java发送html模板的高逼格邮件

Bertha 。 2022-01-07 06:37 297阅读 0赞

最近做了一个监测k8s服务pod水平伸缩发送邮件的功能（当pod的cpu/内存达到指定阈值后会水平扩展出多个pod、或者指定时间内pod数应扩展到指定数量），一开始写了个格式很low的邮件，像下面这样：

![在这里插入图片描述][20191019201305510.png]

主流程打通，算个v1版本吧，程序员是个追求完美的人，再说这么低逼格的邮件，给客户看，客户也会不满意。那怎么提高邮件的逼格呢？下面写了个简单的demo，v2版本如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9saWFiaW8uYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70]

感兴趣的小伙伴可以参考，模板可以找你公司前端和美工小姐姐设计。

因为监测k8s服务pod水平伸缩是用go开发的，发送通知邮件提供了个接口，用springboot写的，以下也用springboot做demo

Springboot的pom.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.2.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.example</groupId>
        <artifactId>email-demo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>email-demo</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>3.8.1</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.47</version>
            </dependency>
           
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-mail</artifactId>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

pod-scale-alarm.html模板文件：  
模板中的\{0\}、\{1\}这样的占位符后面java代码会替换掉

<body style="color: #666; font-size: 14px; font-family: 'Open Sans',Helvetica,Arial,sans-serif;">
    <div class="box-content" style="width: 80%; margin: 20px auto; max-width: 800px; min-width: 600px;">
        <div class="header-tip" style="font-size: 12px; color: #aaa; text-align: right; padding-right: 25px; padding-bottom: 10px;">
            Confidential - Scale Alarm Use Only
        </div>
        <div class="info-top" style="padding: 15px 25px; border-top-left-radius: 10px; border-top-right-radius: 10px; background: { 0}; color: #fff; overflow: hidden; line-height: 32px;">
            <img src="cid:icon-alarm" style="float: left; margin: 0 10px 0 0; width: 32px;" /><div style="color:#010e07"><strong>服务实例水平伸缩通知</strong></div>
        </div>
        <div class="info-wrap" style="border-bottom-left-radius: 10px; border-bottom-right-radius: 10px; border:1px solid #ddd; overflow: hidden; padding: 15px 15px 20px;">
            <div class="tips" style="padding:15px;">
                <p style=" list-style: 160%; margin: 10px 0;">Hi,</p>
                <p style=" list-style: 160%; margin: 10px 0;">{1}</p>
            </div>
            <div class="time" style="text-align: right; color: #999; padding: 0 15px 15px;">{2}</div>
            <br>
            <table class="list" style="width: 100%; border-collapse: collapse; border-top:1px solid #eee; font-size:12px;">
                <thead>
                <tr style=" background: #fafafa; color: #333; border-bottom: 1px solid #eee;">
                    {3}
                </tr>
                </thead>
                <tbody>
                {4}
                </tbody>
            </table>
        </div>
    </div>
    </body>

success-alarm.png图标：  
![在这里插入图片描述][20191019201323430.png]  
java代码如下，简单的demo，优化可以自己在项目中去做。

package com.example.emaildemo;
    
    import org.apache.commons.lang3.time.DateFormatUtils;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.core.io.ClassPathResource;
    import org.springframework.mail.javamail.JavaMailSenderImpl;
    import org.springframework.mail.javamail.MimeMessageHelper;
    
    import javax.mail.MessagingException;
    import javax.mail.internet.MimeMessage;
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.text.MessageFormat;
    import java.util.Date;
    import java.util.Objects;
    import java.util.Properties;
    
