首先，引入发送邮件的依赖，由于freemarker自定义模板，所以也需要把freemarker的依赖引入
pom.xml文件
<dependency>
<groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-mail</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-freemarker</artifactId> </dependency>
配置文件需要配置的信息：
spring.mail.host:smtp.qq.com
spring.mail.username:
spring.mail.password:
spring.mail.properties.mail.smtp.auth:true
spring.mail.properties.mail.debug:true
使用qq邮箱需要开通POP3/SMTP服务，具体方法自行百度。
实现轮询发送的类，这里主要就是将默认只保存一个用户的配置bean注入到本实例中，读取配置文件中的username和password，分割成多个用户和密码保存到队列中。重写doSend()方法实现轮询。具体代码如下：
package com.wangx.boot.mail;
import org.springframework.boot.autoconfigure.mail.MailProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties; import org.springframework.context.annotation.Configuration; import org.springframework.mail.MailException; import org.springframework.mail.javamail.JavaMailSender; import org.springframework.mail.javamail.JavaMailSenderImpl; import javax.mail.internet.MimeMessage; import java.util.ArrayList; import java.util.Map; import java.util.Properties; /** * 实现多账号，轮询发送 * @EnableConfigurationProperties注解将MailProperties这个保存邮件相关信息的bean注入到本类引用中 */ @Configuration @EnableConfigurationProperties(MailProperties.class) public class WangxJavaMailSenderImpl extends JavaMailSenderImpl implements JavaMailSender { //保存多个用户名和密码的队列 private ArrayList<String> usernameList; private ArrayList<String> passwordList; //轮询标识 private int currentMailId = 0; private final MailProperties properties; public WangxJavaMailSenderImpl(MailProperties properties) { this.properties = properties; // 初始化账号 if (usernameList == null) usernameList = new ArrayList<String>(); String[] userNames = this.properties.getUsername().split(","); if (userNames != null) { for (String user : userNames) { usernameList.add(user); } } // 初始化密码 if (passwordList == null) passwordList = new ArrayList<String>(); String[] passwords = this.properties.getPassword().split(","); if (passwords != null) { for (String pw : passwords) { passwordList.add(pw); } } } @Override protected void doSend(MimeMessage[] mimeMessage, Object[] object) throws MailException { super.setUsername(usernameList.get(currentMailId)); super.setPassword(passwordList.get(currentMailId)); // 设置编码和各种参数 super.setHost(this.properties.getHost()); super.setDefaultEncoding(this.properties.getDefaultEncoding().name()); super.setJavaMailProperties(asProperties(this.properties.getProperties())); super.doSend(mimeMessage, object); // 轮询 currentMailId = (currentMailId + 1) % usernameList.size(); } private Properties asProperties(Map<String, String> source) { Properties properties = new Properties(); properties.putAll(source); return properties; } @Override public String getUsername() { return usernameList.get(currentMailId); } }
实现模板加入模板发送的方法，主要是先定义好模板，然后将模板解析成字符串，组装MimeMessage对象，调用JavaMailSenderImpl的send方法发送，具体实现代码如下
package com.wangx.boot.component;
import com.wangx.boot.mail.WangxJavaMailSenderImpl;
import freemarker.template.TemplateException; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.mail.javamail.MimeMessageHelper; import org.springframework.stereotype.Component; import org.springframework.ui.freemarker.FreeMarkerTemplateUtils; import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer; import javax.mail.MessagingException; import javax.mail.internet.InternetAddress; import javax.mail.internet.MimeMessage; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.Map; /** * */ @Component public class WangxJavaMailComponent { private static final String template = "mail/wangx.ftl"; @Autowired private FreeMarkerConfigurer freeMarkerConfigurer; @Autowired private WangxJavaMailSenderImpl wangxJavaMailSender; public void sendMail(String email) { Map<String, Object> map = new HashMap<String, Object>(); map.put("email", email); try { //获取解析到的模板的字符串 String text = getTextByTemplate(template, map); send(email, text); } catch (Exception e) { e.printStackTrace(); } } /** * 解析模板文件，并将参数传入生成动态的字符串文返回 * @param template * @param model * @return * @throws IOException * @throws TemplateException */ private String getTextByTemplate(String template, Map<String, Object> model) throws IOException, TemplateException { return FreeMarkerTemplateUtils.processTemplateIntoString(freeMarkerConfigurer.getConfiguration().getTemplate(template), model); } /** * 组装 MimeMessage 对象并调用wangxJavaMailSender的send方法发送，在send方法中会调用我们angxJavaMailSenderW中重写的doSend方法 * @param email * @param text * @return * @throws MessagingException * @throws UnsupportedEncodingException */ private String send(String email, String text) throws MessagingException, UnsupportedEncodingException { MimeMessage message = wangxJavaMailSender.createMimeMessage(); MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8"); InternetAddress from = new InternetAddress(); from.setAddress(wangxJavaMailSender.getUsername()); from.setPersonal("Wangx", "UTF-8"); helper.setFrom(from); helper.setTo(email); helper.setSubject("测试邮件"); helper.setText(text, true); wangxJavaMailSender.send(message); return text; } }
测试发送的接口
package com.wangx.boot.controller;
import com.wangx.boot.component.WangxJavaMailComponent;
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.bind.annotation.RestController; @RestController @RequestMapping("/mail") public class MailController { @Autowired private WangxJavaMailComponent wangxJavaMailComponent; @RequestMapping("/send") @ResponseBody public String send(String mail) { wangxJavaMailComponent.sendMail(mail); return "success"; } }
访问http://localhost:8080/mail/send?mail=要发送的邮箱 即可发送邮件到你制定的邮箱。