JavaMail教程(三)-接收邮件
1.接收邮件
1.1使用POP3接收邮件
1.1.1输出收件箱信息
package org.ygy.demo;
import java.util.Properties;
import javax.mail.Folder;
import javax.mail.MessagingException;
import javax.mail.NoSuchProviderException;
import javax.mail.Session;
import javax.mail.Store;
public class ReceiveMail {
public static final String HOST = "pop.126.com";//服务器地址
public static final String PROTOCOL = "pop3";//协议
public static final String PORT = "110";//pop默认端口为110
public static final String USER = "[email protected]";//账户
public static final String PASSWORD = "xxx"; //密码
/**
* 输出收件箱的基本信息
*/
public void displayFolderInfo() {
Properties props = new Properties();
props.put("mail.pop3.host", ReceiveMail.HOST);//设置服务器地址
props.put("mail.store.protocol" , ReceiveMail.PROTOCOL);//设置协议
props.put("mail.pop3.port", "110");//设置端口
Session session = Session.getDefaultInstance(props);
Store store = null;
Folder folder = null;
try {
store = session.getStore();
store.connect(HOST , USER , PASSWORD);
/*
* POP3 supports only a single folder named "INBOX".
* POP协议的话，这里只能是INBOX
*/
folder = store.getFolder("INBOX");
folder.open(Folder.READ_ONLY);//以只读方式打开收件箱
System.out.println("邮件总数：" + folder.getMessageCount());
//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("新邮件数：" + folder.getNewMessageCount());
} catch (NoSuchProviderException e) {
e.printStackTrace();
} catch (MessagingException e) {
e.printStackTrace();
} finally {
try {
folder.close(false);
store.close();
} catch (MessagingException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) {
ReceiveMail receive = new ReceiveMail();
receive.displayFolderInfo();
}
}
结果显示如下图：
这时，你可以通过浏览器登录“126邮箱”删除几封邮件，再运行测试一下，数据都是正确的。126邮箱默认都打开了POP/SMTP功能，可以设置的。
注：126邮箱比较好用，之前使用QQ邮箱时，获取的”邮件总数“总是不对，结果显示只有16封，但是用浏览器登录QQ邮箱，可以看到一共有200多封，不知道还需要设置什么
。输出邮件内容之后，发现好像只有2013年的，
。
1.1.2输出邮件信息
package org.ygy.demo; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; 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.NoSuchProviderException; 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; public class ReceiveMail { public static final String HOST = "pop.126.com";//服务器地址 public static final String PROTOCOL = "pop3";//协议 public static final String PORT = "110";//pop默认端口为110 public static final String USER = "[email protected]";//账户 public static final String PASSWORD = "xxx"; //密码 public static final String DEFAULT_PATTERN = "yyyy年MM月dd日 E HH:mm"; public static Session session = null; /** * 输出收件箱的基本信息 */ public void displayFolderInfo() { Session session = getSession(); Store store = null; Folder folder = null; try { store = session.getStore(); store.connect(HOST , USER , PASSWORD); /* * POP3 supports only a single folder named "INBOX". * POP协议的话，这里只能是INBOX */ folder = store.getFolder("INBOX"); folder.open(Folder.READ_ONLY);//以只读方式打开收件箱 System.out.println("邮件总数：" + folder.getMessageCount()); //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("新邮件数：" + folder.getNewMessageCount()); } catch (NoSuchProviderException e) { e.printStackTrace(); } catch (MessagingException e) { e.printStackTrace(); } finally { try { folder.close(false); store.close(); } catch (MessagingException e) { e.printStackTrace(); } } } /** * 获取Session * @return */ public static Session getSession() { if(session == null) { Properties props = new Properties(); props.put("mail.pop3.host", ReceiveMail.HOST);//设置服务器地址 props.put("mail.store.protocol" , ReceiveMail.PROTOCOL);//设置协议 props.put("mail.pop3.port", "110");//设置端口 session = Session.getDefaultInstance(props); } return session; } /** * 输出邮件的信息 */ public void displayMessageInfo() { Session session = getSession(); Store store = null; Folder folder = null; try { store = session.getStore(); store.connect(HOST , USER , PASSWORD); folder = store.getFolder("INBOX");//POP协议的话，这里只能是INBOX folder.open(Folder.READ_ONLY);//以只读方式打开收件箱 parseMessages(folder.getMessages()); } catch (NoSuchProviderException e) { e.printStackTrace(); } catch (MessagingException e) { e.printStackTrace(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { folder.close(false); store.close(); } catch (MessagingException e) { e.printStackTrace(); } } } /** * 解析邮件 * @param messages * @throws MessagingException * @throws IOException */ public void parseMessages(Message[] messages) throws MessagingException, IOException { if(messages.length < 1 || messages == null) { System.out.println("没有邮件"); } else { for(int i = 0; i < messages.length; i++) { MimeMessage each = (MimeMessage) messages[i]; System.out.println("------------------解析第" + each.getMessageNumber() + "封邮件-------------------- "); System.out.println("主题: " + getSubject(each)); System.out.println("发件人: " + getFrom(each)); System.out.println("收件人：" + getReceiveAddress(each, null)); System.out.println("发送时间：" + getSentDate(each, ReceiveMail.DEFAULT_PATTERN)); System.out.println("是否已读：" + isSeen(each)); System.out.println("邮件优先级：" + getPriority(each)); System.out.println("是否需要回执：" + isReplySign(each)); System.out.println("邮件大小：" + each.getSize() + "b"); boolean isContainerAttachment = isContainAttachment(each); System.out.println("是否包含附件：" + isContainerAttachment); if (isContainerAttachment) { saveAttachment(each, "F:\\mailtmp\\"+each.getSubject() + "_"); //保存附件 } StringBuffer content = new StringBuffer(30); getMailTextContent(each, content); System.out.println("邮件正文：" + (content.length() > 100 ? content.substring(0,100) + "..." : content)); System.out.println("------------------第" + each.getMessageNumber() + "封邮件解析结束-------------------- "); System.out.println(); } } } /** * 获取邮件文本内容 * @param part 邮件体 * @param content 存储邮件文本内容的字符串 * @throws MessagingException * @throws IOException */ private 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 IOException */ private void saveAttachment(Part part, String destDir) throws UnsupportedEncodingException, MessagingException, 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 destDir 文件名 * @param fileName 文件存储目录 * @throws IOException */ private void saveFile(InputStream is, String destDir, String fileName) throws 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 */ private String decodeText(String encodeText) throws UnsupportedEncodingException { if (encodeText == null || "".equals(encodeText)) { return ""; } else { return MimeUtility.decodeText(encodeText); } } /** * 判断邮件中是否包含附件 * @param part 邮件 * @return 邮件中存在附件返回true，不存在返回false * @throws MessagingException * @throws IOException */ private 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; } /** * 判断邮件是否需要回执 * @param msg 邮件 * @return 需要回执返回true,否则返回false * @throws MessagingException */ private 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 * @return 1(High):紧急 3:普通(Normal) 5:低(Low) * @throws MessagingException */ private 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; } /** * 判断邮件是否已读（使用POP3的话，这里应该都是未读） * @param msg 邮件 * @return 已读-true；未读-false * @throws MessagingException */ private boolean isSeen(MimeMessage msg) throws MessagingException { return msg.getFlags().contains(Flags.Flag.SEEN); } /** * 获取邮件发送时间 * @param msg 邮件 * @param pattern 日期格式 * @return * @throws MessagingException */ private String getSentDate(MimeMessage msg, String pattern) throws MessagingException { String sentDate = ""; Date receivedDate = msg.getSentDate(); if(receivedDate != null) { sentDate = new SimpleDateFormat(pattern).format(receivedDate); } else { sentDate = "没有邮件发送时间!"; } return sentDate; } /** * 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 * @param msg 邮件 * @param type 收件人类型 * Message.RecipientType.TO 收件人 * Message.RecipientType.CC 抄送 * Message.RecipientType.BCC 密送 * @return * @throws MessagingException */ private 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) { receiveAddress.append("没有收件人"); } else { 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(); } /** * 获取发件人 * @param msg 邮件 * @return 姓名 <邮箱地址> * @throws MessagingException * @throws UnsupportedEncodingException */ private String getFrom(MimeMessage msg) throws MessagingException, UnsupportedEncodingException { Address[] froms = msg.getFrom(); StringBuilder from = new StringBuilder(""); if (froms.length < 1) { from.append("没有收件人"); } else { InternetAddress address = (InternetAddress) froms[0]; from.append((address.getPersonal() == null)? "" : MimeUtility.decodeText(address.getPersonal())); from.append(" <").append(address.getAddress()).append(">"); } return from.toString(); } /** * 获得邮件主题 * @param msg 邮件 * @return 解码后的邮件主题 * @throws UnsupportedEncodingException * @throws MessagingException */ private String getSubject(MimeMessage msg) throws UnsupportedEncodingException, MessagingException { return MimeUtility.decodeText(msg.getSubject()); } public static void main(String[] args) { ReceiveMail receive = new ReceiveMail(); receive.displayFolderInfo(); receive.displayMessageInfo(); } }
邮件的附件部分没有仔细研究，代码是从下面的参考文章学习的。
2.参考文章
JavaMail学习笔记（一）、理解邮件传输协议（SMTP、POP3、IMAP、MIME）
JavaMail学习笔记（二）、JavaMail API简介和配置开发环境
JavaMail学习笔记（三）、使用SMTP协议发送电子邮件（全）
JavaMail学习笔记（四）、使用POP3协议接收并解析电子邮件（全）
JavaMail学习笔记（五）、使用IMAP协议接收并解析电子邮件
JavaMail学习笔记（六）、搜索邮件