefinition = BeanDefinitionBuilder.genericBeanDefinition().getBeanDefintion();context.registerBeanDefinition("user", beanDefinition);System.out.println(context.getBean("user"));

BeanDefinitionBean

beanDefinition.setScope("prototype"); // beanDefinition.setInitMethodName("init"); // beanDefinition.setLazyInit(true); //

<bean/>@Bean@ComponentBeanSpringBeanDefinitionSpring

BeanDefinitionReader

SpringBeanDefinitionBeanDefinitionReaderBeanDefinitionReaderSpringSpringSpring

AnnotatedBeanDefinitionReader

BeanDefinition

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);AnnotatedBeanDefinitionReader annotatedBeanDefinitionReader = new AnnotatedBeanDefinitionReader(context);// User.classBeanDefinitionannotatedBeanDefinitionReader.register(User.class);System.out.println(context.getBean("user"));

@Conditional@Scope@Lazy@Primary@DependsOn@Role@Description

XmlBeanDefinitionReader

<bean/>

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);XmlBeanDefinitionReader xmlBeanDefinitionReader = new XmlBeanDefinitionReader(context);int i = xmlBeanDefinitionReader.loadBeanDefinitions("spring.xml");System.out.println(context.getBean("user"));

ClassPathBeanDefinitionScanner

ClassPathBeanDefinitionScannerBeanDefinitionReader@ComponentBeanDefinition

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();context.refresh();ClassPathBeanDefinitionScanner scanner = new ClassPathBeanDefinitionScanner(context);scanner.scan("com.zhouyu");System.out.println(context.getBean("userService"));

BeanFactory

BeanFactoryBeanBeanFactoryBeanBeanAPI
ApplicationContextBeanFactorySpring

public interface ApplicationContext extends EnvironmentCapable, ListableBeanFactory, HierarchicalBeanFactory,  MessageSource, ApplicationEventPublisher, ResourcePatternResolver {            ...}

JavaApplicationContextListableBeanFactoryHierarchicalBeanFactoryListableBeanFactoryHierarchicalBeanFactoryBeanFactoryApplicationContextBeanFactoryApplicationContextBeanFactoryBeanFactoryApplicationContextBeanFactoryApplicationContextApplicationContextMessageSourceApplicationEventPublisherEnvironmentCapableApplicationContext

SpringnewApplicationContextnewBeanFactoryApplicationContextgetBean()BeanFactorygetBean()
SpringBeanFactory**
DefaultListableBeanFactory**

DefaultListableBeanFactoryApplicationContext

DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();AbstractBeanDefinition beanDefinition = BeanDefinitionBuilder.genericBeanDefinition().getBeanDefinition();beanDefinition.setBeanClass(User.class);beanFactory.registerBeanDefinition("user", beanDefinition);System.out.println(beanFactory.getBean("user"));

DefaultListableBeanFactory
DefaultListableBeanFactory

AliasRegistry
BeanDefinitionRegistryBeanDefinition
BeanFactoryBeanbeanBean
SingletonBeanRegistryBean
SimpleAliasRegistryAliasRegistry
ListableBeanFactoryBeanFactoryBeanDefinitionbeanNamesbeanNames{Bean}
HierarchicalBeanFactoryBeanFactoryBeanFactory
DefaultSingletonBeanRegistrySingletonBeanRegistryBean
ConfigurableBeanFactoryHierarchicalBeanFactorySingletonBeanRegistryBeanFactorySpring ELBeanFactoryELBeanFactoryBeanPostProcessorBeanFactoryBeanBeanDefinitionBean
FactoryBeanRegistrySupportFactoryBean
AutowireCapableBeanFactoryBeanFactoryBeanFactoryBeanBean
AbstractBeanFactoryConfigurableBeanFactoryFactoryBeanRegistrySupportBeanFactorybeanNames
ConfigurableListableBeanFactoryListableBeanFactoryAutowireCapableBeanFactoryConfigurableBeanFactory
AbstractAutowireCapableBeanFactoryAbstractBeanFactoryAutowireCapableBeanFactory
DefaultListableBeanFactoryAbstractAutowireCapableBeanFactoryConfigurableListableBeanFactoryBeanDefinitionRegistryDefaultListableBeanFactory

