[Sampling] 2. Resend Email Verification Sampling

GitHub - parangdajavous/resend-email-verification-sampling: resend 이메일 인증 샘플링

resend 이메일 인증 샘플링. Contribute to parangdajavous/resend-email-verification-sampling development by creating an account on GitHub.

https://github.com/parangdajavous/resend-email-verification-sampling.git

1. Resend 회원가입

Resend · Email for developers

The best way to reach humans instead of spam folders. Deliver transactional and marketing emails at scale.

https://resend.com/

2. API 키 발급 + 복사

3. 프로젝트 생성

의존성 추가

implementation 'com.squareup.okhttp3:okhttp:4.12.0'
implementation 'com.fasterxml.jackson.core:jackson-databind:2.17.0'

CodeUtil

package com.metacoding;

import java.security.SecureRandom;

public class CodeUtil {
    private static final SecureRandom random = new SecureRandom();
    private static final int CODE_LENGTH = 6;

    /**
     * 6자리 숫자 인증번호 생성 (ex. "583241")
     */
    public static String generateAuthCode() {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < CODE_LENGTH; i++) {
            sb.append(random.nextInt(10)); // 0~9
        }
        return sb.toString();
    }
}

EmailService

package com.metacoding;

import com.fasterxml.jackson.databind.ObjectMapper;
import okhttp3.*;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class EmailService {
    private final String API_KEY = System.getenv("RESEND_API_KEY"); // ← Resend API Key
    private final OkHttpClient client = new OkHttpClient();
    private final ObjectMapper objectMapper = new ObjectMapper();

    public void sendVerificationEmail(String toEmail, String authCode) throws IOException {
        String url = "https://api.resend.com/emails";

        // ✅ 이메일 내용 구성
        Map<String, Object> payload = new HashMap<>();
        payload.put("from", "인증센터 <onboarding@resend.dev>");
        payload.put("to", toEmail);
        payload.put("subject", "이메일 인증번호 안내"); // ← subject 추가 필수
        payload.put("html", "<p>당신의 인증번호는 <strong>" + authCode + "</strong> 입니다.</p>");

        // ✅ JSON 변환
        String json = objectMapper.writeValueAsString(payload);
        RequestBody body = RequestBody.create(json, MediaType.get("application/json"));

        // ✅ 요청 생성
        Request request = new Request.Builder()
                .url(url)
                .header("Authorization", "Bearer " + API_KEY)
                .post(body)
                .build();

        // ✅ 요청 실행 및 응답 처리
        try (Response response = client.newCall(request).execute()) {
            System.out.println("응답 코드: " + response.code());

            if (!response.isSuccessful()) {
                String errorBody = response.body() != null ? response.body().string() : "No response body";
                throw new IOException("이메일 전송 실패: " + errorBody);
            }

            System.out.println("✅ 이메일 전송 성공!");
        }
    }
}

Main

package com.metacoding;

//TIP To <b>Run</b> code, press <shortcut actionId="Run"/> or
// click the <icon src="AllIcons.Actions.Execute"/> icon in the gutter.
public class Main {
    public static void main(String[] args) throws Exception {

        try {
            String email = "nuit0535@gmail.com";

            // 🔹 인증번호 생성
            String authCode = CodeUtil.generateAuthCode();
            System.out.println("생성된 인증번호: " + authCode);

            // 🔹 이메일 전송
            EmailService service = new EmailService();
            service.sendVerificationEmail(email, authCode);
        } catch (Exception e) {
            e.printStackTrace();  // 어떤 예외가 나는지 확인
        }
    }
}