在项目开发中某些场景有必要要用到发动项目后当即履行办法的功能，如咱们需要去初始化数据到redis缓存，或者发动后读取相应的字典配置等，这篇文章首要聊聊完成当即履行的几种办法。

一、CommandLineRunner和ApplicationRunner

这两者的完成办法相同，都是去继承相应的接口然后重写run办法即可，也都是SpringBoot结构所供给应咱们的接口，也是项目中最常用的，比较灵敏，有多个CommandLineRunner或ApplicationRunner完成类时能够经过@Order注解或完成Ordered接口重写getOrder办法完成按指定次序履行

1. CommandLineRunner的完成

import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;
@Component
public class CommandLineRunnerImpl implements CommandLineRunner {
    @Override
    public void run(String... args) throws Exception {
        System.out.println("CommandLineRunnerImpl办法履行");
    }
}

2. ApplicationRunner的完成

import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;
@Component
public class ApplicationRunnerImpl implements ApplicationRunner {
    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println("ApplicationRunner办法履行");
    }

3. 多个CommandLineRunner或ApplicationRunner完成类时指定次序履行

经过@Order注解指定，数字越小越先履行

@Component
@Order(1) //经过order注解指定
public class ApplicationRunnerImpl implements ApplicationRunner {
    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println("ApplicationRunner办法履行");
    }
}

经过完成Ordered接口并重写getOrder办法完成，数字越小越先履行

import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.core.Ordered;
import org.springframework.stereotype.Component;
@Component
public class ApplicationRunnerImpl implements ApplicationRunner, Ordered {
    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println("ApplicationRunner办法履行");
    }
    @Override
    public int getOrder() {
        return 1;
    }
}
  1. CommandLineRunner或ApplicationRunner的不同

这两者的不同其实便是run办法中所接收的参数类型不同，CommandLineRunner是对咱们发动jar包时所传参数不进行处理，原样返回String类型给你，ApplicationRunner是封装成了ApplicationArguments参数，经过这个类型能够更便利的判断某些参数是否存在之类的。

二、JDK所供给的@PostConstruct

@PostConstruct是JDK所供给的注解，使用该注解的办法会在服务器加载Servlet的时候运转。也能够在一个类中写多个办法并增加这个注解。

import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
@Component
public class PostConstructTest {
    @PostConstruct
    public void start() {
        System.out.println("@PostConstruct办法履行");
    }
    @PostConstruct
    public void start01() {
        System.out.println("@PostConstruct1111办法履行");
    }
}

三、其他办法(不常用)

1. ApplicationContextAware

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
@Component
public class ApplicationContextAwareImpl implements ApplicationContextAware {
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        System.out.println("ApplicationContextAwareImpl办法履行");
    }
}

2. ApplicationListener(会履行屡次)

import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;
@Component
public class ApplicationListenerImpl implements ApplicationListener {
    @Override
    public void onApplicationEvent(ApplicationEvent event) {
        System.out.println("ApplicationListenerImpl办法履行");
    }
}

3. InitializingBean

import org.springframework.beans.factory.InitializingBean;
import org.springframework.stereotype.Component;
@Component
public class InitializingBeanImpl implements InitializingBean {
    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("InitializingBeanImpl办法履行");
    }
}

这些办法也都能够完成在发动项目后当即履行，但是不太常用。

以上便是在SpringBoot项目中完成发动项目后当即履行办法的几种办法，如果都我们有协助，记得点赞、保藏哦，谢谢！