Java发送邮件初窥

一、背景

　　最近朋友的公司有用到这个功能，之前对这一块也不是很熟悉，就和他一起解决出现的异常的同时，也初窥一下使用Apache Common Email组件进行邮件发送。

二、Java发送邮件的注意事项

　　1.不同的邮箱有不同的支持协议，比如有些只支持SSL协议，有些只支持TLS协议，还有些同时支持SSL和TLS协议。

　　2.支持不同协议的邮箱，在使用Java发送邮件时要使用不同的方式发送，下面我会介绍基于SSL和TLS的两种实现方式。

　　附：常用邮箱的服务器(Smtp/POP3)地址和端口总结

三、代码实现

说明：本例采用Apache Common Email组件进行开发。

1.发送邮件实体类

 package com.hafiz.zhang.mail.entity;

 import java.io.Serializable;
 import java.util.List;

 import org.apache.commons.mail.EmailAttachment;

 /**
  * @author hafiz.Zhang
  * @Date 2016年5月23日 下午2:40:36
  * @Description 邮件实体类
  */
 public class MailEntity implements Serializable{
     private static final long serialVersionUID = 1589570366044890462L;
     public static final String ENCODING = "UTF-8";    //邮件编码
     private String host;                            　//服务器地址
     private String port;                              //发送端口
     private String sender;                            //发件人邮箱
     private List<String> receiver;                    //收件人邮箱
     private List<String> copier;                      //抄送人
     private String senderName;                        //发件人昵称
     private String userName;                          //发件邮箱账号
     private String password;                          //发件邮箱密码
     private String subject;                           //邮件主题
     private String content;                           //邮件内容(支持HTML)
     private List<EmailAttachment> attachments;        //邮件附件
     public String getHost() {
         return host;
     }
     public void setHost(String host) {
         this.host = host;
     }
     public String getPort() {
         return port;
     }
     public void setPort(String port) {
         this.port = port;
     }
     public String getSender() {
         return sender;
     }
     public void setSender(String sender) {
         this.sender = sender;
     }
     public List<String> getReceiver() {
         return receiver;
     }
     public void setReceiver(List<String> receiver) {
         this.receiver = receiver;
     }
     public List<String> getCopier() {
         return copier;
     }
     public void setCopier(List<String> copier) {
         this.copier = copier;
     }
     public String getSenderName() {
         return senderName;
     }
     public void setSenderName(String senderName) {
         this.senderName = senderName;
     }
     public String getUserName() {
         return userName;
     }
     public void setUserName(String userName) {
         this.userName = userName;
     }
     public String getPassword() {
         return password;
     }
     public void setPassword(String password) {
         this.password = password;
     }
     public String getSubject() {
         return subject;
     }
     public void setSubject(String subject) {
         this.subject = subject;
     }
     public String getContent() {
         return content;
     }
     public void setContent(String content) {
         this.content = content;
     }
     public List<EmailAttachment> getAttachments() {
         return attachments;
     }
     public void setAttachments(List<EmailAttachment> attachments) {
         this.attachments = attachments;
     }
     @Override
     public String toString() {
         return "MailEntity [host=" + host + ", port=" + port + ", sender=" + sender + ", receiver=" + receiver
                 + ", copier=" + copier + ", senderName=" + senderName + ", userName=" + userName + ", password="
                 + password + ", subject=" + subject + ", content=" + content + ", attachments=" + attachments + "]";
     }
 }

注：实体类代码比较臃肿，建议使用lombok进行简化，lombok的使用方式见我的另一篇博客：Java简化代码神器-Lombok

2.发送邮件支持协议列举类

 package com.hafiz.zhang.mail.tools.factory;

 /**
  * @author hafiz.Zhang
  * @Date 2016年5月25日 下午12:08:59
  * @Description 列举发送邮件的可用协议
  */
 public class Protocols {
     //SSL协议
     public static String SSL_MAIL_UTIL = "com.hafiz.zhang.mail.tools.SSLMailUtil";
     //TLS协议
     public static String TLS_MAIL_UTIL = "com.hafiz.zhang.mail.tools.TLSMailUtil";
 }

3.发送邮件工具接口类

 package com.hafiz.zhang.mail.tools;

 import com.hafiz.zhang.mail.entity.MailEntity;

