1.配置專案檔案目錄，我配置的是這樣的：

2：配置pom.xml

參照對比新增包依賴

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

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

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



        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>


        <dependency>
            <groupId>com.vaadin.external.google</groupId>
            <artifactId>android-json</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.testng</groupId>
            <artifactId>testng</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
 

3：配置application.properties檔案

獲取郵箱授權碼的方式可以自行百度。

#郵箱伺服器地址
spring.mail.host=smtp.qq.com
#發件人地址
[email protected]
#郵箱的授權碼
spring.mail.password=xxxxx
spring.mail.default-encoding=utf-8
#發件人
[email protected]

4. 配置MailService和MailServiceImpl檔案

MailService檔案

package com.email.service;

public interface MailService {
    //傳送普通郵件
    void sendSimpleMail(String to,String subject,String content);
    //傳送Html郵件
    void sendHtmlMail(String to,String subject,String content);
    //傳送帶附件的郵件
    void sendAttachmentMail(String to,String subject,String content,String filePath);
}
 

 MailServiceImpl檔案

package com.email.service.impl;

import com.email.service.MailService;
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 org.springframework.stereotype.Service;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.File;


@Service
@Component
public class MailServiceImpl implements MailService {

    @Autowired
    private JavaMailSender mailSender;

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

    @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);
            System.out.println("success");
        }catch (Exception e){
            System.out.println("fail"+e);
        }
    }

    @Override
    public void sendHtmlMail(String to, String subject, String content) {
        MimeMessage message = mailSender.createMimeMessage();
        try {
            MimeMessageHelper helper = new MimeMessageHelper(message, true);   //true表示需要建立一個multipart message
            helper.setFrom(from);
            helper.setTo(to);
            helper.setSubject(subject);
            helper.setText(content, true);
            mailSender.send(message);
            System.out.println("html郵件傳送成功");
        } catch (MessagingException e) {
            System.out.println("傳送html郵件時發生異常！"+e);
        }
    }

    @Override
    public void sendAttachmentMail(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);
            System.out.println("帶附件的郵件已經發送。");
        } catch (MessagingException e) {
            System.out.println("傳送帶附件的郵件時發生異常！"+e);
        }
    }
}
 

 5:MailController檔案

package com.email.controller;


import org.testng.annotations.Test;
import com.email.service.MailService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.thymeleaf.TemplateEngine;

import org.thymeleaf.context.Context;

@RestController
@RequestMapping("/mail")
public class MailController {

    @Autowired
    private MailService mailService;

    @Autowired
    private TemplateEngine templateEngine;


    @RequestMapping("/sendSimpleMail")
    public String sendSimpleMail() {
        String to = "[email protected]";
        String subject = "test html mail";
        String content = "hello, this is html mail！";
        mailService.sendSimpleMail(to, subject, content);
        return "success";
    }

    @RequestMapping("/sendHtmlMail")
    public String  sendHtmlMail() {
        String to = "[email protected]";
        String subject = "test html mail";
        String content = "hello, this is html mail";
        mailService.sendHtmlMail(to, subject, content);
        return "success";
    }


    @Test
    @RequestMapping("/sendAttachmentsMail")
    public String sendAttachmentsMail() {
        String filePath="E:\\11111.txt";
        mailService.sendAttachmentMail("[email protected]", "主題：帶附件的郵件", "有附件，請查收！", filePath);
        return "success";
    }

    @Test
    @RequestMapping("/sendTemplateMail")
    public String sendTemplateMail() {
        //建立郵件正文
        Context context = new Context();
        context.setVariable("user", "1111");
        context.setVariable("web", "tttt");
        context.setVariable("company", "我是一個公司");
        context.setVariable("product","我是一個產品");
        String emailContent = templateEngine.process("emailTemplate", context);
        mailService.sendHtmlMail("[email protected]","主題：這是模板郵件",emailContent);
        return "success";
    }

}

6：emailTemplate.html檔案

<!DOCTYPE html>
<html lang="zh" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<p th:text="'尊敬的 ' + ${user} + '使用者:'"></p>

<p th:text=" '恭喜您註冊成為'+${web}+'網的使用者,同時感謝您對'+${company}+'的關注與支援並歡迎您使用'+${product}+'的產品與服務。'"></p>

</body>
</html>

 7：比較重要的EmailApplication啟動檔案

package com.email;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@SpringBootApplication
@ComponentScan(basePackages = "com.email.*")
public class EmailApplication {

    public static void main(String[] args) {
        SpringApplication.run(EmailApplication.class, args);
        System.out.println("Success");
    }
}

8:執行EmailApplication右擊run。在瀏覽器輸入http://localhost:8080/mail/+對應的方法名即可傳送成功。例如：

即可成功。

======================分割線============================

擴充套件：修改專案為郵件內容可編輯，收件人可自我選擇

1.新建email類

package com.email.email;

public class Email {
    private String to;
    private String object;
    private String content;

    public String getTo() {
        return to;
    }

    public void setTo(String to) {
        this.to = to;
    }

    public String getObject() {
        return object;
    }

    public void setObject(String object) {
        this.object = object;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }

    @Override
    public String toString() {
        return "Email{" +
                "to='" + to + '\'' +
                ", object='" + object + '\'' +
                ", content='" + content + '\'' +
                '}';
    }
}

 2.新建一個方法

@ResponseBody
    @RequestMapping("/sendSimpleMail")
    public String sendSimpleMail(@RequestBody Email email) {
        mailService.sendSimpleMail(email.getTo(),email.getObject(),email.getContent());
        return "success";
    }

3.在templates檔案中新建html檔案 

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8"/>
    <title>第一個HTML頁面</title>
    <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
</head>
<body>

<h1>Hello Spring Boot!!!</h1>


<p th:text="${hello}"></p>

收件人：<input type="text" id="shou">
<br>
標題：<input type="text" id="title">
<br>
內容：<input type="text" id="content">
<br>
附件：<input type="file" id="file">
<br>
<button id="b1">傳送</button>
</body>
<script>
    $(document).ready(function(){
        $("#b1").click(function(){
            $.ajax({
                type:"post",
                url:"/mail/sendSimpleMail",
                dataType : "json",
                data:JSON.stringify({
                    to :$("#shou").val(),
                    object : $("#title").val(),
                    content : $("#content").val()
                }),
                contentType: "application/json",
                success : function () {
                    $("input[name='test']").val("").focus();
                }
            })

        });
    });
</script>
</html>

 4.注：要在application.properties裡配置新的內容。如下：

spring:
thymeleaf:
prefix: classpath:/templates/

 5：注：在html頁面中使用ajax時，data資料要JSON.Stringify（），不然會報錯，如下：

6:附件部分獲取不到檔案地址，如有大佬，看到請指教怎麼獲取到file的地址。感謝！！！