ApplicationContext

ApplicationContextBeanFactoryBeanFactory

HierarchicalBeanFactoryBeanFactory
ListableBeanFactorybeanNames
ResourcePatternResolver
EnvironmentCapable
ApplicationEventPublisher
MessageSource

ApplicationContext

AnnotationConfigApplicationContext
ClassPathXmlApplicationContext

AnnotationConfigApplicationContext

ConfigurableApplicationContextApplicationContextBeanFactoryPostProcessorEnvironmentConfigurableListableBeanFactory
AbstractApplicationContextConfigurableApplicationContext
GenericApplicationContextAbstractApplicationContextBeanDefinitionRegistryApplicationContextBeanDefinition(DefaultListableBeanFactory beanFactory)
AnnotationConfigRegistryBeanDefinition**@Configuration****@Bean**
AnnotationConfigApplicationContextGenericApplicationContextAnnotationConfigRegistry

ClassPathXmlApplicationContext

AbstractApplicationContext
AnnotationConfigApplicationContext
AnnotationConfigApplicationContextBeanDefinition

MessageSource:

@Beanpublic MessageSource messageSource() { 	ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource(); 	messageSource.setBasename("messages"); 	return messageSource;}

BeanMessageSourceApplicationContext

context.getMessage("test", null, new Locale("en_CN"))

ApplicationContextApplicationContext

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);Resource resource = context.getResource("file:/home/IdeaProjects/spring-framework/src/main/java/com/eemp/entity/User.java");System.out.println(resource.contentLength());

ApplicationContext

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);Resource resource = context.getResource("file:/home/IdeaProjects/spring-framework/src/main/java/com/eemp/entity/UserService.java");System.out.println(resource.contentLength());System.out.println(resource.getFilename());Resource resource1 = context.getResource("https://www.baidu.com");System.out.println(resource1.contentLength());System.out.println(resource1.getURL());Resource resource2 = context.getResource("classpath:spring.xml");System.out.println(resource2.contentLength());System.out.println(resource2.getURL());

Resource[] resources = context.getResources("classpath:com/eemp/*.class");for (Resource resource : resources) { 	System.out.println(resource.contentLength()); 	System.out.println(resource.getFilename());}

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);Map<String, Object> systemEnvironment = context.getEnvironment().getSystemEnvironment();System.out.println(systemEnvironment);System.out.println("=======");Map<String, Object> systemProperties = context.getEnvironment().getSystemProperties();System.out.println(systemProperties);System.out.println("=======");MutablePropertySources propertySources = context.getEnvironment().getPropertySources();System.out.println(propertySources);System.out.println("=======");System.out.println(context.getEnvironment().getProperty("NO_PROXY"));System.out.println(context.getEnvironment().getProperty("sun.jnu.encoding"));System.out.println(context.getEnvironment().getProperty("eemp"));

@PropertySource("classpath:spring.properties")

properties.

@Beanpublic ApplicationListener applicationListener() {   return new ApplicationListener() {      @Override      public void onApplicationEvent(ApplicationEvent event) {       	System.out.println("");      }   };}

context.publishEvent("kkk");

SpringStringSpring

PropertyEditor

JDK

public class StringToUserPropertyEditor extends PropertyEditorSupport implements PropertyEditor { @Override public void setAsText(String text) throws IllegalArgumentException {      User user = new User();      user.setName(text);      this.setValue(user);   }}

StringToUserPropertyEditor propertyEditor = new StringToUserPropertyEditor();propertyEditor.setAsText("1");User value = (User) propertyEditor.getValue();System.out.println(value);

SpringPropertyEditor

@Beanpublic CustomEditorConfigurer customEditorConfigurer() {   CustomEditorConfigurer customEditorConfigurer = new CustomEditorConfigurer();   Map<Class<?>, Class<? extends PropertyEditor>> propertyEditorMap = new HashMap<>();      // StringToUserPropertyEditorStringUserSpringStringUserPropertyEditor   propertyEditorMap.put(User.class, StringToUserPropertyEditor.class);   customEditorConfigurer.setCustomEditors(propertyEditorMap);   return customEditorConfigurer;}

Bean:

