spring中bean初始化顺序

spring bean 初始化的流程如下：

初始化顺序演示程序

pom文件

	4.0.0
	springBean
	
		
			org.springframework.boot
			spring-boot-starter-web
			2.2.2.RELEASE
		

		
			org.springframework.boot
			spring-boot-starter-actuator
			2.2.2.RELEASE
		

		
			org.springframework.boot
			spring-boot-devtools
			runtime
			true
			2.2.2.RELEASE
		

		
			org.springframework.boot
			spring-boot-starter-test
			2.2.2.RELEASE
			test
		
	

启动类

package springBean;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MainBean {
	public static void main(String[] args) throws Exception {
		SpringApplication.run(MainBean.class, args);
	}
}

Bean配置文件

package springBean.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import springBean.bean.BeanInitOrder;

@Configuration
public class BeanConfig {
	
	@Bean(name = {"beanInitOrder"},initMethod = "initMethod" ,destroyMethod = "destroyMethod")
    public BeanInitOrder getBeanInitOrder(){
        return new BeanInitOrder();
    }
	
}

Bean初始化前置执行配置文件（对所有bean通用）

package springBean.config;

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

@Component
public class MyBeanPostProcessor implements BeanPostProcessor{
	/* 
	 * 本方法一定要返回bean对象
	 */
	@Override
	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
		if("beanInitOrder".equals(beanName)) {			
			System.out.println(beanName+"执行对象初始化前-前置处理");
		}
		return bean;
	}

	/* 
	 * 本方法一定要返回bean对象
	 */
	@Override
	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
		if("beanInitOrder".equals(beanName)) {
			System.out.println(beanName+"执行对象初始化后-后置处理");
		}
		return bean;
	}	
}

Bean文件

package springBean.bean;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

import org.springframework.beans.factory.annotation.Autowired;

public class BeanInitOrder {
	@Autowired
	public BeanInitOrder2 order;
	
	public BeanInitOrder() {
		System.out.println("bean对象实例化-构造方法");
	}
	@PostConstruct
	public void init() {
		System.out.println("Bean-PostConstruct");
	}
	@PreDestroy
	public void preDestroy() {
		System.out.println("Bean-preDestroy");
	}
	
	public void initMethod() {
		System.out.println("initMethod");
	}
	public void destroyMethod() {
		System.out.println("destroyMethod");
	}
	
}

执行打印结果