JavaMail学习笔记（四）、使用POP3协议接收并解析电子邮件（全）

package org.yangxin.study.jm;

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

import javax.mail.Address;
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.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.internet.MimeUtility;

/**
 * 使用POP3协议接收邮件
 */
public class POP3ReceiveMailTest {
 
 public static void main(String[] args) throws Exception {
  receive();
 }
 
 /**
  * 接收邮件
  */
 public static void receive() throws Exception {
  // 准备连接服务器的会话信息
  Properties props = new Properties();
  props.setProperty("mail.store.protocol", "pop3");  // 协议
  props.setProperty("mail.pop3.port", "110");    // 端口
  props.setProperty("mail.pop3.host", "pop3.163.com"); // pop3服务器
  
  // 创建Session实例对象
  Session session = Session.getInstance(props);
  Store store = session.getStore("pop3");
  store.connect("[e-mail]", "123456abc");
  
  // 获得收件箱
  Folder folder = store.getFolder("INBOX");
  /* Folder.READ_ONLY：只读权限
   * Folder.READ_WRITE：可读可写（可以修改邮件的状态）
   */
  folder.open(Folder.READ_WRITE); //打开收件箱
  
  // 由于POP3协议无法获知邮件的状态,所以getUnreadMessageCount得到的是收件箱的邮件总数
  System.out.println("未读邮件数: " + folder.getUnreadMessageCount());
  
  // 由于POP3协议无法获知邮件的状态,所以下面得到的结果始终都是为0
  System.out.println("删除邮件数: " + folder.getDeletedMessageCount());
  System.out.println("新邮件: " + folder.getNewMessageCount());
  
  // 获得收件箱中的邮件总数
  System.out.println("邮件总数: " + folder.getMessageCount());
  
  // 得到收件箱中的所有邮件,并解析
  Message[] messages = folder.getMessages();
  parseMessage(messages);
  
  //释放资源
  folder.close(true);
  store.close();
 }
 
 /**
  * 解析邮件
  * @param messages 要解析的邮件列表
  */
 public static void parseMessage(Message ...messages) throws MessagingException, IOException {
  if (messages == null || messages.length < 1) 
   throw new MessagingException("未找到要解析的邮件!");
  
  // 解析所有邮件
  for (int i = 0, count = messages.length; i < count; i++) {
   MimeMessage msg = (MimeMessage) messages[i];
   System.out.println("------------------解析第" + msg.getMessageNumber() + "封邮件-------------------- ");
   System.out.println("主题: " + getSubject(msg));
   System.out.println("发件人: " + getFrom(msg));
   System.out.println("收件人：" + getReceiveAddress(msg, null));
   System.out.println("发送时间：" + getSentDate(msg, null));
   System.out.println("是否已读：" + isSeen(msg));
   System.out.println("邮件优先级：" + getPriority(msg));
   System.out.println("是否需要回执：" + isReplySign(msg));
   System.out.println("邮件大小：" + msg.getSize() * 1024 + "kb");
   boolean isContainerAttachment = isContainAttachment(msg);
   System.out.println("是否包含附件：" + isContainerAttachment);
   if (isContainerAttachment) {
    saveAttachment(msg, "c:\\mailtmp\\"+msg.getSubject() + "_"); //保存附件
   } 
   StringBuffer content = new StringBuffer(30);
   getMailTextContent(msg, content);
   System.out.println("邮件正文：" + (content.length() > 100 ? content.substring(0,100) + "..." : content));
   System.out.println("------------------第" + msg.getMessageNumber() + "封邮件解析结束-------------------- ");
   System.out.println();
  }
 }
 
 /**
  * 获得邮件主题
  * @param msg 邮件内容
  * @return 解码后的邮件主题
  */
 public static String getSubject(MimeMessage msg) throws UnsupportedEncodingException, MessagingException {
  return MimeUtility.decodeText(msg.getSubject());
 }
 
 /**
  * 获得邮件发件人
  * @param msg 邮件内容
  * @return 姓名 <Email地址>
  * @throws MessagingException
  * @throws UnsupportedEncodingException 
  */
 public static String getFrom(MimeMessage msg) throws MessagingException, UnsupportedEncodingException {
  String from = "";
  Address[] froms = msg.getFrom();
  if (froms.length < 1)
   throw new MessagingException("没有发件人!");
  
