有些其他的檔案 如 Devtools 和 mail元件等可以在下面勾選，也可以自己手動新增

新增完點選生成，會下載一個壓縮包，匯入到 idea即可

正式開始

1、如果剛才沒勾選 mail 則需要新增依賴

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

2、在application.properties中新增郵箱配置（注意 配置完畢後把後面的註釋去掉，否則會提示連線不上的錯誤）

     把使用者名稱和密碼改成自己郵箱的使用者名稱和密碼 伺服器地址變成郵箱傳送伺服器的地址 如：smtp.126.com

spring.mail.host=smtp.qiye.163.com //郵箱伺服器地址
[email protected] //使用者名稱
spring.mail.password=xxyyooo    //密碼
spring.mail.default-encoding=UTF-8

[email protected]  //以誰來發送郵件
 

 3、編寫介面和實現類

       介面：

package com.emailtest.service;

/**
 * Created by admin 
 *
 */
public interface MailService {

    public void sendSimpleMail(String to, String subject, String content);

    public void sendHtmlMail(String to, String subject, String content);

    public void sendAttachmentsMail(String to, String subject, String content, String filePath);

    public void sendInlineResourceMail(String to, String subject, String content, String rscPath, String rscId);

}
 

       實現類：

package com.emailtest.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.FileSystemResource;
import org.springframework.mail.SimpleMailMessage;
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;
import java.io.File;

/**
 * Created by admin 
 *
 */
@Component
public class MailServiceImpl implements MailService{

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private JavaMailSender mailSender;

    @Value("${mail.fromMail.addr}")
    private String from;

    /**
     * 傳送文字郵件
     * @param to
     * @param subject
     * @param content
     */
    @Override
    public void sendSimpleMail(String to, String subject, String content) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject(subject);
        message.setText(content);

        try {
            mailSender.send(message);
            logger.info("簡單郵件已經發送。");
        } catch (Exception e) {
            logger.error("傳送簡單郵件時發生異常！", e);
        }

    }

    /**
     * 傳送html郵件
     * @param to
     * @param subject
     * @param content
     */
    @Override
    public void sendHtmlMail(String to, String subject, String content) {
        MimeMessage message = mailSender.createMimeMessage();

        try {
            //true表示需要建立一個multipart message
            MimeMessageHelper helper = new MimeMessageHelper(message, true);
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);

            mailSender.send(message);
            logger.info("html郵件傳送成功");
        } catch (MessagingException e) {
            logger.error("傳送html郵件時發生異常！", e);
        }
    }


    /**
     * 傳送帶附件的郵件
     * @param to
     * @param subject
     * @param content
     * @param filePath
     */
    public void sendAttachmentsMail(String to, String subject, String content, String filePath){
        MimeMessage message = mailSender.createMimeMessage();

        try {
            MimeMessageHelper helper = new MimeMessageHelper(message, true);
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);

            FileSystemResource file = new FileSystemResource(new File(filePath));
            String fileName = filePath.substring(filePath.lastIndexOf(File.separator));
            helper.addAttachment(fileName, file);
            //helper.addAttachment("test"+fileName, file);

            mailSender.send(message);
            logger.info("帶附件的郵件已經發送。");
        } catch (MessagingException e) {
            logger.error("傳送帶附件的郵件時發生異常！", e);
        }
    }


    /**
     * 傳送正文中有靜態資源（圖片）的郵件
     * @param to
     * @param subject
     * @param content
     * @param rscPath
     * @param rscId
     */
    public void sendInlineResourceMail(String to, String subject, String content, String rscPath, String rscId){
        MimeMessage message = mailSender.createMimeMessage();

        try {
            MimeMessageHelper helper = new MimeMessageHelper(message, true);
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);

            FileSystemResource res = new FileSystemResource(new File(rscPath));
            helper.addInline(rscId, res);

            mailSender.send(message);
            logger.info("嵌入靜態資源的郵件已經發送。");
        } catch (MessagingException e) {
            logger.error("傳送嵌入靜態資源的郵件時發生異常！", e);
        }
    }
}

 4、在src/main/resources 下建立資料夾templates 存放模板檔案emailTemplate.html

emailTemplate.html檔案的內容如下

<!DOCTYPE html>
<html lang="zh" xmlns:th="http://www.thymeleaf.org">
    <head>
        <meta charset="UTF-8"/>
        <title>Title</title>
    </head>
    <body>
        您好,這是驗證郵件,請點選下面的連結完成驗證,<br/>
        <a href="#" th:href="@{ http://www.aaabbb.com/ccc/{id}(id=${id}) }">啟用賬號</a>
    </body>
</html>

5、建立測試類EmailtestApplicationTests，用junit單元測試即可收到郵件，完整程式碼如下：

     提示：如果需要測試，請把郵箱變成自己的，謝謝

package com.emailtest.emailtest;

import com.emailtest.service.MailService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.Context;

/**
 * Created by admin
 *
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class EmailtestApplicationTests {

	@Autowired
	private MailService mailService;

	@Autowired
	private TemplateEngine templateEngine;

	@Test
	public void testSimpleMail() throws Exception {
		mailService.sendSimpleMail("[email protected]","test simple mail"," hello this is simple mail");
	}

	@Test
	public void testHtmlMail() throws Exception {
		String content="<html>\n" +
				"<body>\n" +
				"    <h3>hello world ! 這是一封html郵件!</h3>\n" +
				"</body>\n" +
				"</html>";
		mailService.sendHtmlMail("[email protected]","test simple mail",content);
	}

	@Test
	public void sendAttachmentsMail() {
		String filePath="C:\\Users\\Administrator\\Pictures\\Saved Pictures\\timg (1).jpg";
		mailService.sendAttachmentsMail("[email protected]", "主題：帶附件的郵件", "有附件，請查收！", filePath);
	}


	@Test
	public void sendInlineResourceMail() {
		String rscId = "C:\\Users\\Administrator\\Pictures\\Saved Pictures\\timg (1).jpg";
		String content="<html><body>這是有圖片的郵件：<img src=\'cid:" + rscId + "\' ></body></html>";
		String imgPath = "C:\\Users\\Administrator\\Pictures\\Saved Pictures\\timg (1).jpg";

		mailService.sendInlineResourceMail("[email protected]", "主題：這是有圖片的郵件", content, imgPath, rscId);
	}


	@Test
	public void sendTemplateMail() {
		//建立郵件正文
		Context context = new Context();
		context.setVariable("id", "006");
		String emailContent = templateEngine.process("emailTemplate", context);

		mailService.sendHtmlMail("[email protected]","主題：這是模板郵件",emailContent);
	}
}

是不是很簡單？