spring BeanFactory和ApplicatContext

【spring BeanFactory和ApplicatContext】今日长缨在手，何时缚住苍龙。这篇文章主要讲述spring BeanFactory和ApplicatContext相关的知识，希望能为你提供帮助。
spring容器
BeanFactory提供了IoC的功能；ApplicatContext建立在BeanFactory的基础上
BeanFactory顶层接口

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package org.springframework.beans.factory; import org.springframework.beans.BeansException; import org.springframework.core.ResolvableType; public interface BeanFactory { String FACTORY_BEAN_PREFIX = "& "; // getBean()方法从容器中返回Bean Object getBean(String var1) throws BeansException; < T> T getBean(String var1, Class< T> var2) throws BeansException; Object getBean(String var1, Object... var2) throws BeansException; < T> T getBean(Class< T> var1) throws BeansException; < T> T getBean(Class< T> var1, Object... var2) throws BeansException; // 容器里有没有一个Bean boolean containsBean(String var1); // 一个Bean是不是单例的 boolean isSingleton(String var1) throws NoSuchBeanDefinitionException; // 一个Bean是不是复例的 boolean isPrototype(String var1) throws NoSuchBeanDefinitionException; boolean isTypeMatch(String var1, ResolvableType var2) throws NoSuchBeanDefinitionException; boolean isTypeMatch(String var1, Class< ?> var2) throws NoSuchBeanDefinitionException; Class< ?> getType(String var1) throws NoSuchBeanDefinitionException; String[] getAliases(String var1); }

View CodeBeanFactory的子接口ListableBeanFactory

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package org.springframework.beans.factory; import java.lang.annotation.Annotation; import java.util.Map; import org.springframework.beans.BeansException; import org.springframework.core.ResolvableType; public interface ListableBeanFactory extends BeanFactory { // 是否包含特定的Bean boolean containsBeanDefinition(String var1); // 查看Bean的数量 int getBeanDefinitionCount(); String[] getBeanDefinitionNames(); String[] getBeanNamesForType(ResolvableType var1); String[] getBeanNamesForType(Class< ?> var1); String[] getBeanNamesForType(Class< ?> var1, boolean var2, boolean var3); < T> Map< String, T> getBeansOfType(Class< T> var1) throws BeansException; < T> Map< String, T> getBeansOfType(Class< T> var1, boolean var2, boolean var3) throws BeansException; String[] getBeanNamesForAnnotation(Class< ? extends Annotation> var1); Map< String, Object> getBeansWithAnnotation(Class< ? extends Annotation> var1) throws BeansException; < A extends Annotation> A findAnnotationOnBean(String var1, Class< A> var2) throws NoSuchBeanDefinitionException; }

View CodeBeanFactory的子接口HierarchicalBeanFactory
通过这个接口Spring的IoC容器可以建立父子层级关联的容器体系，子容器可以访问父容器中的Bean，但父容器不能访问子容器中的Bean。
AutowireCapableBeanFactory接口
定义了自动装配
DefaultSingletonBeanRegistry接口
DefaultSingletonBeanRegistry里有一个addSingleton()方法，会把单例的Bean保存到一个ConcurrentHashMap

// 缓存到一个map里 private final Map< String, Object> singletonObjects = new ConcurrentHashMap(256); protected void addSingleton(String beanName, Object singletonObject) { Map var3 = this.singletonObjects; synchronized(this.singletonObjects) { // 添加单对象到map this.singletonObjects.put(beanName, singletonObject != null ? singletonObject : NULL_OBJECT); this.singletonFactories.remove(beanName); this.earlySingletonObjects.remove(beanName); this.registeredSingletons.add(beanName); } }

DefaultListableBeanFactory 实现类
这个类实现了上面所有的接口

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< beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> < bean id="tank" class="my.Tank"> < /bean> < /beans>

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package my; import org.springframework.beans.factory.support.DefaultListableBeanFactory; import org.springframework.beans.factory.xml.XmlBeanDefinitionReader; import org.springframework.core.io.Resource; import org.springframework.core.io.support.PathMatchingResourcePatternResolver; import java.io.IOException; public class MyTest { public static void main(String[] args) throws IOException { // 创建一个资源加载器 PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(); // 使用ClassPathResource加载配置文件 Resource resource = resolver.getResource("classpath:my.xml"); // 创建一个BeanFactory的对象 DefaultListableBeanFactory factory = new DefaultListableBeanFactory(); XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(factory); reader.loadBeanDefinitions(resource); // 单例的Bean已经缓存到容器中 Tank tank = (Tank)factory.getBean(Tank.class); tank.run(); } } class Tank { public void run() { System.out.println("run..."); } }

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