  InternetAddress address = (InternetAddress) froms[0];
  String person = address.getPersonal();
  if (person != null) {
   person = MimeUtility.decodeText(person) + " ";
  } else {
   person = "";
  }
  from = person + "<" + address.getAddress() + ">";
  
  return from;
 }
 
 /**
  * 根据收件人类型，获取邮件收件人、抄送和密送地址。如果收件人类型为空，则获得所有的收件人
  * <p>Message.RecipientType.TO  收件人</p>
  * <p>Message.RecipientType.CC  抄送</p>
  * <p>Message.RecipientType.BCC 密送</p>
  * @param msg 邮件内容
  * @param type 收件人类型
  * @return 收件人1 <邮件地址1>, 收件人2 <邮件地址2>, ...
  * @throws MessagingException
  */
 public static String getReceiveAddress(MimeMessage msg, Message.RecipientType type) throws MessagingException {
  StringBuffer receiveAddress = new StringBuffer();
  Address[] addresss = null;
  if (type == null) {
   addresss = msg.getAllRecipients();
  } else {
   addresss = msg.getRecipients(type);
  }
  
  if (addresss == null || addresss.length < 1)
   throw new MessagingException("没有收件人!");
  for (Address address : addresss) {
   InternetAddress internetAddress = (InternetAddress)address;
   receiveAddress.append(internetAddress.toUnicodeString()).append(",");
  }
  
  receiveAddress.deleteCharAt(receiveAddress.length()-1); //删除最后一个逗号
  
  return receiveAddress.toString();
 }
 
 /**
  * 获得邮件发送时间
  * @param msg 邮件内容
  * @return yyyy年mm月dd日 星期X HH:mm
  * @throws MessagingException
  */
 public static String getSentDate(MimeMessage msg, String pattern) throws MessagingException {
  Date receivedDate = msg.getSentDate();
  if (receivedDate == null)
   return "";
  
  if (pattern == null || "".equals(pattern))
   pattern = "yyyy年MM月dd日 E HH:mm ";
  
  return new SimpleDateFormat(pattern).format(receivedDate);
 }
 
 /**
  * 判断邮件中是否包含附件
  * @param msg 邮件内容
  * @return 邮件中存在附件返回true，不存在返回false
  * @throws MessagingException
  * @throws IOException
  */
 public static boolean isContainAttachment(Part part) throws MessagingException, IOException {
  boolean flag = false;
  if (part.isMimeType("multipart/*")) {
   MimeMultipart multipart = (MimeMultipart) part.getContent();
   int partCount = multipart.getCount();
   for (int i = 0; i < partCount; i++) {
    BodyPart bodyPart = multipart.getBodyPart(i);
    String disp = bodyPart.getDisposition();
    if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
     flag = true;
    } else if (bodyPart.isMimeType("multipart/*")) {
     flag = isContainAttachment(bodyPart);
    } else {
     String contentType = bodyPart.getContentType();
     if (contentType.indexOf("application") != -1) {
      flag = true;
     }  
     
     if (contentType.indexOf("name") != -1) {
      flag = true;
     } 
    }
    
    if (flag) break;
   }
  } else if (part.isMimeType("message/rfc822")) {
   flag = isContainAttachment((Part)part.getContent());
  }
  return flag;
 }
 
 /**
  * 判断邮件是否已读
  * @param msg 邮件内容
  * @return 如果邮件已读返回true,否则返回false
  * @throws MessagingException 
  */
 public static boolean isSeen(MimeMessage msg) throws MessagingException {
  return msg.getFlags().contains(Flags.Flag.SEEN);
 }
 
 /**
  * 判断邮件是否需要阅读回执
  * @param msg 邮件内容
  * @return 需要回执返回true,否则返回false
  * @throws MessagingException
  */
 public static boolean isReplySign(MimeMessage msg) throws MessagingException {
  boolean replySign = false;
  String[] headers = msg.getHeader("Disposition-Notification-To");
  if (headers != null)
   replySign = true;
  return replySign;
 }
 
