import java.nio.charset.StandardCharsets;

import java.time.LocalDateTime;

import java.time.ZoneOffset;

import java.util.UUID;

import java.util.Base64;

import javax.crypto.Mac;

import org.json.JSONObject;

import javax.crypto.spec.SecretKeySpec;

import org.joget.commons.util.LogUtil;

        try {            

int EXPIRY_DAYS = 1;  

JSONObject payload = new JSONObject();

String JWT_HEADER = "{\"alg\":\"HS256\",\"typ\":\"JWT\"}";

String encodedHeader = Base64.getUrlEncoder().withoutPadding().encodeToString(JWT_HEADER.getBytes());   

String SECRET_KEY =  "Sceret Key";

String apiKey = "Api Key";

JSONObject jwtPayload = new JSONObject();

jwtPayload.put("status", 0);jwtPayload.put("sub", "admin");

LocalDateTime ldt = LocalDateTime.now().plusDays(EXPIRY_DAYS);

jwtPayload.put("exp", ldt.toEpochSecond(ZoneOffset.UTC));

payload.put("sub", jwtPayload.getString("sub")); payload.put("exp", jwtPayload.getLong("exp"));             payload.put("iss", apiKey);payload.put("iat", LocalDateTime.now().toEpochSecond(ZoneOffset.UTC));             payload.put("jti", UUID.randomUUID().toString());

String secret = SECRET_KEY;

String data = encodedHeader + "." +Base64.getUrlEncoder().withoutPadding().encodeToString(payload.toString().getBytes());

byte[] hash = secret.getBytes(StandardCharsets.UTF_8);

Mac sha256Hmac = Mac.getInstance("HmacSHA256");

SecretKeySpec secretKey = new SecretKeySpec(hash, "HmacSHA256");

sha256Hmac.init(secretKey);

byte[] signedBytes = sha256Hmac.doFinal(data.getBytes(StandardCharsets.UTF_8));

String signature = Base64.getUrlEncoder().withoutPadding().encodeToString(signedBytes);            

String token = encodedHeader + "." +                     Base64.getUrlEncoder().withoutPadding().encodeToString(payload.toString().getBytes())+ "." + signature;             
LogUtil.info("token", token);        
//Code to call the external API
//=============================
}catch(Exception ex) {LogUtil.info("token catch", ex.toString());}