使用spring javamail smtp发送html邮件

      最近项目中使用到了spring javamail进行定时邮件发送，网上的例子质量参差不齐，说的不是很清楚，这里简单的介绍自己写的程序，一是与大家分享，另外做为笔记供自己以后参考。

      1. 首先我们看在spring中如何配置javamail

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
    <property name="host" value="${metrix.smtp.server}" />
    <property name="port" value="${metrix.smtp.port}" />
    <property name="username" value="${metrix.smtp.user}" />
    <property name="password" value="${metrix.smtp.password}" />
    <property name="javaMailProperties">
        <props>
            <prop key="mail.smtp.auth">${metrix.smtp.auth}</prop>
            <prop key="mail.smtp.timeout">${metrix.smtp.timeout}</prop>
        </props>
    </property>
</bean>

<bean id="mimeMessageHelperAdapter" class="com.alibaba.corp.metrix.admin.biz.dataprocess.utils.MimeMessageHelperAdapter">
    <property name="from" value="${metrix.smtp.from.address}"/>
    <property name="tos" value="${metrix.smtp.to.address}"/>
    <property name="personal" value="${metrix.smtp.from.personal}"/>
</bean>

    如果你的smtp邮件服务器不需要认证，可以将properties中mail.smtp.auth设置为false.

    2. 为了便于设置MimeMessageHelper的属性，定义了一个MimeMessageHelperAdapter类，在spring中进行配置，代码如下

package com.alibaba.corp.metrix.admin.biz.dataprocess.utils;

/**
 * Copyright 1999-2100 Alibaba.com All right reserved. This software is the
 * confidential and proprietary information of Alibaba.com
 * ("Confidential Information"). You shall not disclose such Confidential
 * Information and shall use it only in accordance with the terms of the license
 * agreement you entered into with Alibaba.com.
 *
 * @Author: leon Mao
 * @Date: 07/13/2012
 * @Time: 11:49
 * @Description:
 */

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class MimeMessageHelperAdapter {
    Logger logger = LoggerFactory.getLogger(MimeMessageHelperAdapter.class);
    private String from;
    private String tos;
    private String personal;

    public String getFrom() {
        return from;
    }

    public void setFrom(String from) {
        this.from = from;
    }

    public String getTos() {
        return tos;
    }

    public String[] getTosArray() {
        if (this.tos != null) {
            return StringUtils.split(this.tos, ',');
        } else {
            logger.warn("email receiver(s) not configured yet!");
            return null;
        }
    }

    public void setTos(String tos) {
        this.tos = tos;
    }

    public String getPersonal() {
        return personal;
    }

    public void setPersonal(String personal) {
        this.personal = personal;
    }
}

   3. 定义mailsender工具类

package com.alibaba.corp.metrix.admin.biz.dataprocess.utils;

import java.io.UnsupportedEncodingException;

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

import org.springframework.mail.javamail.JavaMailSenderImpl;
import org.springframework.mail.javamail.MimeMessageHelper;

import com.alibaba.corp.metrix.admin.biz.dataprocess.job.base.BeanFactoryUtil;

/**
 * Copyright 1999-2100 Alibaba.com All right reserved. This software is the
 * confidential and proprietary information of Alibaba.com
 * ("Confidential Information"). You shall not disclose such Confidential
 * Information and shall use it only in accordance with the terms of the license
 * agreement you entered into with Alibaba.com.
 *
 * @Author: leon Mao
 * @Date: 07/13/2012
 * @Time: 12:01
 * @Description:
 */
public class MailSenderUtil {
    public static void sendMail(String subject, String content, Boolean html, String[] tos)
            throws MessagingException, UnsupportedEncodingException {
        JavaMailSenderImpl javaMailSender = (JavaMailSenderImpl) BeanFactoryUtil
                .getBean("mailSender");
        MimeMessageHelperAdapter mimeMessageHelperAdapter = (MimeMessageHelperAdapter) BeanFactoryUtil
                .getBean("mimeMessageHelperAdapter");

        MimeMessage message = javaMailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true, "GBK");
        helper.setFrom(mimeMessageHelperAdapter.getFrom(), mimeMessageHelperAdapter.getPersonal());
        helper.setSubject(subject);
        if (tos == null || tos.length == 0) {
            helper.setTo(mimeMessageHelperAdapter.getTosArray());
        } else {
            helper.setTo(tos);//推送Job中meta-info中设定的邮件接收者
        }
        helper.setText(content, html);
        javaMailSender.send(message);
    }
}

    这里sendMail方法中的html参数定义mime类型，这样outlook等邮件客户端会将收到的内容自动以html解析。

    4. 由于邮件的内容及长度不同，如果硬编码内容在java代码中，往往使得代码丑陋，也不够灵活，所以我们可以使用Velocity来渲染邮件内容。

public class MailContentGenerator {
    public static final String PREFIX = "classpath:result/";

    public static String generateMailContent(List results, String vmName) throws IOException {
        VelocityContext context = new VelocityContext();
        context.put("results", results);

        Reader reader = new InputStreamReader(Resources.getResourceAsStream(PREFIX + vmName),
                "GBK");
        StringWriter writer = new StringWriter(1024 * 512);
        Velocity.evaluate(context, writer, "", reader);
        return writer.toString();
    }
}

  5. velocity模板的例子

<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=GBK"/>
    <style type="text/css">
        thead tr {
            background-color: ActiveCaption;
            color: CaptionText;
        }

        th, td {
            vertical-align: top;
            font-family: "Tahoma";
            font-size: 10pt;
            padding: 3px;
        }

        table, th, td {
            border: 1px solid silver;
        }

        table {
            border-collapse: collapse;
        }
    </style>

</head>
<body>
<div style="font-size:12pt;">
    <table>
        <tbody>
        <tr>
            <th>序号</th>
            <th>标题</th>
            <th>产品线</th>
            <th>团队</th>
            <th>开发</th>
            <th>QA</th>
            <th>PE</th>
            <th>发布包</th>
            <th>上线手册</th>
            <th>上线时间</th>
        </tr>
            #foreach ($result in $results)
            <tr>
                <td>$velocityCount</td>
                #foreach ($element in $result)
                    <td>$!element</td>
                #end
            </tr>
            #end
        </tbody>
    </table>
</div>
</body>
</html>

     6. 主要依赖的包

      spring、misc.mail、java.servlet、jakarta.velocity