import com.nimbusds.jose.*;
import com.nimbusds.jose.crypto.RSADecrypter;
import com.nimbusds.jose.crypto.RSAEncrypter;

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;

public class JWSTest {
    public static void main(String[] args) {
        try {
            KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
            keyGen.initialize(1024);
            KeyPair key = keyGen.generateKeyPair();

            RSAPrivateKey privateKey = (RSAPrivateKey) key.getPrivate();
            RSAPublicKey publicKey = (RSAPublicKey) key.getPublic();

            JWEHeader header = new JWEHeader(JWEAlgorithm.RSA_OAEP_256, EncryptionMethod.A128GCM);

            Payload payload = new Payload("Hello world!");

            JWEObject jweObject = new JWEObject(header, payload);
            jweObject.encrypt(new RSAEncrypter(publicKey));

            String jweString = jweObject.serialize();

            System.out.println(jweString);

            jweObject = JWEObject.parse(jweString);

            jweObject.decrypt(new RSADecrypter(privateKey));

            payload = jweObject.getPayload();

            System.out.println(payload);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}