BeanPostProcessor
在Bean的初始化阶段有前置和后置方法,这个方法是通过BeanPostProcessor来管理的,下面我们对原有的项目结构做小小的更改。
对启动类作出修改,先检查有没有BeanPostProcessor的实现类,有的话就使用,没有就使用默认的。
// 2.判断是否是postProcessor
for (String name : allJavaFile) {
Class<?> clazz = beanScanner.getClazz(name);
if (beanScanner.isImplBeanPostProcessor(clazz)){
Object bean = beanFactory.createBean(clazz);
beanPostProcessor = (BeanPostProcessor) bean;
beanFactory.getCreatedBeanSet().add(bean);
}
}
if (beanPostProcessor == null){
beanPostProcessor = new DefaultBeanPostProcessor();
}
第二次循环先检查是不是postProcessor,是的话就跳过就行
// 3.判断是否有Component
for (String name : allJavaFile) {
if (beanScanner.isComponent(name)) {
// 4.是Component就开始bean的生命周期
Class<?> clazz = beanScanner.getClazz(name);
boolean flag = false;
for (Object o : beanFactory.getCreatedBeanSet()) {
if (o.getClass().equals(clazz)) {
flag = true;
break;
}
}
if (flag){
continue;
}
Object bean = beanFactory.createBean(clazz);
String beanName = beanFactory.parseBeanName(bean);
// 查看@Value注解
// 1.找到所有@Value的字段
......
最后执行这些代码
// init
beanFactory.getBeanMap().put(beanName,bean);
beanPostProcessor.postProcessBeforeInitialization(bean);
beanFactory.doInitialization(bean,beanScanner);
beanPostProcessor.postProcessAfterInitialization(bean);
BeanFactory
这些方法都大差不差,思路就是找注解/接口,去invoke执行方法文章来源:https://www.toymoban.com/news/detail-691666.html
/**
* 进行初始化
*
* @param bean 豆
* @throws Exception 例外
*/
public void doInitialization(Object bean, BeanScanner beanScanner) throws Exception {
// @PostConstruct
List<Method> postConstruct = beanScanner.getPostConstruct(bean);
for (Method method : postConstruct) {
method.invoke(bean);
}
// InitializingBean
if (beanScanner.isImplInitializing(bean)) {
doInitialize(bean);
}
}
测试类
package com.ez4sterben.spring.test;
import com.ez4sterben.spring.ioc.annotation.Component;
import com.ez4sterben.spring.ioc.factory.BeanPostProcessor;
/**
* 测试bean后处理器
*
* @author ez4sterben
* @date 2023/09/02
*/
@Component
public class TestBeanPostProcessor implements BeanPostProcessor {
@Override
public Object postProcessBeforeInitialization(Object bean) {
System.out.println("postProcessBeforeInitialization");
return BeanPostProcessor.super.postProcessBeforeInitialization(bean);
}
@Override
public Object postProcessAfterInitialization(Object bean) {
System.out.println("postProcessAfterInitialization");
return BeanPostProcessor.super.postProcessAfterInitialization(bean);
}
}
package com.ez4sterben.spring.test;
import com.ez4sterben.spring.ioc.annotation.Component;
import com.ez4sterben.spring.ioc.annotation.Value;
import com.ez4sterben.spring.ioc.context.ApplicationContext;
import com.ez4sterben.spring.ioc.factory.BeanPostProcessor;
import com.ez4sterben.spring.ioc.factory.InitializingBean;
import com.ez4sterben.spring.ioc.factory.aware.ApplicationContextAware;
import com.ez4sterben.spring.ioc.factory.aware.BeanFactoryAware;
import com.ez4sterben.spring.ioc.factory.aware.BeanNameAware;
import com.ez4sterben.spring.ioc.factory.support.BeanFactory;
import lombok.Data;
import javax.annotation.PostConstruct;
/**
* 测试组件
*
* @author ez4sterben
* @date 2023/09/01
*/
@Component
@Data
public class TestComponent implements BeanNameAware, BeanFactoryAware, ApplicationContextAware, InitializingBean {
@Value("ez4sterben")
private String name;
private String age;
@Override
public void setBeanName(String beanName) {
System.out.println(beanName);
}
@PostConstruct
public void init(){
System.out.println("postConstruct");
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) {
System.out.println(applicationContext.getBeanMap().toString());
}
@Override
public void setBeanFactory(BeanFactory beanFactory) {
System.out.println(beanFactory.getBeanMap().toString());
}
@Override
public void afterPropertiesSet() {
System.out.println("afterPropertiesSet");
}
}
结果
文章来源地址https://www.toymoban.com/news/detail-691666.html
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