src/main/java/com/pt/utils/JWTUtils.java

package com.pt.utils;

import com.pt.constant.Constants;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

import java.nio.charset.StandardCharsets;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;

public class JWTUtils {

    private final static String SECRET_KEY = "U2VjcmV0S2V5Rm9ySldUVXNlT25seUluU2VjdXJlRW52aXJvbm1lbnQ=";


    public static String createToken(Map<String, Object> params, long ttlMills){

        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS256;
        long expMillis = System.currentTimeMillis() + ttlMills;
        Date exp = new Date(expMillis);
        return Jwts.builder()
                .setClaims(params)
                .signWith(signatureAlgorithm, SECRET_KEY.getBytes(StandardCharsets.UTF_8))
                .setExpiration(exp)
                .compact();

    }

    public static Map<String, Object> parseToken(String token){
        try{
            return Jwts.parser()
                    .setSigningKey(SECRET_KEY.getBytes(StandardCharsets.UTF_8))
                    .parseClaimsJws(token).getBody();
        }catch (Exception e){
            return null;
        }

    }

    public static boolean checkToken(String token, String username, Constants.UserRole userType) {
        Map<String, Object> claims = parseToken(token);
        if(claims == null) {
            System.out.println("Token is invalid or expired");
            return false;
        }
        String tokenUsername = (String) claims.get("username");
        int tokenUserType = (int) claims.get("userType");

        System.out.printf("Token username: %s, Token userType: %d, Provided username: %s, Provided userType: %d%n",
                tokenUsername, tokenUserType, username, userType.getValue());

        return tokenUsername.equals(username) && tokenUserType >= userType.getValue();
    }

    public static String generateToken(String username,
                                 Constants.UserRole userType,
                                 long expireTime) {
        Map<String, Object> claims = new HashMap<>();
        claims.put("username", username);
        claims.put("userType", userType.getValue());
        return createToken(claims, expireTime);
    }
}