租赁公司网站源码,新媒体运营需要具备哪些能力,91游戏中心,网站建设seoppt文章目录 简介源码分析示例代码示例一#xff1a;扩展点的执行顺序运行示例一 示例二#xff1a;获取配置文件值配置文件application.properties内容定义工具类ConfigUtilcontroller测试调用运行示例二 示例三#xff1a;实现ResourceLoaderAware读取文件ExtendResourceLoad… 文章目录 简介源码分析示例代码示例一扩展点的执行顺序运行示例一 示例二获取配置文件值配置文件application.properties内容定义工具类ConfigUtilcontroller测试调用运行示例二 示例三实现ResourceLoaderAware读取文件ExtendResourceLoaderAware 文件内容token.json 文件controller测试代码运行示例三 简介
spring容器中Bean的生命周期内所有可扩展的点的调用顺序 扩展接口 实现接口ApplicationContextlnitializer initialize AbstractApplicationContext refreshe BeanDefinitionRegistryPostProcessor postProcessBeanDefinitionRegistry BeanDefinitionRegistryPostProcessor postProcessBeanFactory BeanFactoryPostProcessor postProcessBeanFactory instantiationAwareBeanPostProcessor postProcessBeforelnstantiation SmartlnstantiationAwareBeanPostProcessor determineCandidateConstructors MergedBeanDefinitionPostProcessor postProcessMergedBeanDefinition InstantiationAwareBeanPostProcessor postProcessAfterlnstantiation SmartInstantiationAwareBeanPostProcessor getEarlyBeanReference BeanNameAware setBeanName BeanFactoryAware postProcessPropertyValues ApplicationContextAwareProcessor invokeAwarelnterfaces InstantiationAwareBeanPostProcessor postProcessBeforelnstantiation PostConstructInitializingBean afterPropertiesSet FactoryBean getobject SmartlnitializingSingleton afterSingletonslnstantiated CommandLineRunner runDisposableBeandestroy 今天要介绍的是ApplicationContextAwareProcessor ApplicationContextAwareProcessor 本身是没有扩展点的但其内部却有7个扩展点可供实现 分别为
EnvironmentAwareEmbeddedValueResolverAwareResourceLoaderAwareApplicationEventPublisherAwareMessageSourceAwareApplicationStartupAwareApplicationContextAware
这些内部扩展点触发的时机在bean实例化之后初始化之前。
1、EnvironmentAware凡注册到Spring容器内的bean实现了EnvironmentAware接口重写setEnvironment方法后在工程启动时可以获得application.properties的配置文件配置的属性值。 2、EmbeddedValueResolverAware用于获取StringValueResolver的一个扩展类 StringValueResolver用于获取基于String类型的properties的变量 3、ResourceLoaderAware用于获取ResourceLoader的一个扩展类ResourceLoader可以用于获取classpath内所有的资源对象可以扩展此类来拿到ResourceLoader对象。 4、ApplicationEventPublisherAware用于获取ApplicationEventPublisher的一个扩展类ApplicationEventPublisher可以用来发布事件结合ApplicationListener来共同使用 5、MessageSourceAware用于获取MessageSource的一个扩展类MessageSource主要用来做国际化 6、ApplicationStartupAware要开始收集定制的StartupStep组件可以实现ApplicationStartupAware接口直接获得ApplicationStartup实例或者在注入点请求ApplicationStartup类型。 7、ApplicationContextAware可以用来获取ApplicationContext的一个扩展类也就是spring上下文管理器可以手动的获取任何在spring上下文注册的bean
源码分析
从下列源码的invokeAwareInterfaces方法可知ApplicationContextAwareProcessor关联了大部分Spring内置Aware接口,它们的执行顺序如 下源码码所示从上到下最开始是EnvironmentAware最后是ApplicationContextAware
package org.springframework.context.support;class ApplicationContextAwareProcessor implements BeanPostProcessor {private final ConfigurableApplicationContext applicationContext;private final StringValueResolver embeddedValueResolver;/*** Create a new ApplicationContextAwareProcessor for the given context.*/public ApplicationContextAwareProcessor(ConfigurableApplicationContext applicationContext) {this.applicationContext applicationContext;this.embeddedValueResolver new EmbeddedValueResolver(applicationContext.getBeanFactory());}OverrideNullablepublic Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {if (!(bean instanceof EnvironmentAware || bean instanceof EmbeddedValueResolverAware ||bean instanceof ResourceLoaderAware || bean instanceof ApplicationEventPublisherAware ||bean instanceof MessageSourceAware || bean instanceof ApplicationContextAware ||bean instanceof ApplicationStartupAware)) {return bean;}AccessControlContext acc null;if (System.getSecurityManager() ! null) {acc this.applicationContext.getBeanFactory().getAccessControlContext();}if (acc ! null) {AccessController.doPrivileged((PrivilegedActionObject) () - {invokeAwareInterfaces(bean);return null;}, acc);}else {invokeAwareInterfaces(bean);}return bean;}private void invokeAwareInterfaces(Object bean) {if (bean instanceof EnvironmentAware) {((EnvironmentAware) bean).setEnvironment(this.applicationContext.getEnvironment());}if (bean instanceof