详解SpringBoot程序启动时执行初始化代码

package com.stone;

import com.stone.service.ipermissionservice;

import org.springframework.context.applicationlistener;

import org.springframework.context.event.contextrefreshedevent;

/**

  * @author stone yuan

  * @create 2017-12-02 21:54

  * @description

  */

public class applicationstartup implements applicationlistener<contextrefreshedevent> {

   @override

   public void onapplicationevent(contextrefreshedevent contextrefreshedevent) {

     ipermissionservice service = contextrefreshedevent.getapplicationcontext().getbean(ipermissionservice. class );

     service.loaduserpermissionintoredis();

   }

}

package com.stone;

import org.springframework.boot.springapplication;

import org.springframework.boot.autoconfigure.springbootapplication;

@springbootapplication

public class ywythapplication {

   public static void main(string[] args) {

     springapplication springapplication = new springapplication(ywythapplication. class );

     springapplication.addlisteners( new applicationstartup());

     springapplication.run(args);

   }

}

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

import org.springframework.boot.commandlinerunner;

import org.springframework.context.environmentaware;

import org.springframework.core.annotation.order;

import org.springframework.core.env.environment;

import org.springframework.stereotype.component;

import java.util.list;

@component

//如果有多个这样的类时，可以通过order指定执行顺序，数值越小执行优先级越高

@order (value = 0 )

public class initsystemconfig implements commandlinerunner, environmentaware {

   /*

    * 在服务启动后执行，会在@bean实例化之后执行，故如果@bean需要依赖这里的话会出问题

    */

   @override

   public void run(string... args) {

     //这里可以根据数据库返回结果创建一些对象、启动一些线程等

   }

   /*

    * 在systemconfigdao实例化之后、@bean实例化之前执行

    * 常用于读取数据库配置以供其它bean使用

    * environment对象可以获取配置文件的配置，也可以把配置设置到该对象中

    */

   @override

   public void setenvironment(environment environment) {

   }

}