Servlet 이메일인증 라이브러리

• 서블릿에서 이메일 인증 하는 법
  필수로 필요한 라이브러리 (jar) 파일
  -> mailapi.jar
  -> activation.jar
  -> smtp.jar

밑 3개는 꼭 필요한 것은 아니다
-> pop3.jar
-> imap.jar
-> mime.jar

차이점은 밑 사이트에서 비교!
https://sirius2k.tistory.com/49

package kakaoprotect;

import java.io.IOException;
import java.util.Properties;
import java.util.Random;

import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


@WebServlet("/SendCertification")
public class SendCertification extends HttpServlet {
	private static final long serialVersionUID = 1L;

    public SendCertification() {
        super();
        // TODO Auto-generated constructor stub
    }


	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println("dd");

		//mail server 설정

		String smtpEmail = "bogdudhkd123@gmail.com"; 
		String password = "uregzrrzxkpfkcld";

		//메일 받을 주소
		String to_email = "bogdudhkd123@gmail.com";

		//SMTP 서버 정보를 설정한다.

		
	
		/* Properties p = new Properties(); */
	       Properties p = System.getProperties();
			p.setProperty("mail.transport.protocol", "smtp");
			/* p.setProperty("mail.host", "smtp.gmail.com"); */
	       p.put("mail.smtp.host", "smtp.gmail.com");
	       p.put("mail.smtp.port", "587");
	       p.put("mail.smtp.auth", "true");
		   p.put("mail.smtp.debug", "true");
	       p.put("mail.smtp.starttls.enable", "true");
	       p.put("mail.smtp.ssl.protocols", "TLSv1.2");
	       p.put("mail.smtp.socketFactory.port", "587");
	       p.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
	       
	      
		//인증 번호 생성기
		StringBuffer temp =new StringBuffer();
		Random rnd = new Random();
		for(int i=0;i<10;i++)
		{
			int rIndex = rnd.nextInt(3);
			switch (rIndex) {
			case 0:
				// a-z
				temp.append((char) ((int) (rnd.nextInt(26)) + 97));
				break;
			case 1:
				// A-Z
				temp.append((char) ((int) (rnd.nextInt(26)) + 65));
				break;
			case 2:
				// 0-9
				temp.append((rnd.nextInt(10)));
				break;
			}
		}
		String AuthenticationKey = temp.toString();
		System.out.println(AuthenticationKey);

		Session session = Session.getDefaultInstance(p, new javax.mail.Authenticator() {
			protected PasswordAuthentication getPasswordAuthentication() {
				return new PasswordAuthentication(smtpEmail,password);
			}
		});

		//email 전송
		try {
			
			MimeMessage msg = new MimeMessage(session);
	
			msg.addRecipient(Message.RecipientType.TO, new InternetAddress(to_email));
			
			System.out.println(msg);
			//메일 제목
			msg.setSubject("제목");
			//메일 내용
			msg.setText("인증 번호는 ["+temp +"] 입니다");
			
			Transport t = session.getTransport("smtp");
			t.connect(smtpEmail,password);
			t.sendMessage(msg, msg.getAllRecipients());
			t.close();
			
			
			
			System.out.println("이메일 전송");

		}catch (Exception e) {
			e.printStackTrace();// TODO: handle exception
		}

	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}