    /** * @program: email-demo * @description: * @author: smallsoup * @create: 2019-01-27 16:44 **/
    
    public class SendEmailUtil { 
    
        private static final Logger LOGGER = LoggerFactory.getLogger(SendEmailUtil.class);
    
        public static void main(String[] args) throws MessagingException, IOException { 
    
            JavaMailSenderImpl javaMailSender = new JavaMailSenderImpl();
            javaMailSender.setUsername("你的邮箱地址");
            javaMailSender.setPassword("你的邮箱AUTH密码,不是登陆密码哦,在邮箱的设置里单独开启和设置");
            javaMailSender.setHost("smtp.exmail.qq.com");
            javaMailSender.setPort(587);
            javaMailSender.setDefaultEncoding("UTF-8");
            Properties props = new Properties();
            props.setProperty("mail.smtp.host", "smtp.exmail.qq.com");
            props.setProperty("mail.transport.protocol", "smtp");
            props.setProperty("mail.smtp.auth", "true");
            props.setProperty("mail.smtp.connectiontimeout", "20000");
            props.setProperty("mail.smtp.timeout", "20000");
            javaMailSender.setJavaMailProperties(props);
    
            MimeMessage message = javaMailSender.createMimeMessage();
            MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8");
            helper.setTo(new String[]{ "收件人邮箱"});
            helper.setCc("抄送人邮箱");
            helper.setFrom("你的邮箱地址");
            helper.setSubject("liang subject");
            helper.setText(buildContent(), true);
    
    
            String alarmIconName = "success-alarm.png";
            ClassPathResource img = new ClassPathResource(alarmIconName);
            if (Objects.nonNull(img)) { 
                helper.addInline("icon-alarm", img);
            }
            javaMailSender.send(message);
        }
    
        private static String buildContent() throws IOException { 
    
            //加载邮件html模板
            String fileName = "pod-scale-alarm.html";
            InputStream inputStream = ClassLoader.getSystemResourceAsStream(fileName);
            BufferedReader fileReader = new BufferedReader(new InputStreamReader(inputStream));
            StringBuffer buffer = new StringBuffer();
            String line = "";
            try { 
                while ((line = fileReader.readLine()) != null) { 
                    buffer.append(line);
                }
            } catch (Exception e) { 
                LOGGER.error("读取文件失败，fileName:{}", fileName, e);
            } finally { 
                inputStream.close();
                fileReader.close();
            }
    
    
            String contentText = "以下是服务实例伸缩信息, 敬请查看.<br>below is the information of service instance scale, please check. ";
            //邮件表格header
            String header = "<td>分区(Namespace)</td><td>服务(Service)</td><td>伸缩结果(Scale Result)</td><td>伸缩原因(Scale Reason)</td><td>当前实例数(Pod instance number)</td>";
            StringBuilder linesBuffer = new StringBuilder();
            linesBuffer.append("<tr><td>" + "myNamespace" + "</td><td>" + "myServiceName" + "</td><td>" + "myscaleResult" + "</td>" +
                    "<td>" + "mReason" + "</td><td>" + "my4" + "</td></tr>");
    
            //绿色
            String emailHeadColor = "#10fa81";
            String date = DateFormatUtils.format(new Date(), "yyyy/MM/dd HH:mm:ss");
            //填充html模板中的五个参数
            String htmlText = MessageFormat.format(buffer.toString(), emailHeadColor, contentText, date, header, linesBuffer.toString());
    
            //改变表格样式
            htmlText = htmlText.replaceAll("<td>", "<td style=\"padding:6px 10px; line-height: 150%;\">");
            htmlText = htmlText.replaceAll("<tr>", "<tr style=\"border-bottom: 1px solid #eee; color:#666;\">");
            return htmlText;
        }
    }

--------------------

# 作者简洁 #

> 作者：小碗汤，一位热爱、认真写作的小伙，目前维护原创公众号：『我的小碗汤』，专注于写golang、docker、kubernetes等知识等提升硬实力的文章，期待你的关注。 转载说明：务必注明来源（注明：来源于公众号：我的小碗汤， 作者：小碗汤）

[20191019201305510.png]: /images/20211227/66c10b4b819e41558bc9210331355323.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9saWFiaW8uYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70]: /images/20211227/3916c94c6cb34ba08472f6cfc81d3ea0.png
[20191019201323430.png]: /images/20211227/f24e5872671e4b339f1aa9ee9f29f2e2.png