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

### u8F93u51FAu5230u63A7u5236u53F0 ###
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

## u8F93u51FAu5230u65E5u5FD7u6587u4EF6 ###
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

## u4FDDu5B58u5F02u5E38u4FE1u606Fu5230u5355u72ECu6587u4EF6 ###
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

## u4FDDu5B58u5F02u5E38u4FE1u606Fu5230u5355u72ECu6587u4EF6 ###
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