用JavaMail发送和接收邮件

用JavaMail发送邮件

package com.mailsystem.example;

import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;

public class SendAttachment
...{
   public static void main(String[] args)
   ...{
       try
       ...{
           // 创建 properties ，里面包含了发送邮件服务器的地址。
           Properties mailProps = new Properties();
           mailProps.put("mail.smtp.host", "127.0.0.1");  

           // 创建 session
           Session mailSession = Session.getDefaultInstance(mailProps);

           // 创建 邮件的message，message对象包含了邮件众多有的部件，都是封装成了set方法去设置的
           MimeMessage message = new MimeMessage(mailSession);

           //设置发信人
           message.setFrom(new InternetAddress(
               "fred@testmail.com"));
           //收信人
           message.setRecipient(Message.RecipientType.TO,
               new InternetAddress("tang@testmail.com"));

           // 邮件标题
           message.setSubject("a poem");   


          //创建附件
           MimeMultipart multi = new MimeMultipart();

           // 创建 BodyPart，主要作用是将以后创建的n个内容加入MimeMultipart.也就是可以发n个附件

           BodyPart textBodyPart = new MimeBodyPart();  //第一个BodyPart.主要写一些一般的信件内容。

           textBodyPart.setText("Do you fear the force of the wind The slash of the rain Go face them and fight them "+
                   "Be savage again. Go hungry and cold like the wolf, Go wade like the crane: "+
                   "The palms of your hands will thicken, The skin of your cheek will tan, You'll grow ragged and weary and swarthy, "+
                   "But you'll walk like a man!");

           // 压入第一个BodyPart到MimeMultipart对象中。
           multi.addBodyPart(textBodyPart);

           // 创建第二个BodyPart,是一个FileDataSource
           FileDataSource fds = new FileDataSource("e:\注册码.txt");

           BodyPart fileBodyPart = new MimeBodyPart();    //第二个BodyPart
           fileBodyPart.setDataHandler(new DataHandler(fds));   //字符流形式装入文件
           fileBodyPart.setFileName(fds.getName());          //设置文件名，可以不是原来的文件名。 

           multi.addBodyPart(fileBodyPart);

           // MimeMultPart作为Content加入message
           message.setContent(multi);

           // 所有以上的工作必须保存。
           message.saveChanges(); 

           Transport.send(message);
           System.out.println("Mail send succesfully!");

       } catch (Exception e) ...{
           e.printStackTrace();
       }
   }
} 

用JavaMail接收邮件

package com.mailsystem.example;

import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.FetchProfile;
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.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.Provider;

public class MailReciever ...{
    public static final String mailServer = "127.0.0.1";
    public static final String mailUserName = "tang";
    public static final String mailPassword = "tang";
    public static final String mailProvider = "imap";

    //解析邮件内容
    private static void extractPart(final Part part) throws MessagingException, IOException ...{
        if(part.getContent() instanceof Multipart) ...{
            Multipart mp=(Multipart)part.getContent();
            for(int i=0;i<mp.getCount();i++) ...{
                extractPart(mp.getBodyPart(i));
            }
            return;
        }
        String fileName = part.getFileName();

        if(fileName == null) ...{
              System.out.println(part.getContent());
        } else if(fileName != null && !part.getContentType().startsWith("text/plain")) ...{
            //解析附件内容

            InputStream in=part.getInputStream();
            //保存附件，这里假设了一个文件，实际应该根据保存文件的类型来决定
            FileOutputStream out = new FileOutputStream("e:\att.txt");

            byte[] buffer=new byte[1024];
            int count=0;
            while((count=in.read(buffer))>=0) 
                out.write(buffer,0,count);
            in.close();
        }
    }

    public static void main(String []args) ...{
        Properties props = new Properties();

        props.setProperty("mail.pop3s.rsetbeforequit","true");
        props.setProperty("mail.pop3.rsetbeforequit","true");
        Session session=Session.getInstance(props,null);
        try ...{
            System.out.println("Getting store...");
            Store store = session.getStore(mailProvider);

            store.connect(mailServer, mailUserName, mailPassword);

            Folder folder = store.getFolder("inbox");

            folder.open(Folder.READ_WRITE);

            System.out.println("You have " + folder.getMessageCount() + " messages in inbox");
            System.out.println("You hava " + folder.getUnreadMessageCount() + " unread messages in inbox");
            Message []msgs = folder.getMessages();

            for (int i=0; i < msgs.length; i++) ...{

               MailReciever.extractPart(msgs[i]);

            }
            folder.close(false); //false：不删除标记为DELETED的邮件
            store.close();
        } catch (Exception ex) ...{
            ex.printStackTrace();
        }

    }

}