Java springboot 发送邮箱，普通文字、HTML（普通拼接HTML、使用freemaker 生成HTML）、附件、图片

一、maven项目添加依赖

    org.springframework.boot
    spring-boot-starter-mail



    org.freemarker
    freemarker

二、接口编写

service 层

/**
 * @Description 发送邮件接口
 */
public interface MailService {

    /**
     * @Description 发送简单的文本文件，to:收件人 subject:主题 content:内容
     * @Param [to, subject, content]
     **/
    public void sendSimpleMail(String to, String subject, String content);

    /**
     * @Description 发送html，to:收件人 subject:主题 content:内容
     * @Param [to, subject, content]
     **/
    public void sendHtmlMail(String to, String subject, String content);

    /**
     * @Description 发送一个带附件的邮件
     * @param to 收件人
     * @param subject 主题
     * @param content 内容
     * @param filePath 文件路径
     */
    public void sendAttachmentMail(String to, String subject, String content, String filePath);
    
    /**
     * @Description 发送一个图片带附件的邮件
     * @param to 收件人
     * @param subject 主题
     * @param content 内容
     * @param rscPath 图片
     */
    public void sendInlineResourceMail(String to, String subject, String content, String rscPath);
}

serviceImpl 

import java.io.File;

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

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.Service;

/**
 */
@Service
public class MailServiceImpl implements MailService {

    // 发送人的用户名，邮箱地址
    @Value("${spring.mail.username}")
    private String from;

    /**
     * JavaMailSender 用来发送邮件
     * springboot application.properties 文件设置 spring.mail
     */
    @Autowired
    private JavaMailSender mailSender;

    private final Logger logger = LoggerFactory.getLogger(this.getClass());
    
    @Override
    public void sendSimpleMail(String to, String subject, String content) {
        SimpleMailMessage mailMessage = new SimpleMailMessage();
        mailMessage.setFrom(from);
        mailMessage.setTo(to);
        mailMessage.setSubject(subject);
        mailMessage.setText(content);
        mailSender.send(mailMessage);
    }

    @Override
    public void sendHtmlMail(String to, String subject, String content) {
        MimeMessage message = mailSender.createMimeMessage();
        try {
            MimeMessageHelper messageHelper = new MimeMessageHelper(message);

            messageHelper.setFrom(from);
            messageHelper.setTo(to);
            messageHelper.setSubject(subject);
            //将content里面的标签进行处理,否则为正常的文本处理
            messageHelper.setText(content, true);
        } catch (MessagingException e) {
            logger.error("something wrong...");
            e.printStackTrace();
        }
        mailSender.send(message);

    }

    @Override
    public void sendAttachmentMail(String to, String subject, String content, String filePath) {

        MimeMessage mimeMessage = mailSender.createMimeMessage();
        try {
            // 带上附件，参数传true,否则会报错.
            // Not in multipart mode - create an appropriate MimeMessageHelper via a constructor that takes a 'multipart' flag if you need to set alternative texts or add inline elements or attachments.
            MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage, true);
            messageHelper.setFrom(from);

            messageHelper.setTo(to);
            messageHelper.setSubject(subject);
            messageHelper.setText(content);
            
            //设置附件
            FileSystemResource fileSystemResource = new FileSystemResource(new File(filePath));
            String filename = fileSystemResource.getFilename();
            messageHelper.addAttachment(filename, fileSystemResource);
        } catch (MessagingException e) {
            logger.error("something wrong...");
            e.printStackTrace();
        } finally {
		}
        mailSender.send(mimeMessage);
    }

    @Override
    public void sendInlineResourceMail(String to, String subject, String content, String rscPath) {

        MimeMessage mimeMessage = mailSender.createMimeMessage();
        try {
            //带上附件，参数传true,否则会报错.
            //Not in multipart mode - create an appropriate MimeMessageHelper via a constructor that takes a 'multipart' flag if you need to set alternative texts or add inline elements or attachments.
            MimeMessageHelper messageHelper = new MimeMessageHelper(mimeMessage, true);
            messageHelper.setFrom(from);
            messageHelper.setTo(to);
            messageHelper.setSubject(subject);
            messageHelper.setText(content,true);
            //构造邮件内部的图片
            FileSystemResource file = new FileSystemResource(new File(rscPath));
            //对应的图片src路径
            messageHelper.addInline("img", file);
        } catch (MessagingException e) {
            logger.error("something wrong...");
            e.printStackTrace();
        }
        mailSender.send(mimeMessage);
    }
}

三、application.propertis 文件配置

springboot 使用邮箱的方式
# QQ/163邮箱
#smtp.163.com smtp.qq.com
#spring.mail.host=smtp.qq.com
#spring.mail.username=账号
#spring.mail.password=授权码
#spring.mail.properties.mail.smtp.auth=true
#spring.mail.properties.mail.smtp.starttls.enable=true
#spring.mail.properties.mail.smtp.starttls.required=true
#spring.mail.default-encoding=UTF-8

