利用JavaMail實現郵件的收取
阿新 • • 發佈：2018-12-24
昨天寫了一個利用JavaMail傳送郵件的示例，本著有始有終的原則。今天寫了一篇利用JavaMail收取郵件的示例。由於實力有限，程式碼寫的不周到的地方，請大家見亮。本人只是寫了一個簡單的例子，在實際專案開發中，還有很多東西需要讀者自己去斟酌和修改。廢話不多說，直接上程式碼。
1、一些引數配置的常量類
package com.bao.receivemail; /** * 郵件配置的常量類 */ public class Config { public static String MAIL_HOST = "pop3.163.com";//伺服器ip public static int MAIL_PORT = 110;//埠 public static String MAIL_TYPE = "pop3";//服務型別 public static String MAIL_AUTH = "true"; public static String MAIL_ATTACH_PATH = "upload/recMail/";//附件存放目錄 }
2、郵件的收取類
package com.bao.receivemail; 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.Properties; import javax.mail.BodyPart; 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; import com.sun.mail.pop3.POP3Message; /** * 郵件的收取類 */ public class ReceiveMailHandler { /** * 獲取session會話的方法 * @return * @throws Exception */ private Session getSessionMail() throws Exception { Properties properties = System.getProperties(); properties.put("mail.smtp.host", Config.MAIL_HOST); properties.put("mail.smtp.auth", Config.MAIL_AUTH); Session sessionMail = Session.getDefaultInstance(properties, null); return sessionMail; } /** * 接收郵件 * @param 郵箱的使用者名稱和密碼 * @return 無 */ public void receiveMail(String userName,String passWord) { Store store = null; Folder folder = null; int messageCount = 0; URLName urln = null; try{ //進行使用者郵箱連線 urln = new URLName(Config.MAIL_TYPE, Config.MAIL_HOST, Config.MAIL_PORT, null,userName,passWord); store = getSessionMail().getStore(urln); store.connect(); //獲得郵箱內的郵件夾Folder物件，以"只讀"開啟 folder = store.getFolder("INBOX");//開啟收件箱 folder.open(Folder.READ_ONLY);//設定只讀 //獲得郵件夾Folder內的所有郵件個數 messageCount = folder.getMessageCount();// 獲取所有郵件個數 //獲取新郵件處理 System.out.println("============>>郵件總數："+messageCount); if(messageCount > 0){ Message[] messages = folder.getMessages(messageCount,messageCount);//讀取最近的一封郵件 for(int i = 0;i < messages.length;i++) { String content = getMailContent((Part)messages[i]);//獲取內容 if (isContainAttach((Part)messages[i])) { saveAttachMent((Part)messages[i],Config.MAIL_ATTACH_PATH); } System.out.println("=====================>>開始顯示郵件內容<<====================="); System.out.println("傳送人: " + getFrom(messages[i])); System.out.println("主題: " + getSubject(messages[i])); System.out.println("內容: " + content); System.out.println("傳送時間: " + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(((MimeMessage) messages[i]).getSentDate())); System.out.println("是否有附件: " + (isContainAttach((Part)messages[i]) ? "有附件" : "無附件")); System.out.println("=====================>>結束顯示郵件內容<<====================="); ((POP3Message) messages[i]).invalidate(true); } } }catch(Exception e){ e.printStackTrace(); }finally{ if(folder != null && folder.isOpen()){ try { folder.close(true); } catch (MessagingException e) { e.printStackTrace(); } } if(store.isConnected()){ try { store.close(); } catch (MessagingException e) { e.printStackTrace(); } } } } /** * 獲得發件人的地址 * @param message：Message * @return 發件人的地址 */ private String getFrom(Message message) throws Exception { InternetAddress[] address = (InternetAddress[]) ((MimeMessage) message).getFrom(); String from = address[0].getAddress(); if (from == null){ from = ""; } return from; } /** * 獲得郵件主題 * @param message：Message * @return 郵件主題 */ private String getSubject(Message message) throws Exception { String subject = ""; if(((MimeMessage) message).getSubject() != null){ subject = MimeUtility.decodeText(((MimeMessage) message).getSubject());// 將郵件主題解碼 } return subject; } /** * 獲取郵件內容 * @param part：Part */ private String getMailContent(Part part) throws Exception { StringBuffer bodytext = new StringBuffer();//存放郵件內容 //判斷郵件型別,不同型別操作不同 if (part.isMimeType("text/plain")) { bodytext.append((String) part.getContent()); } else if (part.isMimeType("text/html")) { 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 {} return bodytext.toString(); } /** * 判斷此郵件是否包含附件 * @param part：Part * @return 是否包含附件 */ private boolean isContainAttach(Part part) throws Exception { boolean attachflag = false; 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; } /** * 儲存附件 * @param part：Part * @param filePath：郵件附件存放路徑 */ private void saveAttachMent(Part part,String filePath) throws Exception { String fileName = ""; //儲存附件到伺服器本地 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 != null) { fileName = MimeUtility.decodeText(fileName); saveFile(fileName, mpart.getInputStream(),filePath); } } else if (mpart.isMimeType("multipart/*")) { saveAttachMent(mpart,filePath); } else { fileName = mpart.getFileName(); if (fileName != null) { fileName = MimeUtility.decodeText(fileName); saveFile(fileName, mpart.getInputStream(),filePath); } } } } else if (part.isMimeType("message/rfc822")) { saveAttachMent((Part) part.getContent(),filePath); } } /** * 儲存附件到指定目錄裡 * @param fileName：附件名稱 * @param in：檔案輸入流 * @param filePath：郵件附件存放基路徑 */ private void saveFile(String fileName, InputStream in,String filePath) throws Exception { File storefile = new File(filePath); if(!storefile.exists()){ storefile.mkdirs(); } BufferedOutputStream bos = null; BufferedInputStream bis = null; try { bos = new BufferedOutputStream(new FileOutputStream(filePath + "\\" + fileName)); bis = new BufferedInputStream(in); int c; while ((c = bis.read()) != -1) { bos.write(c); bos.flush(); } } catch (Exception e) { throw e; } finally { if(bos != null){ bos.close(); } if(bis != null){ bis.close(); } } } }
3、測試程式
package com.bao.main; import com.bao.receivemail.ReceiveMailHandler; public class Main { public static void main(String[] args) { try { new ReceiveMailHandler().receiveMail("username", "password"); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
執行結果會在控制檯打印出來，只讀取了郵箱中最新的那一封郵件。如果有附件，附件會自動儲存到專案中你設定的檔案目錄中。程式不上傳了，大家自己看下吧！謝謝大家的支援^.^！