JavaMail系列(四) 使用POP3协议接收并解析电子邮件

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  www.2cto.com
     * @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：

 

原文链接：http://www.2cto.com/kf/201206/136651.html