# 腾讯企业邮箱
spring.mail.host=smtp.exmail.qq.com
spring.mail.username=账号
spring.mail.password=密码
spring.mail.protocol=smtp
spring.mail.default-encoding=UTF-8
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.socketFactory.class=javax.net.ssl.SSLSocketFactory
spring.mail.properties.mail.smtp.socketFactory.fallback=false
#腾讯企业邮箱 端口的写法有些区别
spring.mail.properties.mail.smtp.socketFactory.port=465

QQ授权码获取: POP3/SMTP服务 开启后会得到授权码

163 （网易）开启授权码

XML 配置 FreeMarkerConfigurer / 也可直接创建对象（读取ftl文佳，生成HTML）

  
  
      
      
          
             1800模板更新延时  
             UTF-8  
             zh_CN  
          
    

mail.ftl freeMaker模板编写

    
        
    
    
        用户名为：${name}

        ${id}
    

四、springboot 测试

package com.monitor.application;

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 com.monitor.email.MailService;

/**
 * springboot 邮箱测试类
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class MailSendTest {

    @Autowired
    private MailService mailService;

    @Autowired
    private FreeMarkerConfigurer freeMarkerConfigurer;
    
    private String to = "[email protected]";

    //主题
    String subject = "主题内容";

    @Test
    public void test01() {
        String content = "一个简单的文本发送";

        mailService.sendSimpleMail(to,subject,content);
    }

    @Test
    public void test02() {
        String content = " 
一个简单的html发送
";

        mailService.sendHtmlMail(to,subject,content);
    }

    @Test
    // XML配置：发送html文件，通过freemarker模板构造
    public void getFreemarkerByXml() throws IOException, TemplateException {
    	Template template =  freeMarkerConfigurer.getConfiguration().getTemplate("mail.ftl");
	    
	    // FreeMarker通过Map传递动态数据
	    Map map = new HashMap();
	    // 注意动态数据的key和模板标签中指定的属性相匹配
	    map.put("name","freeMarker 姓名");
	    map.put("id","ID：456125");
	    
	    // 解析模板并替换动态数据，最终content将替换模板文件中的${content}标签。
	    String htmlTxt = FreeMarkerTemplateUtils.processTemplateIntoString(template,map);
	    
	    mailService.sendHtmlMail(to, subject , htmlTxt);
    }

    @Test
    // 创建对象：通过freemarker模板构造邮件内容
    public void getFreemarkerByObject() throws IOException, TemplateException {
        
	    // 通过指定模板名获取FreeMarker模板实例
        
        FreeMarkerConfigurer freeMarkerConfigurer = new FreeMarkerConfigurer();
		
		Properties settings = new Properties();
		settings.setProperty("locale", "zh_CN");
		settings.setProperty("default_encoding", "UTF-8");
		freeMarkerConfigurer.setFreemarkerSettings(settings);
		
		String path = System.getProperty("user.dir");  // 获取项目根目录
		FileTemplateLoader ftl1 = new FileTemplateLoader(new File(path + "\\src\\main\\resources\\templates"));  // 拼接上自己对应的模板位置
		ClassTemplateLoader ctl = new ClassTemplateLoader(getClass(), "");
		TemplateLoader[] loaders = new TemplateLoader[] { ftl1, ctl };  // 可配置多个路径， ftl2，ftl3 ，添加在{} 里面即可.
		MultiTemplateLoader mtl = new MultiTemplateLoader(loaders);
		
		Configuration configuration = new Configuration(Configuration.VERSION_2_3_28);  // 根据自己引入的版本设置
		configuration.setTemplateLoader(mtl);
		
		freeMarkerConfigurer.setConfiguration(configuration);
		
		
	    Template template =  freeMarkerConfigurer.getConfiguration().getTemplate("mail.ftl");
	    
	    // FreeMarker通过Map传递动态数据
	    Map map = new HashMap();
	    // 注意动态数据的key和模板标签中指定的属性相匹配
	    map.put("name","freeMarker 姓名");
	    map.put("id","ID456125");
	    
	    // 解析模板并替换动态数据，最终content将替换模板文件中的${content}标签。
	    String htmlTxt = FreeMarkerTemplateUtils.processTemplateIntoString(template,map);
	    
	    mailService.sendHtmlMail(to, subject , htmlTxt);
    }

    @Test
    public void test04() {
        String content = "一个简单的带附件发送";

        String filePath = "C:\\Users\\DELL\\Desktop\\Test.docx";
        mailService.sendAttachmentMail(to,subject,content,filePath);
    }

    @Test
    //发送图片
    public void test05() {
        //src对应img
        String content = "一个简单的图片发送：";
        //图片地址
        String filePath = "D:\\head.png";
        mailService.sendInlineResourceMail(to,subject,content,filePath);
    }
}

五、验证邮箱是否真实有效

大佬文章：Java与邮件系统交互之使用Socket验证邮箱是否存在（非正则表达式）

 

其它实现大佬：Spring结合freemaker配置发送邮件， XML 文件配置