 /**
  * 获得邮件的优先级
  * @param msg 邮件内容
  * @return 1(High):紧急  3:普通(Normal)  5:低(Low)
  * @throws MessagingException 
  */
 public static String getPriority(MimeMessage msg) throws MessagingException {
  String priority = "普通";
  String[] headers = msg.getHeader("X-Priority");
  if (headers != null) {
   String headerPriority = headers[0];
   if (headerPriority.indexOf("1") != -1 || headerPriority.indexOf("High") != -1)
    priority = "紧急";
   else if (headerPriority.indexOf("5") != -1 || headerPriority.indexOf("Low") != -1)
    priority = "低";
   else
    priority = "普通";
  }
  return priority;
 } 
 
 /**
  * 获得邮件文本内容
  * @param part 邮件体
  * @param content 存储邮件文本内容的字符串
  * @throws MessagingException
  * @throws IOException
  */
 public static void getMailTextContent(Part part, StringBuffer content) throws MessagingException, IOException {
  //如果是文本类型的附件，通过getContent方法可以取到文本内容，但这不是我们需要的结果，所以在这里要做判断
  boolean isContainTextAttach = part.getContentType().indexOf("name") > 0; 
  if (part.isMimeType("text/*") && !isContainTextAttach) {
   content.append(part.getContent().toString());
  } else if (part.isMimeType("message/rfc822")) { 
   getMailTextContent((Part)part.getContent(),content);
  } else if (part.isMimeType("multipart/*")) {
   Multipart multipart = (Multipart) part.getContent();
   int partCount = multipart.getCount();
   for (int i = 0; i < partCount; i++) {
    BodyPart bodyPart = multipart.getBodyPart(i);
    getMailTextContent(bodyPart,content);
   }
  }
 }
 
 /**
  * 保存附件
  * @param part 邮件中多个组合体中的其中一个组合体
  * @param destDir  附件保存目录
  * @throws UnsupportedEncodingException
  * @throws MessagingException
  * @throws FileNotFoundException
  * @throws IOException
  */
 public static void saveAttachment(Part part, String destDir) throws UnsupportedEncodingException, MessagingException,
   FileNotFoundException, IOException {
  if (part.isMimeType("multipart/*")) {
   Multipart multipart = (Multipart) part.getContent(); //复杂体邮件
   //复杂体邮件包含多个邮件体
   int partCount = multipart.getCount();
   for (int i = 0; i < partCount; i++) {
    //获得复杂体邮件中其中一个邮件体
    BodyPart bodyPart = multipart.getBodyPart(i);
    //某一个邮件体也有可能是由多个邮件体组成的复杂体
    String disp = bodyPart.getDisposition();
    if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
     InputStream is = bodyPart.getInputStream();
     saveFile(is, destDir, decodeText(bodyPart.getFileName()));
    } else if (bodyPart.isMimeType("multipart/*")) {
     saveAttachment(bodyPart,destDir);
    } else {
     String contentType = bodyPart.getContentType();
     if (contentType.indexOf("name") != -1 || contentType.indexOf("application") != -1) {
      saveFile(bodyPart.getInputStream(), destDir, decodeText(bodyPart.getFileName()));
     }
    }
   }
  } else if (part.isMimeType("message/rfc822")) {
   saveAttachment((Part) part.getContent(),destDir);
  }
 }
 
 /**
  * 读取输入流中的数据保存至指定目录
  * @param is 输入流
  * @param fileName 文件名
  * @param destDir 文件存储目录
  * @throws FileNotFoundException
  * @throws IOException
  */
 private static void saveFile(InputStream is, String destDir, String fileName)
   throws FileNotFoundException, IOException {
  BufferedInputStream bis = new BufferedInputStream(is);
  BufferedOutputStream bos = new BufferedOutputStream(
    new FileOutputStream(new File(destDir + fileName)));
  int len = -1;
  while ((len = bis.read()) != -1) {
   bos.write(len);
   bos.flush();
  }
  bos.close();
  bis.close();
 }
 
 /**
  * 文本解码
  * @param encodeText 解码MimeUtility.encodeText(String text)方法编码后的文本
  * @return 解码后的文本
  * @throws UnsupportedEncodingException
  */
 public static String decodeText(String encodeText) throws UnsupportedEncodingException {
  if (encodeText == null || "".equals(encodeText)) {
   return "";
  } else {
   return MimeUtility.decodeText(encodeText);
  }
 }
}

 

 

 

测试结果：

 

 

 

转自：http://blog.csdn.net/xyang81/article/details/7675160