java接收邮件的探索之旅

场景：目前需要定时收取某个账户的未读邮件，保存到elasticsearch doc中去。

使用javaMail收邮件主要有两种协议，一种是pop3，一种是imap。这两种协议都可以用来收邮件，但是在其中的处理上是有区别的。pop3是不支持判断邮件是否为已读的，也就是说你不能直接从收件箱里面取到未读邮件，这需要自己进行判断，然而imap就提供了这样的功能，使用imap时可以很轻松的判断该邮件是否为已读或未读或其他。
由此看来，pop3不适合我的需求【通过每次检索全部，然后判断subject也可以实现，不过每次都需要遍历对比，比较麻烦】
那么我就用imap协议来收取了，pop3和imap只是配置email的url有点区别 其他地方是一样的

pop3和imap主要区别就是能否判断邮件状态的问题，其他的操作都差不多.

准备工作：

邮箱设置打开pop3、imap、smtp收发协议

去你的126|163|qq邮箱 打开设置-pop3 如图
注意重点：

• 全部接收，不然30天以前的收不到还以为代码有问题
• 配置授权码，目前163和qq邮箱都是授权码形式，代码里的password位置填写的都是授权码而不是邮箱密码哦
  

  协议的端口和协议规则

  //协议的内容端口等区别，对应关系如图：
  

具体的实现代码

package cn.northpark.utils;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;

import javax.mail.BodyPart;
import javax.mail.Flags;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Part;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.URLName;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeUtility;   
  
/**  
* @author github.com/liuhouer
* @有一封邮件就需要建立一个ReciveMail对象  
*/  
public class MailReceive {   
    private MimeMessage mimeMessage = null;   
    private String saveAttachPath = ""; //附件下载后的存放目录   
    private StringBuffer bodytext = new StringBuffer();//存放邮件内容   
    private String dateformat = "yy-MM-dd HH:mm"; //默认的日前显示格式   
  
    public MailReceive(MimeMessage mimeMessage) {   
        this.mimeMessage = mimeMessage;   
    }   
  
    public void setMimeMessage(MimeMessage mimeMessage) {   
        this.mimeMessage = mimeMessage;   
    }   
  
    /**  
     * 获得发件人的地址和姓名  
     */  
    public String getFrom() throws Exception {   
        InternetAddress address[] = (InternetAddress[]) mimeMessage.getFrom();   
        String from = address[0].getAddress();   
        if (from == null)   
            from = "";   
        String personal = address[0].getPersonal();   
        if (personal == null)   
            personal = "";   
        String fromaddr = personal + "<" + from + ">";   
        return fromaddr;   
    }   
  
    /**  
     * 获得邮件的收件人，抄送，和密送的地址和姓名，根据所传递的参数的不同 "to"----收件人 "cc"---抄送人地址 "bcc"---密送人地址  
     */  
    public String getMailAddress(String type) throws Exception {   
        String mailaddr = "";   
        String addtype = type.toUpperCase();   
        InternetAddress[] address = null;   
        if (addtype.equals("TO") || addtype.equals("CC")|| addtype.equals("BCC")) {   
            if (addtype.equals("TO")) {   
                address = (InternetAddress[]) mimeMessage.getRecipients(Message.RecipientType.TO);   
            } else if (addtype.equals("CC")) {   
                address = (InternetAddress[]) mimeMessage.getRecipients(Message.RecipientType.CC);   
            } else {   
                address = (InternetAddress[]) mimeMessage.getRecipients(Message.RecipientType.BCC);   
            }   
            if (address != null) {   
                for (int i = 0; i < address.length; i++) {   
                    String email = address[i].getAddress();   
                    if (email == null)   
                        email = "";   
                    else {   
                        email = MimeUtility.decodeText(email);   
                    }   
                    String personal = address[i].getPersonal();   
                    if (personal == null)   
                        personal = "";   
                    else {   
                        personal = MimeUtility.decodeText(personal);   
                    }   
                    String compositeto = personal + "<" + email + ">";   
                    mailaddr += "," + compositeto;   
                }   
                mailaddr = mailaddr.substring(1);   
            }   
        } else {   
            throw new Exception("Error emailaddr type!");   
        }   
        return mailaddr;   
    }   
  
    /**  
     * 获得邮件主题  
     */  
    public String getSubject() throws MessagingException {   
        String subject = "";   
        try {   
            subject = MimeUtility.decodeText(mimeMessage.getSubject());   
            if (subject == null)   
                subject = "";   
        } catch (Exception exce) {}   
        return subject;   
    }   
  
    /**  
     * 获得邮件发送日期  
     */  
    public String getSentDate() throws Exception {   
        Date sentdate = mimeMessage.getSentDate();   
        SimpleDateFormat format = new SimpleDateFormat(dateformat);   
        return format.format(sentdate);   
    }   
  
