[JAVA100例]048、使用JavaMail接收邮件

原文：http://www.jspcn.net/htmlnews/11454144142501872.html
import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;
import java.io.*;
/**
 * <p>Title: 使用JavaMail接收邮件</p>
 * <p>Description: 实例JavaMail包接收邮件，本实例没有实现接收邮件的附件。</p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Filename: POPMail.java</p>
 * @version 1.0
 */
public class POPMail{
/**
 *<br>方法说明：主方法，接收用户输入的邮箱服务器、用户名和密码
 *<br>输入参数：
 *<br>返回类型：
 */
    public static void main(String args[]){
        try{
            String popServer=args[0];
            String popUser=args[1];
            String popPassword=args[2];
            receive(popServer, popUser, popPassword);
        }catch (Exception ex){
            System.out.println("Usage: java com.lotontech.mail.POPMail"+" popServer popUser popPassword");
        }
        System.exit(0);
    }
/**
 *<br>方法说明：接收邮件信息
 *<br>输入参数：
 *<br>返回类型：
 */
    public static void receive(String popServer, String popUser, String popPassword){
        Store store=null;
        Folder folder=null;
        try{
            //获取默认会话
            Properties props = System.getProperties();
            Session session = Session.getDefaultInstance(props, null);
            //使用POP3会话机制，连接服务器
            store = session.getStore("pop3");
            store.connect(popServer, popUser, popPassword);
            //获取默认文件夹
            folder = store.getDefaultFolder();
            if (folder == null) throw new Exception("No default folder");
            //如果是收件箱
            folder = folder.getFolder("INBOX");
            if (folder == null) throw new Exception("No POP3 INBOX");
            //使用只读方式打开收件箱
            folder.open(Folder.READ_ONLY);
            //得到文件夹信息，获取邮件列表
            Message[] msgs = folder.getMessages();
            for (int msgNum = 0; msgNum < msgs.length; msgNum++){
                printMessage(msgs[msgNum]);
            }
        }catch (Exception ex){
            ex.printStackTrace();
        }
        finally{
        //释放资源
            try{
                if (folder!=null) folder.close(false);
                if (store!=null) store.close();
            }catch (Exception ex2) {
                ex2.printStackTrace();
            }
        }
    }
/**
 *<br>方法说明：打印邮件信息
 *<br>输入参数：Message message 信息对象
 *<br>返回类型：
 */
    public static void printMessage(Message message){
        try{
            //获得发送邮件地址
            String from=((InternetAddress)message.getFrom()[0]).getPersonal();
            if (from==null) from=((InternetAddress)message.getFrom()[0]).getAddress();
            System.out.println("FROM: "+from);
            //获取主题
            String subject=message.getSubject();
            System.out.println("SUBJECT: "+subject);
            //获取信息对象
            Part messagePart=message;
            Object content=messagePart.getContent();
            //附件
            if (content instanceof Multipart){
                messagePart=((Multipart)content).getBodyPart(0);
                System.out.println("[ Multipart Message ]");
            }
            //获取content类型
            String contentType=messagePart.getContentType();
            //如果邮件内容是纯文本或者是HTML，那么打印出信息
            System.out.println("CONTENT:"+contentType);
            if (contentType.startsWith("text/plain")||
                contentType.startsWith("text/html")){
                InputStream is = messagePart.getInputStream();
                BufferedReader reader=new BufferedReader(new InputStreamReader(is));
                String thisLine=reader.readLine();
                while (thisLine!=null){
                    System.out.println(thisLine);
                    thisLine=reader.readLine();
                }
            }
            System.out.println("-------------- END ---------------");
        }catch (Exception ex){
            ex.printStackTrace();
        }
    }
}