通江县住房和城乡建设局网站,专业做毕业设计网站,深圳中高风险地区,网站培训网站建设SpringBoot有哪些扩展点 aware 感知类接口 aware系列的扩展接口#xff0c;允许spring应用感知/获取特定的上下文环境或对象。bean生命周期控制类接口 bean生命周期类的接口#xff0c;可以控制spring容器对bean的处理。app生命周期控制类接口 app生命周期控制类接口#xf…SpringBoot有哪些扩展点 aware 感知类接口 aware系列的扩展接口允许spring应用感知/获取特定的上下文环境或对象。bean生命周期控制类接口 bean生命周期类的接口可以控制spring容器对bean的处理。app生命周期控制类接口 app生命周期控制类接口可以控制spring应用启动/销毁时的逻辑下面详细介绍各种扩展点的使用
aware 感知类接口
ApplicationContextAware
package cn.test.ext.aware;import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;import java.util.Arrays;/*** ApplicationContextAware* 通过实现该接口组件可以获取ApplicationContext对象的引用* 从而访问应用程序上下文中的bean以及其他特定的spring功能*/
Component
Slf4j
public class TestAppCtxAware implements ApplicationContextAware {Overridepublic void setApplicationContext(ApplicationContext applicationContext) throws BeansException {String applicationName applicationContext.getApplicationName();log.info(context-path:{},applicationName);String displayName applicationContext.getDisplayName();log.info(displayName:{},displayName);String id applicationContext.getId();log.info(spring-applicationName:{},id);long startupDate applicationContext.getStartupDate();log.info(startupDate:{},startupDate);
// String[] beanDefinitionNames applicationContext.getBeanDefinitionNames();
// log.info(beanDefinitionNames:{}, Arrays.asList(beanDefinitionNames).toString());}
}
BeanFactoryAware
package cn.test.ext.aware;import cn.test.web.TestController;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.stereotype.Component;/*** BeanFactoryAware* 实现该接口可以使自定义类获取bean工厂对象的引用* 允许你在运行时从bean工厂中获取其他bean*/
Slf4j
Component
public class TestBeanFactoryAware implements BeanFactoryAware {Overridepublic void setBeanFactory(BeanFactory beanFactory) throws BeansException {boolean b beanFactory.containsBean(testController);log.info(spring容器内是否含有 testController这个bean :{},b);TestController testController (TestController) beanFactory.getBean(testController);String tgwt43t testController.t1(tgwt43t);log.info(get bean方式调用 TestController里的t1方法,返回值:{},tgwt43t);}
}
EnvironmentAware
package cn.test.ext.aware;import lombok.extern.slf4j.Slf4j;
import org.springframework.context.EnvironmentAware;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;import java.util.Arrays;/*** EnvironmentAware* 实现该接口你的组件可以获取 Environment 环境对象的引用* 从而可以访问spring应用程序的配置属性和配置文件*/
Component
Slf4j
public class TestEnvironmentAware implements EnvironmentAware {Overridepublic void setEnvironment(Environment environment) {//获取当前默认的profile环境String[] defaultProfiles environment.getDefaultProfiles();log.info(defaultProfiles:{},Arrays.asList(defaultProfiles));//获取某个属性配置String property environment.getProperty(spring.application.name);log.info(property-spring.application.name:{},property);}
}
MessageSourceAware
package cn.test.ext.aware;import lombok.extern.slf4j.Slf4j;
import org.springframework.context.MessageSource;
import org.springframework.context.MessageSourceAware;
import org.springframework.stereotype.Component;/*** MessageSourceAware* 实现该接口你的组件可以获取 messageSource 消息源对象的引用,* 从而访问 国际化消息内容*/
Component
Slf4j
public class TestMessageSourceAware implements MessageSourceAware {Overridepublic void setMessageSource(MessageSource messageSource) {
// messageSource.getMessage()}
}
ResourceLoaderAware
package cn.test.ext.aware;import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ResourceLoaderAware;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.stereotype.Component;import java.util.Properties;/*** ResourceLoaderAware* 实现该接口你的组件可以获取 ResourceLoader 资源加载器 对象的引用。* 从而可以加载外部资源文件*/