 /**
  * @author hafiz.Zhang
  * @Date 2016年5月23日 下午3:26:15
  * @Description 邮件发送接口类
  */
 public interface IMailUtil {
     /**
      * @Author hafiz.Zhang
      * @Description:  发送邮件
      * @param    mail要发送邮件的实体类
      * @return Boolean   发送结果
      */
     public abstract Boolean send(MailEntity mail);
 }

4.基于SSL协议发送邮件工具实现类

 package com.hafiz.zhang.mail.tools;

 import java.util.List;

 import org.apache.commons.mail.EmailAttachment;
 import org.apache.commons.mail.EmailException;
 import org.apache.commons.mail.HtmlEmail;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import com.hafiz.zhang.mail.entity.MailEntity;

 /**
  * @author hafiz.Zhang
  * @Date 2016年5月23日 下午3:09:13
  * @Description 通过SSL方式发送邮件工具类
  */
 public class SSLMailUtil implements IMailUtil{
     private static Logger log = LoggerFactory.getLogger(SSLMailUtil.class);

     public Boolean send(MailEntity mail) {
         // 创建待发送的emil对象
         HtmlEmail email = new HtmlEmail();
         try {

             // 设置SMTP发送服务器的名字：163的如下："smtp.163.com"
             email.setHostName(mail.getHost());
             //设置端口号
             if(null != mail.getPort()) {
                 email.setSmtpPort(Integer.parseInt(mail.getPort()));
             }
             // 设置邮件字符编码集
             email.setCharset(MailEntity.ENCODING);
             // 设置抄送人
             email.addCc(mail.getCopier().toArray(new String[mail.getCopier().size()]));
             // 设置发送人的邮箱
             email.setFrom(mail.getSender(), mail.getSenderName());
             // 收件人的邮箱
             email.addTo(mail.getReceiver().toArray(new String[mail.getReceiver().size()]));
             // 如果需要认证信息的话，设置认证：用户名-密码。分别为发件人在邮件服务器上的注册名称和密码
             email.setAuthentication(mail.getUserName(), mail.getPassword());
             // 设置要发送的邮件主题
             email.setSubject(mail.getSubject());
             // 设置要发送的信息，由于使用了HtmlEmail，可以在邮件内容中使用HTML标签
             email.setMsg(mail.getContent());
             // 设置附件
             List<EmailAttachment> attachments = mail.getAttachments();
             if(null != attachments && attachments.size() > 0) {
                 for(EmailAttachment attachment : attachments) {
                     email.attach(attachment);
                 }
             }
             // 发送
             email.send();

             log.info(mail.getSender() + " 发送邮箱到 " + mail.getReceiver());

             return true;
         } catch (EmailException e) {
             log.error(mail.getSender() + " 发送邮箱到 " + mail.getReceiver() + " 失败,错误原因：" + e.getMessage());
             e.printStackTrace();
         }
         return false;
     }
 }

5.基于TLS协议的发送邮件实现类

 package com.hafiz.zhang.mail.tools;

 import java.util.List;
 import java.util.Properties;

 import javax.mail.Session;

 import org.apache.commons.mail.DefaultAuthenticator;
 import org.apache.commons.mail.EmailAttachment;
 import org.apache.commons.mail.EmailException;
 import org.apache.commons.mail.HtmlEmail;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import com.hafiz.zhang.mail.entity.MailEntity;

 /**
  * @author hafiz.Zhang
  * @Date 2016年5月23日 下午3:23:15
  * @Description 通过TLS协议发送邮件工具类
  */
 public class TLSMailUtil implements IMailUtil{
     private static Logger log = LoggerFactory.getLogger(TLSMailUtil.class);

