<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.7</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

package com.example.demo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import java.util.concurrent.Executor;


/**
 * 線程池參數(shù)配置
 **/
@EnableAsync
@Configuration
public class TaskPoolConfig {
    /**
     * 自定義線程池
     **/
    @Bean
    public Executor taskExecutor() {
        //返回可用處理器的Java虛擬機(jī)的數(shù)量 12
        int i = Runtime.getRuntime().availableProcessors();
        System.out.println("系統(tǒng)最大線程數(shù)  ： " + i);

        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        //核心線程池大小
        executor.setCorePoolSize(16);
        //最大線程數(shù)
        executor.setMaxPoolSize(20);
        //配置隊(duì)列容量，默認(rèn)值為Integer.MAX_VALUE
        executor.setQueueCapacity(99999);
        //活躍時(shí)間
        executor.setKeepAliveSeconds(60);
        //線程名字前綴
        executor.setThreadNamePrefix("asyncServiceExecutor -");
        //設(shè)置此執(zhí)行程序應(yīng)該在關(guān)閉時(shí)阻止的最大秒數(shù)，以便在容器的其余部分繼續(xù)關(guān)閉之前等待剩余的任務(wù)完成他們的執(zhí)行
        executor.setAwaitTerminationSeconds(60);
        //等待所有的任務(wù)結(jié)束后再關(guān)閉線程池
        executor.setWaitForTasksToCompleteOnShutdown(true);

        return executor;
    }
}

package com.example.demo.entity;

import lombok.Data;

@Data
public class EmailDto {
    private String email;
    private String subject;
    private String content;
}

package com.example.demo.event;

import com.example.demo.entity.EmailDto;
import org.springframework.context.ApplicationEvent;

/**
 * 自定義事件
 */
public class SendEmailEvent extends ApplicationEvent {
    private EmailDto emailDto;

    public SendEmailEvent(EmailDto emailDto) {
        super(emailDto);
        this.emailDto = emailDto;
    }

    public EmailDto getEmailDto() {
        return this.emailDto;
    }
}

package com.example.demo.listener;

import com.example.demo.entity.EmailDto;
import com.example.demo.event.SendEmailEvent;
import com.example.demo.service.SendEmailService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationListener;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;

/**
 * 事件監(jiān)聽(tīng)器
 */
@Component
public class SendEmailListener implements ApplicationListener<SendEmailEvent> {
    @Autowired
    private SendEmailService sendEmailService;

    @Async
    @Override
    public void onApplicationEvent(SendEmailEvent event) {
        EmailDto emailDto = event.getEmailDto();
        this.sendEmailService.sendEmail(emailDto);
    }
}

package com.example.demo.service;

import com.example.demo.entity.EmailDto;

public interface SendEmailService {
    void sendEmail(EmailDto emailDto);
}

package com.example.demo.service.impl;

import com.example.demo.entity.EmailDto;
import com.example.demo.service.SendEmailService;
import org.springframework.stereotype.Service;

@Service
public class SendEmailServiceImpl implements SendEmailService {
    @Override
    public void sendEmail(EmailDto emailDto) {
        try {
            // 模擬耗時(shí)3秒
            Thread.sleep(3 * 1000);
        } catch (Exception e) {
            System.out.println("Email發(fā)送異常");
        }

        System.out.println("Email發(fā)送成功 " + emailDto);
    }
}

package com.example.demo.controller;

import com.example.demo.entity.EmailDto;
import com.example.demo.event.SendEmailEvent;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class IndexController {
    @Autowired
    private ApplicationEventPublisher publisher;

    @GetMapping("/sendEmail")
    public String sendEmail() {
        EmailDto emailDto = new EmailDto();
        emailDto.setEmail("tom@qq.com");
        emailDto.setSubject("郵件標(biāo)題");
        emailDto.setContent("郵件內(nèi)容");

        // 發(fā)布事件
        publisher.publishEvent(new SendEmailEvent(emailDto));
        return "success";
    }
}