Slf4j
Component
public class TestResourceLoaderAware implements ResourceLoaderAware {SneakyThrowsOverridepublic void setResourceLoader(ResourceLoader resourceLoader) {//ResourceLoader可以加载自定义位置的自定义的properties配置文件//这里测试加载classpath下的test.properties文件Resource resource resourceLoader.getResource(classpath:test.properties);if (resource.isFile()) {String filename resource.getFilename();log.info(filename:{},filename);Properties properties new Properties();properties.load(resource.getInputStream());properties.list(System.out);String aaa properties.getProperty(aaa);log.info(aaa--:{},aaa);}}
}
ServletContextAware
package cn.test.ext.aware;import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.context.ServletContextAware;import javax.servlet.ServletContext;/*** ServletContextAware* 实现该接口你的组件可以获取 ServletContext Servlet上下文对象的引用* 从而访问与web应用程序相关的功能*/
Component
Slf4j
public class TestServletContextAware implements ServletContextAware {Overridepublic void setServletContext(ServletContext servletContext) {//添加java web 过滤器
// servletContext.addFilter()//添加java web servlet
// servletContext.addServlet()//添加java web 监听器
// servletContext.addListener();}
}
bean生命周期控制类接口
InitializingBean
package cn.test.ext.beanlife;import cn.test.ext.ITestStrategy;
import cn.test.ext.MyStrategyFactory;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.stereotype.Component;/*** InitializingBean* 实现该接口你的bean可以在 spring容器初始化当前bean时 执行自定义逻辑** 必须在afterPropertiesSet方法里写你自定义的执行逻辑*/
Slf4j
Component
public class TestInitializingBean implements ITestStrategy, InitializingBean {private static String str ;//实现InitializingBean接口必须重写afterPropertiesSet方法//这样当springboot启动加载TestInitializingBean时会自动执行里边的afterPropertiesSet方法Overridepublic void afterPropertiesSet() throws Exception {//本方法里可以做一些初始化的操作如设置类静态变量值 / 将类注册到策略工厂/ 执行一些其他方法或动作/...//设置类静态变量值str qwe123!;//将k1策略 (本类) 注册到 策略工厂里MyStrategyFactory.register(k1,this);log.info(注册了策略:{}到策略工厂里,this);}Overridepublic void execTestMethod() {log.info(start----执行k1策略...);System.err.println(str);}
}
DisposableBean
package cn.test.ext.beanlife;import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.stereotype.Component;/*** DisposableBean* 实现该接口你的bean可以在销毁阶段执行自定义逻辑。* 该接口包含一个destory(),你可以在此方法中定义销毁逻辑。*/
Slf4j
Component
public class TestDisposableBean implements DisposableBean {Overridepublic void destroy() throws Exception {log.info(TestDisposableBean 这个bean销毁了...);}
}
BeanPostProcessor
package cn.test.ext.beanlife;import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.stereotype.Component;/*** BeanPostProcessor* 该接口定义了在spring容器实例化bean之后和初始化之前* 对bean进行自定义处理的方法。* 通过实现该接口你可以插入自定义逻辑来处理bean*/
Component
Slf4j
public class TestBeanPostProcessor implements BeanPostProcessor {public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {if (beanName.equals(testController)){log.info(BeanPostProcessor Before 处理到了 beanName:{},beanName);}return bean;}public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {if (beanName.equals(testController)){log.info(BeanPostProcessor After 处理到了 beanName:{},beanName);}return bean;}
}
BeanFactoryPostProcessor
package cn.test.ext.beanlife;import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.stereotype.Component;/*** BeanFactoryPostProcessor接口* 允许在 所有bean定义加载到容器之后,但在bean实例化之前对他们进行自定义处理。* 通过实现该接口你可以修改或添加新的bean定义***/
Component
Slf4j
public class TestBeanFctoryPostProcessor implements BeanFactoryPostProcessor {Overridepublic void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException {log.info(postProcessBeanFactory 触发了....);}
}