@Componentpublic class UserService {   @Value("xxx")   private User user;   public void test() {    System.out.println(user);   }}

test

OrderComparator

OrderComparatorSpring@OrderOrdered

public class A implements Ordered {   @Override   public int getOrder() {      return 3;   }   @Override   public String toString() {      return this.getClass().getSimpleName();   }}

public class B implements Ordered {   @Override   public int getOrder() {   	 return 2;   }   @Override   public String toString() {    	return this.getClass().getSimpleName();   }}

public class Main {   public static void main(String[] args) {      A a = new A(); // order=3      B b = new B(); // order=2      OrderComparator comparator = new OrderComparator();      System.out.println(comparator.compare(a, b));  // 1      List list = new ArrayList<>();      list.add(a);      list.add(b);      // order      list.sort(comparator);      System.out.println(list);  // BA   }}

SpringOrderComparator
AnnotationAwareOrderComparator@Orderorder

@Order(3)public class A {   @Override   public String toString() {    	return this.getClass().getSimpleName();   }}@Order(2)public class B {   @Override   public String toString() {    	return this.getClass().getSimpleName();   }}public class Main {   public static void main(String[] args) {      A a = new A(); // order=3      B b = new B(); // order=2      AnnotationAwareOrderComparator comparator = new AnnotationAwareOrderComparator();      System.out.println(comparator.compare(a, b)); // 1      List list = new ArrayList<>();      list.add(a);      list.add(b);      // order      list.sort(comparator);      System.out.println(list); // BA   }}

BeanPostProcessor

BeanPostProcessBenaBeanPostProcessorBeanPostProcessor

@Componentpublic class MyBeanPostProcessor implements BeanPostProcessor {   @Override   public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {      if ("userService".equals(beanName)) {       System.out.println("");      }    	return bean;   }   @Override   public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {      if ("userService".equals(beanName)) {       System.out.println("");      }    	return bean;   }}

BeanPostProcessorBeanbeanNameBeanBean

BeanPostProcessorSpringBean

BeanFactoryPostProcessor

BeanFactoryPostProcessorBeanBeanPostProcessorBeanPostProcessorBeanBeanFactoryPostProcessorBeanFactoryBeanFactoryPostProcessor

@Componentpublic class MyBeanFactoryPostProcessor implements BeanFactoryPostProcessor {   @Override   public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {    	System.out.println("beanFactory");   }}

postProcessBeanFactory()BeanFactory

FactoryBean

BeanPostPorcessorSpringBeanBeanFactoryBean

@Componentpublic class MyFactoryBean implements FactoryBean {   @Override   public Object getObject() throws Exception {      UserService userService = new UserService();      return userService;   }   @Override   public Class<?> getObjectType() {    	return UserService.class;   }}

UserServiceBeanUserServiceBeanSpring

@BeanBeanFactoryBean@BeanBeanBean

ExcludeFilterIncludeFilter

FilterSpringExcludeFilterIncludeFilter

com.eempUserService@ComponentBean

@ComponentScan(value = "com.eemp",      excludeFilters = {@ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = UserService.class)})public class AppConfig {}

UserService@ComponentBean

@ComponentScan(value = "com.eemp",  includeFilters = {@ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = UserService.class)})public class AppConfig {}

FilterType

ANNOTATION
ASSIGNABLE_TYPE
ASPECTJAspectj
REGEX
CUSTOM

SpringAnnotationTypeFilterincludeFiltersSpring@ComponentBean

MetadataReaderClassMetadataAnnotationMetadata

SpringSpring

MetadataReaderSimpleMetadataReader

public class Test {  public static void main(String[] args) throws IOException {  	SimpleMetadataReaderFactory simpleMetadataReaderFactory = new SimpleMetadataReaderFactory();   	// MetadataReader   	MetadataReader metadataReader = simpleMetadataReaderFactory.getMetadataReader("com.eemp.service.UserService");   	// ClassMetadata   	ClassMetadata classMetadata = metadataReader.getClassMetadata();   	System.out.println(classMetadata.getClassName());   	// AnnotationMetadata   	AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata();   	for (String annotationType : annotationMetadata.getAnnotationTypes()) {        System.out.println(annotationType);    }   }}

SimpleMetadataReaderASM

ASMSpringSpringJVMASM

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Tag: Interpretation of Spring underlying core concepts