简话bean加载

<!--no-lazy-init   scope=singleton-->
<bean class="com.lios.service.test.LiosTestA" id="liosTestA"/>
<bean class="com.lios.service.test.LiosTestB" id="liosTestB"/>
<bean class="com.lios.service.test.LiosServiceServiceImpl" id="liosServiceService"/>

ClassPathXmlApplicationContext resource = new ClassPathXmlApplicationContext("app.xml");
BeanFactory beanFactory = resource.getBeanFactory();
LiosServiceServiceImpl liosServiceService = (LiosServiceServiceImpl) beanFactory.getBean("liosServiceService");
liosServiceService.t();

@Service
public class LiosServiceServiceImpl {
    private int i = 1;
    @Autowired
    LiosTestA liosTestA;
    public void t(){
        try {
            liosTestA.testA();
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("===========>");
    }
}

@Service
public class LiosTestA {
    @Autowired
    LiosTestB liosTestB;
    public void testA(){
        liosTestB.testB();
    }
}

// Instantiate all remaining (non-lazy-init) singletons.
finishBeanFactoryInitialization(beanFactory);

// Instantiate all remaining (non-lazy-init) singletons.
beanFactory.preInstantiateSingletons();

@Override
public Object getBean(String name) throws BeansException {
    return doGetBean(name, null, null, false);
}

//获取beanName
final String beanName = transformedBeanName(name);
//从缓存里获取bean,第一次时毫无疑问,sharedInstance为null
Object sharedInstance = getSingleton(beanName);
//获取RootBeanDefinition,其实用BeanDefinition初始化
final RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);
创建bean
createBean(beanName, mbd, args)

instanceWrapper = createBeanInstance(beanName, mbd, args);

// Make sure bean class is actually resolved at this point.
Class<?> beanClass = resolveBeanClass(mbd, beanName);
//.... 后面省略

/**
 * Return the bean instance wrapped by this object, if any.
 * @return the bean instance, or {@code null} if none set
 */
Object getWrappedInstance();

// Initialize the bean instance.
Object exposedObject = bean;
try {
    //初始化bean属性的值
    populateBean(beanName, mbd, instanceWrapper);
    if (exposedObject != null) {
        exposedObject = initializeBean(beanName, exposedObject, mbd);
    }
}

for (BeanPostProcessor bp : getBeanPostProcessors()) {
if (bp instanceof InstantiationAwareBeanPostProcessor) {
    InstantiationAwareBeanPostProcessor ibp = (InstantiationAwareBeanPostProcessor) bp;
    pvs = ibp.postProcessPropertyValues(pvs, filteredPds, bw.getWrappedInstance(), beanName);
    if (pvs == null) {
        return;
    }
  }
}

InjectionMetadata metadata = findResourceMetadata(beanName, bean.getClass(), pvs);
metadata.inject(bean, beanName, pvs);

value = beanFactory.resolveDependency(desc, beanName, autowiredBeanNames, typeConverter);

result = doResolveDependency(descriptor, beanName, autowiredBeanNames, typeConverter);

Map<String, Object> matchingBeans = findAutowireCandidates(beanName, type, descriptor);

result.put(candidateName, getBean(candidateName));

if (value != null) {
ReflectionUtils.makeAccessible(field);
field.set(bean, value);
}

initializeBean(beanName, exposedObject, mbd);

boolean isInitializingBean = (bean instanceof InitializingBean);
        if (isInitializingBean && (mbd == null || !mbd.isExternallyManagedInitMethod("afterPropertiesSet"))) {
            if (logger.isDebugEnabled()) {
                logger.debug("Invoking afterPropertiesSet() on bean with name '" + beanName + "'");
            }
            if (System.getSecurityManager() != null) {
                try {
                    AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
                        @Override
                        public Object run() throws Exception {
                            ((InitializingBean) bean).afterPropertiesSet();
                            return null;
                        }
                    }, getAccessControlContext());
                }
                catch (PrivilegedActionException pae) {
                    throw pae.getException();
                }
            }
            else {
                ((InitializingBean) bean).afterPropertiesSet();
            }
        }