JWT_HelloWorld.java

package com.gyoung.auto.jwt.demo;

import java.io.IOException;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.util.Date;

import org.bouncycastle.util.encoders.Base64;

import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.SignatureGenerationException;

public class JTWSigner {

	@SuppressWarnings("deprecation")
	public static void main(String[] args) throws NoSuchAlgorithmException, SignatureGenerationException, IOException {

		Date date = new Date();
		Date expiryDate = new Date();
		expiryDate.setDate(date.getDate() + 100);

		KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
		keyGen.initialize(2048);

		RSAPublicKey publicKey = (RSAPublicKey) keyGen.genKeyPair().getPublic();
		RSAPrivateKey privateKey = (RSAPrivateKey) keyGen.genKeyPair().getPrivate();

		String privKey = Base64.toBase64String(privateKey.getEncoded());
		String pubKey = Base64.toBase64String(publicKey.getEncoded());

		Algorithm algorithm = Algorithm.RSA256(publicKey, privateKey);

		String[] permsissions = { "do", "stuff", "with", "otherstuff" };

		String token = JWT.create()
				.withIssuedAt(date)
				.withNotBefore(date)
				.withExpiresAt(expiryDate)
				.withIssuer("Gordon Young")
				.withSubject("Gordon Young")
				.withArrayClaim("permissions", permsissions)
				.withAudience("All the peeps in the word")
				.withClaim("ClaimName", "ClaimValue")
				.sign(algorithm);

		System.out.println("Private key");
		System.out.println(privKey + "\n\n");
		System.out.println("Public key");
		System.out.println(pubKey + "\n\n");
		System.out.println("token");
		System.out.println(token);

	}

}