SpringBoot发送Mail

以QQ邮箱为例：使用Spring Boot发送Mail

准备工作

在QQ邮箱设置里开启SMTP服务，并获得授权码，记住授权码备用。

创建Spring Boot项目

通过Spring Initializr创建Spring Boot项目，依赖项包括spring-boot-starter-artemis和spring-boot-starter-mail。

pom文件

<?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>2.3.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>eternal.fire</groupId>
    <artifactId>spring-mail</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-mail</name>
    <description>send email by using spring</description>

    <properties>
        <java.version>14</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-artemis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

配置文件：application.yml

spring:
  mail:
    host: smtp.qq.com
    username: qq号@qq.com
    password: 授权码不是qq密码
    default-encoding: UTF-8
    port: 587
    properties:
      mail:
        smtp:
          auth: true
          starttls:
            enable: true
            required: true

说明：我用排除变量法发现465端口不能用

@SpringBootApplication类

package eternal.fire;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class SpringMailApplication {

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

    @Bean
    CommandLineRunner run(MailService mailService) {
        return args -> mailService.sendEmail("674602921@qq.com", "test");
    }
}

MailService类

package eternal.fire;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Component;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;

@Component
public class MailService {
    JavaMailSender javaMailSender;

    @Autowired
    public MailService(JavaMailSender javaMailSender) {
        this.javaMailSender = javaMailSender;
    }

    public void sendEmail(String email, String message) throws MessagingException {
        MimeMessage mimeMessage = javaMailSender.createMimeMessage();
        MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage);
        mimeMessageHelper.setFrom("发送人的qq@qq.com");
        mimeMessageHelper.setTo(email);
        mimeMessageHelper.setSubject("What's going on?");
        mimeMessageHelper.setText(message);
        javaMailSender.send(mimeMessage);
    }
}

运行

上面的代码里已经在ComandLineRunner里调用了sendEmail方法，可以直接在ide里运行，也可以打包运行。

关于配置

使用Spring Boot而不是Spring MVC的目的不就是因为Spring Boot配置方便吗，Spring Boot帮助我们做了很多事儿，但是我在网上看到好多没有必要的配置。比如，明明已经在application.yml里设置好了一切，但是在MailService类却手动去读取这些配置。再比如spring.mail.protocol的默认值就是smtp，再去设置一遍就有些画蛇添足了。