SpringBoot14(监听机制)

一、java监听机制(麻烦、繁琐，不推荐)

二、SpringBoot监听机制

三、代码实现

1-包的定义

2-listener代码块

• 1-MyApplicationContextInitializer

• 

MyApplicationContextInitializer代码块

@Component
public class MyApplicationContextInitializer implements ApplicationContextInitializer {
    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        System.out.println("ApplicationContextInitializer...Run");
    }
}

• 2-MyApplicationRunListener

MyApplicationRunListener代码块

import org.springframework.boot.ConfigurableBootstrapContext;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.SpringApplicationRunListener;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.stereotype.Component;

import java.time.Duration;


public class MyApplicationRunListener implements SpringApplicationRunListener {
    //根据源码写Controller，没有这个是不可以执行下面的代码的
   //下面的参数"SpringApplication application, String[] args"查看springboot的源码
    public MyApplicationRunListener(SpringApplication application, String[] args) {
    }

    @Override
    public void starting(ConfigurableBootstrapContext bootstrapContext) {
        System.out.println("开始。。。");
    }

    @Override
    public void environmentPrepared(ConfigurableBootstrapContext bootstrapContext, ConfigurableEnvironment environment) {
        System.out.println("环境。。。");
    }

    @Override
    public void contextPrepared(ConfigurableApplicationContext context) {
        System.out.println("对象开始准备");
    }

    @Override
    public void contextLoaded(ConfigurableApplicationContext context) {
        System.out.println("加载ing。。。");
    }

    @Override
    public void started(ConfigurableApplicationContext context, Duration timeTaken) {
        this.started(context);
        System.out.println("上下文对象加载完成。。。");
    }

    @Override
    public void running(ConfigurableApplicationContext context) {
        System.out.println("项目启动完成。。");
    }

    @Override
    public void failed(ConfigurableApplicationContext context, Throwable exception) {
        System.out.println("项目启动失败");
    }
}

• 3-MyApplicationRunner

MyApplicationRunner代码块

@Component
public class MyApplicationRunner implements ApplicationRunner{

    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println("ApplicationRunner...Runner");
        System.out.println(Arrays.asList(args.getSourceArgs()));
    }
}

• 4-MyCommandLineRunner

MyCommandLineRunner代码块w

@Component
public class MyCommandLineRunner implements CommandLineRunner {
    @Override
    public void run(String... args) throws Exception {
        System.out.println("CommandLineRunner...Run");
        System.out.println(Arrays.asList(args));
    }
}

四、最后执行结果