encrypt and decrypt with PBKDF2/SHA1 and AES

Decrypter.java

import javax.crypto.Cipher;
import java.security.spec.KeySpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import javax.crypto.SecretKeyFactory;
import java.security.AlgorithmParameters;
import javax.crypto.spec.IvParameterSpec;

public class Decrypter {
    Cipher dcipher;

    byte[] salt = new String("12345678").getBytes();
    int iterationCount = 1024;
    int keyStrength = 256;
    SecretKey key;
    byte[] iv;

    Decrypter(String passPhrase) throws Exception {
        SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
        KeySpec spec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount, keyStrength);
        SecretKey tmp = factory.generateSecret(spec);
        key = new SecretKeySpec(tmp.getEncoded(), "AES");
        dcipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    }

    public String encrypt(String data) throws Exception {
        dcipher.init(Cipher.ENCRYPT_MODE, key);
        AlgorithmParameters params = dcipher.getParameters();
        iv = params.getParameterSpec(IvParameterSpec.class).getIV();
        byte[] utf8EncryptedData = dcipher.doFinal(data.getBytes());
        String base64EncryptedData = new sun.misc.BASE64Encoder().encodeBuffer(utf8EncryptedData);

        System.out.println("IV " + new sun.misc.BASE64Encoder().encodeBuffer(iv));
        System.out.println("Encrypted Data " + base64EncryptedData);
        return base64EncryptedData;
    }

    public String decrypt(String base64EncryptedData) throws Exception {
        dcipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
        byte[] decryptedData = new sun.misc.BASE64Decoder().decodeBuffer(base64EncryptedData);
        byte[] utf8 = dcipher.doFinal(decryptedData);
        return new String(utf8, "UTF8");
    }

    public static void main(String args[]) throws Exception {
        Decrypter decrypter = new Decrypter("ABCDEFGHIJKL");
        String encrypted = decrypter.encrypt("the quick brown fox jumps over the lazy dog");
        String decrypted = decrypter.decrypt(encrypted);
        System.out.println(decrypted);
    }
}

I Have an Encrypted String, how can i decrypt it
String = "p1SvSCiAxupKrrZXzjXQk3lWe88xW7mTymvqGlmAOMM9DbYm3kkq7BLP336HwRdYOIBU9VNL0tFTchwBKbw+ZOlU6Ny3vTOtA3/hPqSUOOXDEu5aKnbbvywefu3jyX1u/EFbc1uqohJspem+d1kwxmzn
tbvui8AH6+mckIb6I9c="

In a scenario where decrypt is called first (no call to encrypt) , iv is null and there is a null pointer exception. I encountered this after reading encrypted data from Firebase and trying to decrypt.

@Yair0007 I faced this too. Did you manage to find the solution ?