第三个类：MyAuthenticator.java

package com.util.mail;  
 
import javax.mail.*;  
    
public class MyAuthenticator extends Authenticator{  
String userName=null;  
    String password=null;  
       
    public MyAuthenticator(){  
    }  
    public MyAuthenticator(String username, String password) {   
        this.userName = username;   
        this.password = password;   
    }   
    protected PasswordAuthentication getPasswordAuthentication(){  
        return new PasswordAuthentication(userName, password);  
    }  
}