- invokeInitMethods
-
- invokeCustomInitMethod自定义的初始方法
-
- getInterfaceMethodIfPossible尝试获取接口方法
- applyBeanPostProcessorsAfterInitialization初始化之后处理
-
- PostProcessorRegistrationDelegate内部类BeanPostProcessorChecker的postProcessAfterInitialization
- ApplicationListenerDetector的postProcessAfterInitialization
invokeInitMethods
前面讲一初始化前做的处理，今天继续。
这个方法就是我们如果实现了InitializingBean接口的话，就可能要调用afterPropertiesSet方法，其实就是个回调，告诉你属性设置好了。当然后面也有自定义的初始化方法invokeCustomInitMethod。
protected void invokeInitMethods(String beanName, final Object bean, @Nullable RootBeanDefinition mbd)
throws Throwable {
//实现InitializingBean接口的
boolean isInitializingBean = (bean instanceof InitializingBean);
if (isInitializingBean && (mbd == null || !mbd.isExternallyManagedInitMethod("afterPropertiesSet"))) {
if (logger.isTraceEnabled()) {
logger.trace("Invoking afterPropertiesSet() on bean with name '" + beanName + "'");
}
if (System.getSecurityManager() != null) {
try {
AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () -> {
((InitializingBean) bean).afterPropertiesSet();
return null;
}, getAccessControlContext());
}
catch (PrivilegedActionException pae) {
throw pae.getException();
}
}
else {
((InitializingBean) bean).afterPropertiesSet();
}
}
//初始化方法，比如xml配置的
if (mbd != null && bean.getClass() != NullBean.class) {
String initMethodName = mbd.getInitMethodName();
if (StringUtils.hasLength(initMethodName) &&
!(isInitializingBean && "afterPropertiesSet".equals(initMethodName)) &&
!mbd.isExternallyManagedInitMethod(initMethodName)) {
invokeCustomInitMethod(beanName, bean, mbd);
}
}
}
invokeCustomInitMethod自定义的初始方法
获取bean的自定义初始化方法，如果自身或者父类是接口类型的话，就反射出接口方法来，最后调用。
protected void invokeCustomInitMethod(String beanName, final Object bean, RootBeanDefinition mbd)
throws Throwable {
String initMethodName = mbd.getInitMethodName();
Assert.state(initMethodName != null, "No init method set");
Method initMethod = (mbd.isNonPublicAccessAllowed() ?
BeanUtils.findMethod(bean.getClass(), initMethodName) :
ClassUtils.getMethodIfAvailable(bean.getClass(), initMethodName));
if (initMethod == null) {
if (mbd.isEnforceInitMethod()) {
throw new BeanDefinitionValidationException("Could not find an init method named '" +
initMethodName + "' on bean with name '" + beanName + "'");
}
else {
if (logger.isTraceEnabled()) {
logger.trace("No default init method named '" + initMethodName +
"' found on bean with name '" + beanName + "'");
}
// Ignore non-existent default lifecycle methods.
return;
}
}
if (logger.isTraceEnabled()) {
logger.trace("Invoking init method '" + initMethodName + "' on bean with name '" + beanName + "'");
}
Method methodToInvoke = ClassUtils.getInterfaceMethodIfPossible(initMethod);
if (System.getSecurityManager() != null) {
AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
ReflectionUtils.makeAccessible(methodToInvoke);
return null;
});
try {
AccessController.doPrivileged((PrivilegedExceptionAction<Object>) () ->
methodToInvoke.invoke(bean), getAccessControlContext());
}
catch (PrivilegedActionException pae) {
InvocationTargetException ex = (InvocationTargetException) pae.getException();
throw ex.getTargetException();
}
}
else {
try {
ReflectionUtils.makeAccessible(methodToInvoke);
methodToInvoke.invoke(bean);
}
catch (InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}
getInterfaceMethodIfPossible尝试获取接口方法
尝试从自身或者父类获取接口方法。
public static Method getInterfaceMethodIfPossible(Method method) {
if (Modifier.isPublic(method.getModifiers()) && !method.getDeclaringClass().isInterface()) {
Class<?> current = method.getDeclaringClass();
while (current != null && current != Object.class) {
Class<?>[] ifcs = current.getInterfaces();
for (Class<?> ifc : ifcs) {
try {
return ifc.getMethod(method.getName(), method.getParameterTypes());
}
catch (NoSuchMethodException ex) {
// ignore
}
}
current = current.getSuperclass();
}
}
return method;
}
applyBeanPostProcessorsAfterInitialization初始化之后处理
跟初始化之前处理差不多。
@Override
public Object applyBeanPostProcessorsAfterInitialization(Object existingBean, String beanName)
throws BeansException {
Object result = existingBean;
for (BeanPostProcessor processor : getBeanPostProcessors()) {
Object current = processor.postProcessAfterInitialization(result, beanName);
if (current == null) {
return result;
}
result = current;
}
return result;
}
PostProcessorRegistrationDelegate内部类BeanPostProcessorChecker的postProcessAfterInitialization
没干瘪的，就是打印信息。
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) {
if (!(bean instanceof BeanPostProcessor) && !isInfrastructureBean(beanName) &&
this.beanFactory.getBeanPostProcessorCount() < this.beanPostProcessorTargetCount) {
if (logger.isInfoEnabled()) {
logger.info("Bean '" + beanName + "' of type [" + bean.getClass().getName() +
"] is not eligible for getting processed by all BeanPostProcessors " +
"(for example: not eligible for auto-proxying)");
}
}
return bean;
}
ApplicationListenerDetector的postProcessAfterInitialization
将我们自定义的单例类作为监听器添加到applicationEventMulticaster里。
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) {
if (bean instanceof ApplicationListener) {
// potentially not detected as a listener by getBeanNamesForType retrieval
Boolean flag = this.singletonNames.get(beanName);
if (Boolean.TRUE.equals(flag)) {
// singleton bean (top-level or inner): register on the fly
this.applicationContext.addApplicationListener((ApplicationListener<?>) bean);
}
else if (Boolean.FALSE.equals(flag)) {
if (logger.isWarnEnabled() && !this.applicationContext.containsBean(beanName)) {
// inner bean with other scope - can't reliably process events
logger.warn("Inner bean '" + beanName + "' implements ApplicationListener interface " +
"but is not reachable for event multicasting by its containing ApplicationContext " +
"because it does not have singleton scope. Only top-level listener beans are allowed " +
"to be of non-singleton scope.");
}
this.singletonNames.remove(beanName);
}
}
return bean;
}
至此初始化基本完成了。
好了，今天就到这里了，希望对学习理解有帮助，大神看见勿喷，仅为自己的学习理解，能力有限，请多包涵。