    /**  
     * 获得邮件正文内容  
     */  
    public String getBodyText() {   
        return bodytext.toString();   
    }   
  
    /**  
     * 解析邮件，把得到的邮件内容保存到一个StringBuffer对象中，解析邮件 主要是根据MimeType类型的不同执行不同的操作，一步一步的解析  
     */  
    public void getMailContent(Part part) throws Exception {   
        String contenttype = part.getContentType();   
        int nameindex = contenttype.indexOf("name");   
        boolean conname = false;   
        if (nameindex != -1)   
            conname = true;   
        System.out.println("CONTENTTYPE: " + contenttype);   
        if (part.isMimeType("text/plain") && !conname) {   
            bodytext.append((String) part.getContent());   
        } else if (part.isMimeType("text/html") && !conname) {   
            bodytext.append((String) part.getContent());   
        } else if (part.isMimeType("multipart/*")) {   
            Multipart multipart = (Multipart) part.getContent();   
            int counts = multipart.getCount();   
            for (int i = 0; i < counts; i++) {   
                getMailContent(multipart.getBodyPart(i));   
            }   
        } else if (part.isMimeType("message/rfc822")) {   
            getMailContent((Part) part.getContent());   
        } else {}   
    }   
  
    /**   
     * 判断此邮件是否需要回执，如果需要回执返回"true",否则返回"false"  
     */   
    public boolean getReplySign() throws MessagingException {   
        boolean replysign = false;   
        String needreply[] = mimeMessage   
                .getHeader("Disposition-Notification-To");   
        if (needreply != null) {   
            replysign = true;   
        }   
        return replysign;   
    }   
  
    /**  
     * 获得此邮件的Message-ID  
     */  
    public String getMessageId() throws MessagingException {   
        return mimeMessage.getMessageID();   
    }   
  
    /**  
     * 【判断此邮件是否已读，如果已读返回false,未读返回true】  
     */  
    public boolean isNew() throws MessagingException {   
        boolean isnew = true;   
        Flags flags = ((Message) mimeMessage).getFlags();   
        Flags.Flag[] flag = flags.getSystemFlags();   
        System.out.println("flags's length: " + flag.length);   
        for (int i = 0; i < flag.length; i++) {   
            if (flag[i] == Flags.Flag.SEEN) {   
                isnew = false;   
                System.out.println("seen Message.......");   
                break;   
            }   
        }   
        return isnew;   
    }   
  
    /**  
     * 判断此邮件是否包含附件  
     */  
    public boolean isContainAttach(Part part) throws Exception {   
        boolean attachflag = false;   
        String contentType = part.getContentType();   
        if (part.isMimeType("multipart/*")) {   
            Multipart mp = (Multipart) part.getContent();   
            for (int i = 0; i < mp.getCount(); i++) {   
                BodyPart mpart = mp.getBodyPart(i);   
                String disposition = mpart.getDisposition();   
                if ((disposition != null)   
                        && ((disposition.equals(Part.ATTACHMENT)) || (disposition   
                                .equals(Part.INLINE))))   
                    attachflag = true;   
                else if (mpart.isMimeType("multipart/*")) {   
                    attachflag = isContainAttach((Part) mpart);   
                } else {   
                    String contype = mpart.getContentType();   
                    if (contype.toLowerCase().indexOf("application") != -1)   
                        attachflag = true;   
                    if (contype.toLowerCase().indexOf("name") != -1)   
                        attachflag = true;   
                }   
            }   
        } else if (part.isMimeType("message/rfc822")) {   
            attachflag = isContainAttach((Part) part.getContent());   
        }   
        return attachflag;   
    }   
  
    /**   
     * 【保存附件】   
     */   
    public void saveAttachMent(Part part) throws Exception {   
        String fileName = "";   
        if (part.isMimeType("multipart/*")) {   
            Multipart mp = (Multipart) part.getContent();   
            for (int i = 0; i < mp.getCount(); i++) {   
                BodyPart mpart = mp.getBodyPart(i);   
                String disposition = mpart.getDisposition();   
                if ((disposition != null)   
                        && ((disposition.equals(Part.ATTACHMENT)) || (disposition   
                                .equals(Part.INLINE)))) {   
                    fileName = mpart.getFileName();   
                    if (fileName.toLowerCase().indexOf("gb2312") != -1) {   
                        fileName = MimeUtility.decodeText(fileName);   
                    }   
                    saveFile(fileName, mpart.getInputStream());   
                } else if (mpart.isMimeType("multipart/*")) {   
                    saveAttachMent(mpart);   
                } else {   
                    fileName = mpart.getFileName();   
                    if ((fileName != null)   
                            && (fileName.toLowerCase().indexOf("GB2312") != -1)) {   
                        fileName = MimeUtility.decodeText(fileName);   
                        saveFile(fileName, mpart.getInputStream());   
                    }   
                }   
            }   
        } else if (part.isMimeType("message/rfc822")) {   
            saveAttachMent((Part) part.getContent());   
        }   
    }   
  