BeanDefinitionRegistryPostProcessor
package cn.test.ext.beanlife;import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
import org.springframework.stereotype.Component;/*** BeanDefinitionRegistryPostProcessor接口** 这个接口是BeanFactoryPostProcessor接口的扩展* 允许在bean定义注册过程中对 bean定义进行自定义处理* 它提供了对bean定义注册表的直接访问可以添加修改或删除bean定义*/
Slf4j
Component
public class TestBeanDefineRegistPostProcessor implements BeanDefinitionRegistryPostProcessor {Overridepublic void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry beanDefinitionRegistry) throws BeansException {log.info(postProcessBeanDefinitionRegistry 触发了...);}Overridepublic void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException {log.info(postProcessBeanFactory 触发了...);}
}
app生命周期控制类接口
SmartLifecycle
package cn.test.ext.applife;import lombok.extern.slf4j.Slf4j;
import org.springframework.context.SmartLifecycle;
import org.springframework.stereotype.Component;/*** SmartLifecycle接口 可以感知springboot应用生命周期变化是spring的一个扩展点可以实现随springboot启动和销毁的操作。** 自定义类实现SmartLifecycle接口后至少要重写3个方法start(),stop(),isRunning() ,其他方法可以按需实现** springboot中的内嵌tomcat启动/关闭就是利用SmartLifecycle实现的* 见 org.springframework.boot.web.servlet.context.WebServerStartStopLifecycle*/
Component
Slf4j
public class TestSmartLifeCycle implements SmartLifecycle {//模拟一个任务 (实际开发中可以在这里引入netty实现netty随springboot启动和销毁)private static boolean xxxStat;/*** bean初始化完毕后该方法会被执行*/Overridepublic void start() {xxxStat true;log.info(启动了 xxxStat );}/*** 容器关闭后,spring容器发现当前对象实现了SmartLifecycle* 就调用stop(Runnable),如果只是实现了Lifecycle,就调用stop()*/Overridepublic void stop() {log.info(stop---容器关闭了);xxxStat false;}/*** 当前状态* return*/Overridepublic boolean isRunning() {log.info(isRunning 获取当前状态:{},xxxStat);return xxxStat;}/*** start方法被执行前先看此方法返回值,* 返回false就不执行start方法了* return*/Overridepublic boolean isAutoStartup() {log.info(isAutoStartup 是否自启动);return true;}/*** 容器关闭后,spring容器发现当前对象实现了SmartLifecycle就调用stop(Runnable),* 如果只是实现了Lifecycle,就调用stop()* param callback*/Overridepublic void stop(Runnable callback) {//必须调用stop方法 ,确保SmartLifecycle这个bean里的任务停止了this.stop();//必须执行callback.run方法否则app exit时无法销毁这个SmartLifecyclecallback.run();log.info(stop Runnable---容器关闭了);}/*** 返回值决定* start方法 在众多Lifecycle实现类中的执行顺序(stop也是)* return*/Overridepublic int getPhase() {log.info(SmartLifecycle 当前优先级 1);return 1;}
}
CommandLineRunner
CommandLineRunner可以让springboot-jar启动时接收一些jvm参数或自定义cmd参数然后执行一些操作
package cn.test.ext.applife;import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;Slf4j
Component
public class TestCmdLineRunner implements CommandLineRunner {Overridepublic void run(String... args) throws Exception {log.info(CommandLineRunner 执行了...);}
}
ApplicationRunner
ApplicationRunner可以让springboot-jar启动时接收一些应用配置参数如server.port然后执行一些操作
package cn.test.ext.applife;import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;Slf4j
Component
public class TestApplictionRunner implements ApplicationRunner {Overridepublic void run(ApplicationArguments args) throws Exception {log.info(ApplicationRunner 执行了...);}
}
ApplicationListener
要通过spring内置的ApplicationListener监听ContextRefreshedEvent 上下文刷新事件springboot启动时会触发一次 一般常用来做业务缓存预热如在springboot启动时把系统字典数据/系统配置项数据加到缓存中方便后续调用。
package cn.test.ext.applife;import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;
Slf4j
Component
public class AppCtxRefreshListener implements ApplicationListenerContextRefreshedEvent {/*** 监听到上下文刷新事件时* 执行相应的操作* param contextRefreshedEvent 上下文刷新事件*/Overridepublic void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {log.info(监听到了spring应用 上下文刷新事件...);}
}
