Spring中使用FreeMaker或Vilocity模板发送邮件

本文以用户注册后为用户发送一封邮件为例子，讲述如何在Spring中使用FreeMaker或Vilocity发送邮件。

Spring配置文件：
<!-- 使用Spring封装的Mail Sender -->
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
<property name="host" value="smtp.163.com"/>
<property name="username" value="test"/>
<property name="password" value="123456"/>
<property name="javaMailProperties">
<props>
<prop key="mail.smtp.auth">true</prop>
</props>
</property>
</bean>

<!-- freemarker config -->
<bean id="freeMarkerConfigurer" class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
<property name="templateLoaderPath" value="/WEB-INF/freemakertemplate/" />
<property name="freemarkerSettings">
<props>
<prop key="template_update_delay">0</prop>
<prop key="default_encoding">GBK</prop>
<prop key="locale">zh_CN</prop>
</props>
</property>
</bean>

<!-- vilocity config -->
<bean id="velocityEngine" class="org.springframework.ui.velocity.VelocityEngineFactoryBean">
<property name="resourceLoaderPath" value="/WEB-INF/vilocitytemplate/" />
<property name="velocityProperties">
<props>
<prop key="velocimacro.library">*.vm</prop>
<prop key="default.contentType">text/html; charset=utf-8</prop>
<prop key="output.encoding">utf-8</prop>
<prop key="input.encoding">utf-8</prop>
</props>
</property>
</bean>

<bean id="mailMessage" class="org.springframework.mail.SimpleMailMessage" singleton="false">
<property name="from" value="[e-mail]"/>
</bean>

<bean id="mailEngine" class="test.MailEngine">
<property name="mailSender" ref="mailSender"/>
<!-- 如果使用Vilocity -->
<property name="velocityEngine" ref="velocityEngine"/>
<!-- 如果使用FreeMaker -->
<property name="freeMarkerConfigurer" ref="freeMarkerConfigurer" />
</bean>


MailEngine类：

public class MailEngine {
protected static final Log log = LogFactory.getLog(MailEngine.class);

// private FreeMarkerConfigurer freeMarkerConfigurer;
private VelocityEngine velocityEngine;
private MailSender mailSender;

// public void setFreeMarkerConfigurer(
// FreeMarkerConfigurer freeMarkerConfigurer) {
// this.freeMarkerConfigurer = freeMarkerConfigurer;
// }

public void setMailSender(MailSender mailSender) {
this.mailSender = mailSender;
}

public void setVelocityEngine(VelocityEngine velocityEngine) {
this.velocityEngine = velocityEngine;
}

/**
* 通过模板产生邮件正文
* @param templateName 邮件模板名称
* @param map 模板中要填充的对象
* @return 邮件正文（HTML）
*/
public String generateEmailContent(String templateName, Map map) {
//使用FreeMaker模板
// try {
// Configuration configuration = freeMarkerConfigurer.getConfiguration();
// Template t = configuration.getTemplate(templateName);
// return FreeMarkerTemplateUtils.processTemplateIntoString(t, map);
// } catch (TemplateException e) {
// log.error("Error while processing FreeMarker template ", e);
// } catch (FileNotFoundException e) {
// e.printStackTrace();
// //log.error("Error while open template file ", e);
// } catch (IOException e) {
// log.error("Error while generate Email Content ", e);
// }

// 使用Vilocity模板
try {
return VelocityEngineUtils.mergeTemplateIntoString(velocityEngine, templateName, map);
} catch (VelocityException e) {
log.error("Error while processing Vilocity template ", e);
}

return null;
}

/**
* 发送邮件
* @param emailAddress 收件人Email地址的数组
* @param fromEmail 寄件人Email地址, null为默认寄件人[e-mail]
* @param bodyText 邮件正文
* @param subject 邮件主题
* @param attachmentName 附件名
* @param resource 附件
* @throws MessagingException
*/
public void sendMessage(String[] emailAddresses, String fromEmail,
String bodyText, String subject, String attachmentName,
ClassPathResource resource) throws MessagingException {
MimeMessage message = ((JavaMailSenderImpl) mailSender)
.createMimeMessage();

// use the true flag to indicate you need a multipart message
MimeMessageHelper helper = new MimeMessageHelper(message, true);

helper.setTo(emailAddresses);
if(fromEmail != null){
helper.setFrom(fromEmail);
}
helper.setText(bodyText, true);
helper.setSubject(subject);

if(attachmentName!=null && resource!=null)
helper.addAttachment(attachmentName, resource);

((JavaMailSenderImpl) mailSender).send(message);
}

/**
* 发送简单邮件
* @param msg
*/
public void send(SimpleMailMessage msg) {
try {
((JavaMailSenderImpl) mailSender).send(msg);
} catch (MailException ex) {
//log it and go on
log.error(ex.getMessage());
}
}

/**
* 使用模版发送HTML格式的邮件
*
* @param msg 装有to,from,subject信息的SimpleMailMessage
* @param templateName 模版名,模版根路径已在配置文件定义于freemakarengine中
* @param model 渲染模版所需的数据
*/
public void send(SimpleMailMessage msg, String templateName, Map model) {
//生成html邮件内容
String content = generateEmailContent(templateName, model);
MimeMessage mimeMsg = null;
try {
mimeMsg = ((JavaMailSenderImpl) mailSender).createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(mimeMsg, true, "utf-8");
helper.setTo(msg.getTo());

if(msg.getSubject()!=null)
helper.setSubject(msg.getSubject());

if(msg.getFrom()!=null)
helper.setFrom(msg.getFrom());

helper.setText(content, true);

((JavaMailSenderImpl) mailSender).send(mimeMsg);
} catch (MessagingException ex) {
log.error(ex.getMessage(), ex);
}

}
}

发送邮件：
SimpleMailMessage message = (SimpleMailMessage) getBean("mailMessage");
message.setTo(user.getName() + "<" + user.getEmail() + ">");

Map<String, User> model = new HashMap<String, User>();
model.put("user", user);

MailEngine engine = (MailEngine)getBean("mailEngine");
//Vilocity模板
engine.send(message, "notifyUser.vm", model);
//FreeMaker模板
//engine.send(message, "NotifyUser.ftl", model);

以上的User为用户类。

Vilocity模板：
${user.name} 您好！您已成功注册为本站会员，您的信息如下：

${user.name}
${user.password}

FreeMaker模板：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>用户注册通知</title>
</head>
<body>
<p>${user.name} 您好，恭喜您，已经成为本站会员！</p>
<table>
<tr><td>用户名：</td><td>${user.name}</td></tr>
<tr><td>密码：</td><td>${user.password}</td></tr>
</table>
</body>
</html>