EmbeddedValueResolverAware) {((EmbeddedValueResolverAware) bean).setEmbeddedValueResolver(this.embeddedValueResolver);}if (bean instanceof ResourceLoaderAware) {((ResourceLoaderAware) bean).setResourceLoader(this.applicationContext);}if (bean instanceof ApplicationEventPublisherAware) {((ApplicationEventPublisherAware) bean).setApplicationEventPublisher(this.applicationContext);}if (bean instanceof MessageSourceAware) {((MessageSourceAware) bean).setMessageSource(this.applicationContext);}if (bean instanceof ApplicationStartupAware) {((ApplicationStartupAware) bean).setApplicationStartup(this.applicationContext.getApplicationStartup());}if (bean instanceof ApplicationContextAware) {((ApplicationContextAware) bean).setApplicationContext(this.applicationContext);}}
}示例代码
示例一扩展点的执行顺序
示例一展示的是7个内部扩展点所执行的顺序
Slf4j
Configuration
public class ExtendInvokeAware implements EnvironmentAware, EmbeddedValueResolverAware, ResourceLoaderAware,ApplicationEventPublisherAware, MessageSourceAware, ApplicationStartupAware, ApplicationContextAware, BeanNameAware {Overridepublic void setApplicationContext(ApplicationContext applicationContext) throws BeansException {log.info(setApplicationContext--Extend--run {},applicationContext);}Overridepublic void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {log.info(setApplicationEventPublisher--Extend--run {},applicationEventPublisher);}Overridepublic void setApplicationStartup(ApplicationStartup applicationStartup) {log.info(setApplicationStartup--Extend--run {},applicationStartup);}Overridepublic void setEmbeddedValueResolver(StringValueResolver resolver) {log.info(setEmbeddedValueResolver--Extend--run {},resolver);}Overridepublic void setEnvironment(Environment environment) {log.info(setEnvironment--Extend--run {},environment);}Overridepublic void setMessageSource(MessageSource messageSource) {log.info(setMessageSource--Extend--run {},messageSource);}Overridepublic void setResourceLoader(ResourceLoader resourceLoader) {log.info(setResourceLoader--Extend--run {},resourceLoader);}Overridepublic void setBeanName(String name) {log.info(setBeanName--Extend--run {},name);}
}运行示例一 示例二获取配置文件值
展示如何利用实现EmbeddedValueResolverAware来获取配置文件的属性值
配置文件application.properties内容
db.usernavicat
db.passwordnavicat
db.driverClasscom.mysql.jdbc.Driver定义工具类ConfigUtil
该工具类功能为传入的key获取对应value
Component
public class ConfigUtil implements EmbeddedValueResolverAware {private StringValueResolver resolver;Overridepublic void setEmbeddedValueResolver(StringValueResolver resolver) {this.resolver resolver;}/*** 获取属性直接传入属性名称即可* param key* return*/public String getPropertiesValue(String key) {StringBuilder name new StringBuilder(${).append(key).append(});return resolver.resolveStringValue(name.toString());}}controller测试调用
GetMapping(/testConfig)
public void testConfig() {String s configUtil.getPropertiesValue(db.user);System.out.println(s);
}运行示例二 示例三实现ResourceLoaderAware读取文件
ExtendResourceLoaderAware 文件内容
实现ResourceLoaderAware 接口并读取文件内容进行打印
Slf4j
Configuration
public class ExtendResourceLoaderAware implements ResourceLoaderAware {private ResourceLoader resourceLoader;Overridepublic void setResourceLoader(ResourceLoader resourceLoader) {this.resourceLoader resourceLoader;log.info(ApplicationContextAware--Extend--run {},resourceLoader);}public void showResourceData() throws IOException{//This line will be changed for all versions of other examplesResource banner resourceLoader.getResource(file:d:/token.json);InputStream in banner.getInputStream();BufferedReader reader new BufferedReader(new InputStreamReader(in));while (true) {String line reader.readLine();if (line null)break;System.out.println(line);}reader.close();}
}token.json 文件
{name:张三}controller测试代码
Autowired
ApplicationContext context;SuppressWarnings(resource)
GetMapping(/testResource)
public void testResource() throws Exception{ExtendResourceLoaderAware extendResourceLoaderAware (ExtendResourceLoaderAware) context.getBean(extendResourceLoaderAware);extendResourceLoaderAware.showResourceData();
}运行示例三
