[Java] [AES] How to generate key for AES encryption and decryption?

Problem
I would like to utilize AES to do text encryption and decryption, how to generate key?

How-To
Here has sample code to generate key:

package test.albert.security;

import java.security.NoSuchAlgorithmException;

import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class AESKeyGenerator {

    public static void main(String[] args) throws NoSuchAlgorithmException {
        AESKeyGenerator keyGen = new AESKeyGenerator();
        log.info(keyGen.generateKey());
    }

    public String generateKey() throws NoSuchAlgorithmException {
        String key = "";
        try {
            KeyGenerator keyGen = KeyGenerator.getInstance("AES");
            keyGen.init(128);
            SecretKey secretKey = keyGen.generateKey();
            key = toHex(secretKey.getEncoded());
        } catch (NoSuchAlgorithmException e) {
            throw e;
        }
        return key;
    }

    private String toHex(final byte[] data) {
        final StringBuilder sb = new StringBuilder(data.length * 2);
        for (final byte b : data) {
            sb.append(String.format("%02X", b));
        }
        return sb.toString();
    }
}

Here has sample code to do encrypt and decrypt:

package test.albert.security;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class AESUtils {

    private final static String SECURED_KEY = "A8167A5A6CF9783099B9FF34588C52B9";

    public static String encrypt(String inputText) throws NoSuchAlgorithmException, NoSuchPaddingException,
            InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        SecretKeySpec secretKey = new SecretKeySpec(SECURED_KEY.getBytes(), "AES");
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        String encryptedString = Base64.encodeBase64String(cipher.doFinal(inputText.getBytes()));
        return encryptedString;
    }

    public static String decrypt(String encryptedText) throws NoSuchAlgorithmException, NoSuchPaddingException,
            InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
        SecretKeySpec secretKey = new SecretKeySpec(SECURED_KEY.getBytes(), "AES");
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        String decryptedString = new String(cipher.doFinal(Base64.decodeBase64(encryptedText.getBytes())));
        return decryptedString;
    }

    public static void main(String[] args) throws Exception {
        String plainText = "test123abc";
        String encryptedText = AESUtils.encrypt(plainText);
        String decryptedText = AESUtils.decrypt(encryptedText);
        log.info(encryptedText);
        log.info(decryptedText);
    }
}

Remember to add commons-codec to your dependency in pom.xml

        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.11</version>
        </dependency>