Spring原理解析

AbstractXmlApplicationContext.class -> AbstractApplicationContext.class -> DefaultResourceLoader.class

1.容器初始化,主要完成了ioc容器建立beanDefinition数据映射。并没有看到ioc容器对bean依赖关系进行注入。

AbstractApplicationContext.refresh()  -> 
	.obtainFreshBeanFactory() -> AbstractRefreshableApplicationContext.refreshBeanFactory() ->
AbstractXmlApplicationContext.loadBeanDefinitions(beanFactory) ->
	.loadBeanDefinitions(beanDefinitionReader) ->
XmlBeanDefinitionReader.loadBeanDefinitions(configResources)	

2.IOC容器依赖注入

AbstractBeanFactory.doGetBean(name,...)  ->
AbstractAutowireCapableBeanFactory.createBean(beanName)

3.Spring生命周期
00–>MyLifeCycleBean 构造函数

----initializeBean -> invokeAwareMethods【setBeanName、setBeanClassLoader、setBeanFactory】-----
01–>BeanNameAware接口被调用了, 获取到的beanName:xmlmyLifeCycleBean
02–>BeanFactoryAware接口被调用了

----initializeBean -> invokeAwareInterfaces【setEnvironment、setEmbeddedValueResolver、setResourceLoader、setApplicationEventPublisher、setMessageSource、setApplicationContext】-----
03–>ApplicationContextAware接口被调用了

----initializeBean -> postProcessBeforeInitialization-----
04–>调用postProcessBeforeInitialization方法, 获取到的beanName: xmlMyLifeCycleBean

----initializeBean -> afterPropertiesSet -----
05–>InitializingBean接口被调用了

06–>myInit方法被调用了

----initializeBean -> postProcessAfterInitialization-----
07–>调用postProcessAfterInitialization, 获取到的beanName: xmlmyLifeCycleBean

08–>bean可以被使用了, beanInfo: MyLifeCycleBean{name=‘张三’, age=25}

MyLifeCycleBeanTest.class

package linag.test.spring;

import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyLifeCycleBeanTest {
    @Before("")
    public void before() {
        System.out.println("---bean生命周期开始---\n");
    }

    @After("")
    public void after() {
        System.out.println("\n---bean生命周期结束---");
    }

    /**
     * 生命周期测试
     */
    @Test
    public void testDefaultConstructor() {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        MyLifeCycleBean myLifeCycleBean = applicationContext.getBean(MyLifeCycleBean.class);
        System.out.println("08-->bean可以被使用了, beanInfo: " + myLifeCycleBean.toString());
        ((ClassPathXmlApplicationContext) applicationContext).destroy();
    }
}

MyBeanPostProcessor.class

package linag.test.spring;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.stereotype.Component;

@Component
public class MyBeanPostProcessor implements BeanPostProcessor {

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        if(!(bean instanceof  MyLifeCycleBean)) {
            return bean;
        }
        System.out.println("04-->调用postProcessBeforeInitialization方法, 获取到的beanName: " + beanName);
        ((MyLifeCycleBean) bean).setName("李四");
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        if(!(bean instanceof  MyLifeCycleBean)) {
            return bean;
        }
        System.out.println("07-->调用postProcessAfterInitialization, 获取到的beanName: " + beanName);
        ((MyLifeCycleBean) bean).setAge(30);
        return bean;
    }

}

MyLifeCycleBean.class

package linag.test.spring;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.*;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;


public class MyLifeCycleBean implements BeanNameAware, BeanFactoryAware, ApplicationContextAware, InitializingBean,
    DisposableBean {

    // 姓名
    private String name;
    // 年龄
    private int age;

    public MyLifeCycleBean() {
        System.out.println("00-->MyLifeCycleBean 构造函数");
    }

    @Override
    public void setBeanName(String name) {
        System.out.println("01-->BeanNameAware接口被调用了, 获取到的beanName:" + name);
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        System.out.println("02-->BeanFactoryAware接口被调用了");
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        System.out.println("03-->ApplicationContextAware接口被调用了");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("05-->InitializingBean接口被调用了");

    }

    public void myInit() {
        System.out.println("06-->myInit方法被调用了");
    }

    @Override
    public void destroy() throws Exception {
        System.out.println("09-->DisposableBean接口被调用了");
    }

    public void myDestroy() {
        System.out.println("10-->自定义destroy-method方法被调动了");
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "MyLifeCycleBean{" + "name='" + name + '\'' + ", age=" + age + '}';
    }
}

applicationContext.xml

   <bean name="xmlmyLifeCycleBean" class="linag.test.spring.MyLifeCycleBean" destroy-method="myDestroy"
          init-method="myInit">
        <property name="name" value="张三"/>
        <property name="age" value="25"/>
    </bean>