springboot獲取ApplicationContext的幾種方式

工具類

package com.yzj.learn.common.utils;


import org.springframework.context.ApplicationContext;

public class SpringContextUtil {

    private static ApplicationContext applicationContext;

    public static void setApplicationContext(ApplicationContext context){

        applicationContext=context;
    }

    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    public static Object getBean(String name){
        return applicationContext.getBean(name);
    }

    public static Object getBean(Class<?> requiredType){
        return applicationContext.getBean(requiredType);
    }


}

第一種寫法

@SpringBootApplication
public class ServiceCommonApplication {

    public static void main(String[] args) {

       SpringContextUtil.setApplicationContext( SpringApplication.run(ServiceCommonApplication.class, args));
    }

}

第二種寫法

package com.yzj.learn.common.listeners;

import com.yzj.learn.common.utils.SpringContextUtil;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.*;

public class ContexListener implements ApplicationListener<ApplicationContextEvent> {


    @Override
    public void onApplicationEvent(ApplicationContextEvent event) {

        if (event instanceof ContextRefreshedEvent) {
            SpringContextUtil.setApplicationContext(event.getApplicationContext());
            System.out.println("context 刷新");
        }

        if (event instanceof ContextClosedEvent) {
            System.out.println("context 關閉");
        }

        if (event instanceof ContextStoppedEvent) {

            System.out.println("context 停止");
        }

        if (event instanceof ContextStartedEvent) {

            System.out.println("Context 開啓");
        }

    }
}

@SpringBootApplication
public class ServiceCommonApplication {

    public static void main(String[] args) {

        SpringApplication springApplication=new SpringApplication(ServiceCommonApplication.class);
        springApplication.addListeners(new ContexListener());
        springApplication.run(args);
    }

}

第三種寫法直接注入

@Autowired
ApplicationContext app;