package com.yuming.util;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.mail.Address;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.Message.RecipientType;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.internet.MimeUtility;

import sun.misc.BASE64Encoder;

public class Base64Util {
	
	/**
	 * @param args add by zxx ,Dec 30, 2008
	 * @throws IOException 
	 */
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		BASE64Encoder encoder = new BASE64Encoder();
		System.out.println("please input user name:");
		String username = new BufferedReader(
					new InputStreamReader(System.in))
					.readLine();
		System.out.println(encoder.encode(username.getBytes()));
		System.out.println("please input password:");
		String password = new BufferedReader(
				new InputStreamReader(System.in))
				.readLine();		
		System.out.println(encoder.encode(password.getBytes()));
	}
	

}

 BASE64Encoder encoder = new BASE64Encoder();这行导包报错

BASE64Encoder 应导入的包是   import sun.misc.BASE64Encoder;

解决方法:
Windows -> Preferences -> Java -> Compiler -> Errors/Warnings -> 
Deprecated and trstricted API -> Forbidden reference (access rules): ->改为 warning

即可.