在SpringBoot主启动类中获取实例化的Bean

在SpringBoot主启动类中，如果要调⽤某个Bean的⽅法，就需要获取Spring容器中的Bean实例。此时可以通过Spring上下⽂来获取，⽅法如下：

import org.springframework.context.ApplicationContext;

import org.springframework.context.ApplicationContextAware;import org.springframework.stereotype.Component;

@Component

public class ApplicationContextUtil implements ApplicationContextAware { private static ApplicationContext applicationContext = null;

@Override

public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { if(this.applicationContext == null) {

this.applicationContext = applicationContext; } }

public static ApplicationContext getApplicationContext() { return applicationContext; }

public static T getBean(Class clazz) { return getApplicationContext().getBean(clazz); }}

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.ApplicationContext;@SpringBootApplication

public class MainApplication {

public static void main(String[] args) {

SpringApplication.run(MainApplication.class, args);

DemoDao demo = ApplicationContextUtil.getBean(DemoDao.class);　　} }