    /**   
     * 【设置附件存放路径】   
     */   
  
    public void setAttachPath(String attachpath) {   
        this.saveAttachPath = attachpath;   
    }   
  
    /**  
     * 【设置日期显示格式】  
     */  
    public void setDateFormat(String format) throws Exception {   
        this.dateformat = format;   
    }   
  
    /**  
     * 【获得附件存放路径】  
     */  
    public String getAttachPath() {   
        return saveAttachPath;   
    }   
  
    /**  
     * 【真正的保存附件到指定目录里】  
     */  
    private void saveFile(String fileName, InputStream in) throws Exception {   
        String osName = System.getProperty("os.name");   
        String storedir = getAttachPath();   
        String separator = "";   
        if (osName == null)   
            osName = "";   
        if (osName.toLowerCase().indexOf("win") != -1) {   
            separator = "\\";  
            if (storedir == null || storedir.equals(""))  
                storedir = "c:\\tmp";  
        } else {  
            separator = "/";  
            storedir = "/tmp";  
        }  
        File storefile = new File(storedir + separator + fileName);  
        System.out.println("storefile's path: " + storefile.toString());  
        // for(int i=0;storefile.exists();i++){  
        // storefile = new File(storedir+separator+fileName+i);  
        // }  
        BufferedOutputStream bos = null;  
        BufferedInputStream bis = null;  
        try {  
            bos = new BufferedOutputStream(new FileOutputStream(storefile));  
            bis = new BufferedInputStream(in);  
            int c;  
            while ((c = bis.read()) != -1) {  
                bos.write(c);  
                bos.flush();  
            }  
        } catch (Exception exception) {  
            exception.printStackTrace();  
            throw new Exception("文件保存失败!");  
        } finally {  
            bos.close();  
            bis.close();  
        }  
    }  
    /**  
     * 测试收邮件代码  
     */  
    public static void main(String args[]) throws Exception {  
        
        
         Properties props = new Properties();

         props.setProperty("mail.smtp.host", "smtp.126.com");//指定服务器

         props.setProperty("mail.smtp.auth", "true");//指定需要验证

         Session session = Session.getDefaultInstance(props);
        
        
        
         
       //IMAP---------------------------------------------------------------------
         URLName urln = new URLName("imap", "imap.126.com", 143, null,  "用户名不还包含@126.com", "邮箱授权码");  
         
       //POP3---------------------------------------------------------
//        URLName urln = new URLName("pop3", "pop3.126.com", 110, null,  "test", "test");  

         Store store = session.getStore(urln);
         
         store.connect();
         
         
       Folder folder = store.getFolder("INBOX");  
       folder.open(Folder.READ_WRITE);  
       // 获取总邮件数      
       int total = folder.getMessageCount();      
       System.out.println("-----------------共有邮件：" + total  + " 封--------------");   
       // 得到收件箱文件夹信息，获取邮件列表      
       System.out.println("未读邮件数：" + folder.getUnreadMessageCount());      
       Message messages[] = folder.getMessages();  
       
       MailReceive pmm = null;  
       for (int i = 0; i < messages.length; i++) {  
           System.out.println("======================");  
           pmm = new MailReceive((MimeMessage) messages[i]);  
           System.out.println("邮件 " + i + " 未读？: " + pmm.isNew());  
           
           if(pmm.isNew()){
               // 获得邮件内容===============  
                pmm.getMailContent((Part) messages[i]);//把内容设置到bodytext
                   pmm.setAttachPath("d:\\");   
                   pmm.saveAttachMent((Part) messages[i]);
                System.out.println("Message " + i + " subject: " + pmm.getSubject());  
                System.out.println("Message " + i + " sentdate: "+ pmm.getSentDate());  
                System.out.println("Message " + i + " replysign: "+ pmm.getReplySign());  
                System.out.println("Message " + i + "  containAttachment: "+ pmm.isContainAttach((Part) messages[i]));  
                System.out.println("Message " + i + " form: " + pmm.getFrom());  
                System.out.println("Message " + i + " to: "+ pmm.getMailAddress("to"));  
                System.out.println("Message " + i + " cc: "+ pmm.getMailAddress("cc"));  
                System.out.println("Message " + i + " bcc: "+ pmm.getMailAddress("bcc"));  
                pmm.setDateFormat("yy年MM月dd日 HH:mm");  
                System.out.println("Message " + i + " sentdate: "+ pmm.getSentDate());  
                System.out.println("Message " + i + " Message-ID: "+ pmm.getMessageId());  
                System.out.println("Message " + i + " 内容: "+ pmm.getBodyText());
                
            
               //调接口存到es
           }
          
       }
    }   
}