BouncyCastle AES 256 CBC Java <-> Js

Main.java

/*
 * Unrestricted security policy files for Java JRE need to be installed from Oracle for 256 keys to work
 */
package com.mycompany.mavenproject1;

import java.security.SecureRandom;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import java.util.Base64;
import java.util.Arrays;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

public class Main {

    private static final int keyLength = 32;
    private static final SecureRandom random = new SecureRandom();
    
    private static SecretKey key;
    private static byte[] iv;

    public static void main(String [] args) throws Exception {
        Security.addProvider(new BouncyCastleProvider());
        
        String plaintext = "hello world";
        byte [] ciphertext = encrypt(plaintext);
        String recoveredPlaintext = decrypt(ciphertext);

        System.out.println(recoveredPlaintext);
    }
    
    private static void printByteArr(byte[] arr) {
        System.out.print("[");
        for (int i = 0; i < arr.length; i++) {
            System.out.printf(i == 0 ? "%d" : ",%d", (arr[i] & 0xFF));
        }
        System.out.println("]");
    }

    private static byte [] encrypt(String plaintext) throws Exception {
        key = generateKey();

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
        String ivStr = "0123456789abcdef";
        iv = ivStr.getBytes("US-ASCII");
        cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
        
        System.out.println(
                Base64.getEncoder().withoutPadding()
                    .encodeToString(key.getEncoded())
        );
        printByteArr(iv);
        return cipher.doFinal(plaintext.getBytes());
    }

    private static String decrypt(byte [] ciphertext) throws Exception {
        printByteArr(ciphertext);
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
        cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
        return new String(cipher.doFinal(ciphertext));
    }

    private static SecretKey generateKey() throws Exception {
        byte[] keyBytes = new byte[keyLength];
        random.nextBytes(keyBytes);
        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
        return keySpec;
    }

    private static IvParameterSpec generateIV(Cipher cipher) throws Exception {
        byte [] ivBytes = new byte[cipher.getBlockSize()];
        random.nextBytes(ivBytes);
        return new IvParameterSpec(ivBytes);
    }
}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mycompany</groupId>
    <artifactId>mavenproject1</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.bouncycastle/bcprov-jdk15on -->
        <dependency>
            <groupId>org.bouncycastle</groupId>
            <artifactId>bcprov-jdk15on</artifactId>
            <version>1.58</version>
        </dependency>
    </dependencies>
</project>

test.js

var key; 
crypto.subtle.importKey(
                        "jwk",
                        { kty: "oct", k: "3xWUgMp33fKgl8xTYgn7Ono5yE9H4I879znj2fUxBYU", alg: "A256CBC", ext: true },
                        { name: "AES-CBC" },
                        true,
                        ["encrypt", "decrypt"]
    )
    .then(function(importedKey) {
        key = importedKey;
    })
    .catch(function(err) {
        console.error(err);
    });
var iv = Uint8Array.from([48,49,50,51,52,53,54,55,56,57,97,98,99,100,101,102])
var data = Uint8Array.from([225,175,9,149,146,159,199,27,171,164,230,135,152,103,23,189])
var decrypted;
crypto.subtle.decrypt(
                      { name: "AES-CBC", iv: iv },
                      key,
                      data
    )
    .then(function(decr) {
        decrypted = new Uint8Array(decr);
        decrypted.map( function(b) { console.log(String.fromCharCode(b)) } )
    })
    .catch(function(err) {
        console.error(err, data);
    });

Hi! Is there anyway I can reach you about this code? I'd like to implement this in Go but I have some questions about where you got some values. Thank you!