     public Boolean send(MailEntity mail){
         HtmlEmail email = new HtmlEmail();
         try {
             Properties prop = new Properties();
             // 设置SMTP发送服务器的名字：163的如下："smtp.163.com"
             prop.setProperty("mail.smtp.host", mail.getHost());
             // 设置SMTP发送服务器的端口
             prop.setProperty("mail.smtp.port", mail.getPort());
             // 设置是否需要认证
             prop.setProperty("mail.smtp.auth", "true");
             // 开启TLS加密方式
             prop.setProperty("mail.smtp.starttls.enable", "true");
             // 添加信任的服务器
             prop.setProperty("mail.smtp.ssl.trust", mail.getHost());
             // 进行认证并获取需要的session
             DefaultAuthenticator defaultAuthenticator =
                     new DefaultAuthenticator(mail.getUserName(), mail.getPassword());
             Session session = Session.getInstance(prop,defaultAuthenticator);
             email.setMailSession(session);
             // 设置字符编码集
             email.setCharset(MailEntity.ENCODING);
             // 设置发送人的邮箱
             email.setFrom(mail.getSender(), mail.getSenderName());
             // 设置收件人的邮箱
             email.addTo(mail.getReceiver().toArray(new String[mail.getReceiver().size()]));
             // 设置抄送人
             email.addCc(mail.getCopier().toArray(new String[mail.getCopier().size()]));
             // 设置要发送的邮件主题
             email.setSubject(mail.getSubject());
             // 设置要发送的信息，由于使用了HtmlEmail，可以在邮件内容中使用HTML标签
             email.setMsg(mail.getContent());
             // 设置附件
             List<EmailAttachment> attachments = mail.getAttachments();
             if(null != attachments && attachments.size() > 0) {
                 for(EmailAttachment attachment : attachments) {
                     email.attach(attachment);
                 }
             }
             // 发送
             email.send();
             log.info(mail.getSender() + " 发送邮箱到 " + mail.getReceiver());
             return true;
         } catch (EmailException e) {
             log.error(mail.getSender() + " 发送邮箱到 " + mail.getReceiver() + " 失败,错误原因：" + e.getMessage());
             e.printStackTrace();
         }
         return false;
     }
 }

注意：

　　1.如果没有设置开启TLS加密方式的代码（上面代码中标红处），则会出现Caused by: com.sun.mail.smtp.SMTPSendFailedException: 530 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM异常，异常图片如下：

　　2.如果没有设置添加信任的主机服务器的代码（上面代码中标红处），则会出现：Caused by: javax.mail.MessagingException: Could not convert socket to TLS;异常，异常图片如下：

6.获取邮件发送类的工厂类

 package com.hafiz.zhang.mail.tools.factory;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import com.hafiz.zhang.mail.tools.IMailUtil;

 /**
  * @author hafiz.Zhang
  * @Date 2016年5月23日 下午3:43:15
  * @Description 获取邮件发送类的工厂类
  */
 public class MailUtilsFactory {
     private static Logger logger = LoggerFactory.getLogger(MailUtilsFactory.class);

     private MailUtilsFactory() {
         super();
     }

     public static IMailUtil getMailUtil(String name) {
         IMailUtil mailUtil = null;
         try {
             mailUtil = (IMailUtil)Class.forName(name).newInstance();
         } catch (Exception e) {
             logger.error("获取邮件发送类失败,失败原因:" + e.getMessage());
             e.printStackTrace();
         }
         return mailUtil;
     }
 }

7.测试类

 package com.hafiz.zhang.mail.test;

 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;

 import org.apache.commons.mail.Email;
 import org.apache.commons.mail.EmailAttachment;

 import com.hafiz.zhang.mail.entity.MailEntity;
 import com.hafiz.zhang.mail.tools.IMailUtil;
 import com.hafiz.zhang.mail.tools.factory.MailUtilsFactory;
 import com.hafiz.zhang.mail.tools.factory.Protocols;

 /**
  * @author hafiz.Zhang
  * @Date 2016年5月23日 下午3:39:52
  * @Description 两种方式发送邮件的测试类
  */
 public class TestMailSender {
     public static void main(String[] args) throws MalformedURLException {
         MailEntity mail = new MailEntity();
         mail.setHost("smtp.163.com");
         mail.setSender("xxx@163.com");
         mail.setPort("25");
         mail.setUserName("xxx@163.com");
         mail.setPassword("xxxxx");
         //设置收件人
         List<String> receiver = new ArrayList<String>();
         receiver.add("xxx@qq.com");
 　　　　 //设置抄送人
         List<String> copier = new ArrayList<String>();
         copier.add("xxx@163.com");

         List<EmailAttachment> attachments = new ArrayList<EmailAttachment>();
         // 添加本地附件
         EmailAttachment att = new EmailAttachment();
         att.setDescription("这是附件图片");
         att.setDisposition(EmailAttachment.ATTACHMENT);
         att.setName("好看的图片.png");
         att.setPath("C:\\Users\\ZHF\\Desktop\\333.png");
         attachments.add(att);
         // 添加网络附件
         EmailAttachment att2 = new EmailAttachment();
         att2.setDescription("这是网络附件");
         att2.setDisposition(EmailAttachment.ATTACHMENT);
         att2.setName("网络附件.jpg");
         att2.setURL(new URL("http://7xpsw5.com1.z0.glb.clouddn.com/41a9ccf2-2a22-44bd-aa3b-8e8779db1caf.jpg"));
         attachments.add(att2);

