springboot2 整合發送郵件的功能

1，你需要申請一個郵箱

1，申請一個 163 的郵箱並登入，這個很簡單

2，如下圖進入設置

3，確定下圖中的選項為開啟狀態，切記，開啟功能的時候，系統會給你分配一個授權碼，只會顯示一次，一定要記錄下來

2，SpringBoot 框架整合

1，pom.xml

<!-- FreeMarker 模板引擎，用於生成郵件內容 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>
<!-- 郵件發送的依賴 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

2，application.yml

spring:
  freemarker:
    enabled: true
    cache: true
    content-type: text/html
    charset: UTF-8
    check-template-location: true
    template-loader-path: classpath:templates
    # prefix:
    suffix: .ftl
    prefer-file-system-access: true
    allow-request-override: false
    allow-session-override: false
    expose-request-attributes: false
    expose-session-attributes: false
    expose-spring-macro-helpers: false
  mail:
    host: smtp.163.com
    username: 你的郵箱賬號
    password: 授權碼（注意，不是郵箱的密碼）

3，封裝一個文件類，在發送附件和靜態資源的時候使用

package com.hwq.common.vo;

import lombok.Getter;
import lombok.Setter;

import java.io.File;

@Getter
@Setter
public class MailFileVo {

    /**
     * 1，當作為靜態資源時，代表資源的唯一標識，可以插入到 html 內容中，如 img 標簽的 src 屬性
     * 2，當作為附件時，作為附件的名稱
     */
    private String name;

    /**
     * 文件對象，可以是附件也可以是靜態資源
     */
    private File file;

}

4，封裝一個發送郵件的類，

package com.hwq.web.server.service;

import com.hwq.common.vo.MailFileVo;
import org.apache.commons.collections4.CollectionUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Service;

import javax.mail.Address;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.List;

@Service
public class MailService {

    @Autowired
    private JavaMailSender mailSender;

    @Value("${spring.mail.username}")
    private String fromMail;

    /**
     * 發送郵件的方法
     *
     * 三種收件人模式的解釋
     * 1，Message.RecipientType.TO  直接接收人
     * 2，Message.RecipientType.CC  明抄送收件人
     * 3，Message.RecipientType.BCc 暗抄送收件人（不會 被直接收件人 和 明抄送收件人 看見的收件人）
     *
     * @param toAddr  收件人的 郵件地址
     * @param ccAddr  抄送人的 郵件地址
     * @param subject 郵件標題
     * @param html    郵件內容
     * @param srcVos  靜態資源類
     * @param athVos  附件資源類
     */
    public void sendMail(String[] toAddr, String[] ccAddr, String subject, String html, List<MailFileVo> srcVos, List<MailFileVo> athVos) {
        try {
            MimeMessage message = mailSender.createMimeMessage();
            MimeMessageHelper helper = new MimeMessageHelper(message, true);
            helper.setFrom(fromMail);
            helper.setSubject(subject); 
            helper.setText(html, true); 
            if (toAddr != null && toAddr.length > 0) {
                Address[] addresses = new Address[toAddr.length];
                for (int i = 0; i < toAddr.length; i ++) {
                    addresses[i] = new InternetAddress(toAddr[i]);
                }
                message.setRecipients(Message.RecipientType.TO, addresses);
            }
            if (ccAddr != null && ccAddr.length > 0) {
                Address[] addresses = new Address[ccAddr.length];
                for (int i = 0; i < ccAddr.length; i ++) {
                    addresses[i] = new InternetAddress(ccAddr[i]);
                }
                message.setRecipients(Message.RecipientType.CC, addresses);
            }
            if (CollectionUtils.isNotEmpty(srcVos)) {
                for (MailFileVo srcVo : srcVos) {
                    helper.addInline(srcVo.getName(), srcVo.getFile());
                }
            }
            if (CollectionUtils.isNotEmpty(athVos)) {
                for (MailFileVo athVo : athVos) {
                    helper.addAttachment(athVo.getName(), athVo.getFile());
                }
            }
            mailSender.send(message);
        } catch (MessagingException ex) {
            ex.printStackTrace();
            throw new RuntimeException(ex.getMessage());
        }
    }

}

5，准備一個郵件模板，mail.ftl

<style type="text/css">
    .mail-table {
        width: 100%;
        border-top: 1px solid #333;
        border-left: 1px solid #333;
        border-collapse: collapse;
        border-spacing: 0;
    }
    .mail-table tr {

    }
    .mail-table th {
        background: rgb(255, 204, 204);
        height: 40px;
        border-bottom: 1px solid #333;
        border-right: 1px solid #333;
    }
    .mail-table td {
        height: 36px;
        text-indent: 14px;
        border-bottom: 1px solid #333;
        border-right: 1px solid #333;
    }
</style>

<h3>${title}</h3>
<table class="mail-table">
    <tr>
        <th>序號</th>
        <th>賬號</th>
        <th>昵稱</th>
    </tr>
    <#list users as user>
    <tr>
        <td>${user_index + 1}</td>
        <td>${user.account}</td>
        <td>${user.nickname}</td>
    </tr>
    </#list>
</table>
<!-- 圖片地址固定為 cid:封裝的 MailFileVo 的 name 屬性 -->
<img src="cid:battle-field" />

6，測試，寫一個控制器發送郵件

package com.hwq.web.server.controller;

import com.hwq.common.data.entity.User;
import com.hwq.common.util.HttpUtil;
import com.hwq.common.vo.MailFileVo;
import com.hwq.web.server.service.MailService;
import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.ResponseEntity;
import org.springframework.ui.freemarker.FreeMarkerTemplateUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

    @Autowired
    private MailService mailService;
    @Autowired
    private Configuration configuration;

    @Value("${file.save.location}")
    private String rootPath; // 這是你靜態資源存放的根路徑，從配置文件讀取

    @RequestMapping("/send")
    public ResponseEntity<Object> sendSimpleMail() throws IOException, TemplateException {
        Template template = configuration.getTemplate("mail.ftl");
        Map<String, Object> model = new HashMap<>();
        List<User> users = new ArrayList<>();
        for (int i = 0; i < 10; i ++) {
            User user = new User();
            user.setAccount("102020200" + i);
            user.setNickname("張三李四" + i);

            users.add(user);
        }
        model.put("title", "測試的郵件");
        model.put("users", users);
        String[] toAddr = new String[] {"[e-mail]"};
        String[] ccAddr = new String[] {"[e-mail]"};
        String subject = "測試郵件，別當真";
        String html = FreeMarkerTemplateUtils.processTemplateIntoString(template, model);


        List<MailFileVo> srcVos = new ArrayList<>();
        MailFileVo mailFileSrc = new MailFileVo();
        mailFileSrc.setName("battle-field");
        mailFileSrc.setFile(new File(rootPath + "/static/battle-field.jpg"));
        srcVos.add(mailFileSrc);

        List<MailFileVo> athVos = new ArrayList<>();
        MailFileVo mailFileAth = new MailFileVo();
        mailFileAth.setName("你的附件.txt");
        mailFileAth.setFile(new File(rootPath + "/static/fu-jian.txt"));
        athVos.add(mailFileAth);

        // return HttpUtil.r200(html);

        mailService.sendMail(toAddr, ccAddr, subject, html, srcVos, athVos);
        return HttpUtil.r200("發送成功");
    }
}

3，瀏覽器訪問 http:ip:port/mail/port