         mail.setAttachments(attachments);
         mail.setCopier(copier);
         mail.setReceiver(receiver);
         mail.setSubject("测试邮件发送主题");
 　　　　 // String string = "<html><head></head><body><div>测试Java发送邮件内容</div></body></html>";
         String string = "测试Java发送邮件内容";
         mail.setContent(string);
         // IMailUtil mailUtil = MailUtilsFactory.getMailUtil(Protocols.SSL_MAIL_UTIL);
         IMailUtil mailUtil = MailUtilsFactory.getMailUtil(Protocols.TLS_MAIL_UTIL);
         mailUtil.send(mail);
         System.out.println("邮件发送成功");
     }
 }

8.工程pom.xml文件（由于本例使用maven工程）

 <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>

   <groupId>com.hafiz.zhang</groupId>
   <artifactId>sendEmail</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>sendEmail</name>
   <url>http://maven.apache.org</url>

   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>

   <dependencies>
      <dependency>
          <groupId>org.apache.commons</groupId>
          <artifactId>commons-email</artifactId>
          <version>1.4</version>
      </dependency>
      <dependency>
         <groupId>org.slf4j</groupId>
         <artifactId>slf4j-log4j12</artifactId>
         <version>1.6.4</version>
      </dependency>
      <dependency>
         <groupId>org.slf4j</groupId>
         <artifactId>slf4j-api</artifactId>
         <version>1.6.4</version>
      </dependency>
      <dependency>
          <groupId>log4j</groupId>
          <artifactId>log4j</artifactId>
          <version>1.2.16</version>
      </dependency>
      <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>4.12</version>
      </dependency>
   </dependencies>
 </project>

至于，本文为何采用slf4j而不是直接采用log4j进行日志控制输出，详见另一篇博客：slf4j介绍以及实现原理窥探

9.日志输出格式文件

 ### set log levels ###
 log4j.rootLogger = DEBUG ,  stdout , D , E , F

 ### \u8F93\u51FA\u5230\u63A7\u5236\u53F0 ###
 log4j.appender.stdout = org.apache.log4j.ConsoleAppender
 log4j.appender.stdout.Target = System.out
 log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
 log4j.appender.stdout.layout.ConversionPattern =  %-d{yyyy-MM-dd HH:mm:ss} [ %p ] [ %l-%t:%r ] %m%n

 ## \u8F93\u51FA\u5230\u65E5\u5FD7\u6587\u4EF6 ###
 log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
 log4j.appender.D.DatePattern = '.'yyyyMMdd
 log4j.appender.D.File = logs/api/warn.log
 log4j.appender.D.Append = true
 log4j.appender.D.Threshold = WARN
 log4j.appender.D.layout = org.apache.log4j.PatternLayout
 log4j.appender.D.encoding=UTF-8
 log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %p ] [ %l-%t:%r ] %m%n

 ## \u4FDD\u5B58\u5F02\u5E38\u4FE1\u606F\u5230\u5355\u72EC\u6587\u4EF6 ###
 log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
 log4j.appender.E.File = logs/api/error.log
 log4j.appender.E.DatePattern = '.'yyyyMMdd
 log4j.appender.E.Append = true
 log4j.appender.E.Threshold = ERROR
 log4j.appender.E.layout = org.apache.log4j.PatternLayout
 log4j.appender.E.encoding=UTF-8
 log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %p ] [ %l-%t:%r ] %m%n

 ## \u4FDD\u5B58\u5F02\u5E38\u4FE1\u606F\u5230\u5355\u72EC\u6587\u4EF6 ###
 log4j.appender.F = org.apache.log4j.DailyRollingFileAppender
 log4j.appender.F.File = logs/api/debug.log
 log4j.appender.F.DatePattern = '.'yyyyMMdd
 log4j.appender.F.Append = true
 log4j.appender.F.Threshold = DEBUG
 log4j.appender.F.layout = org.apache.log4j.PatternLayout
 log4j.appender.F.encoding=UTF-8
 log4j.appender.F.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %p ] [ %l-%t:%r ] %m%n

测试结果：

邮件实际收到的内容：

为了保证以后的兼容性，本例采用了工厂设计模式，有什么不正确的或需要改进的，请各位批评指导，谢谢！

附：项目结构图