/*** Created by LvJianwei on 2018/2/8.*/import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;/*** @program: reflection* @description: AES* @author: LvJianwei* @create: 2018-02-08 15:07**/
public class AESDemo {public static void main(String[] args) {String key="i will always love you";byte[] keyBytes=initSecretKey();String plainText="have a nice day";System.out.println("plainText:"+plainText);byte[] encryptedBytes=encrypt(DEFAULT_CIPHER_ALGORITHM,keyBytes,KEY_ALGORITHM,plainText);System.out.println("encryptedText:"+Arrays.toString(encryptedBytes));byte[] decryptedBytes=decrypt(DEFAULT_CIPHER_ALGORITHM,keyBytes,KEY_ALGORITHM,encryptedBytes);System.out.println("decryptedText:"+new String(decryptedBytes));}/*** algorithm*/private static final String KEY_ALGORITHM = "AES";private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";/*** generate key* @return byte[] key* @throws Exception*/public static byte[] initSecretKey() {//返回生成指定算法的秘密密钥的 KeyGenerator 对象KeyGenerator kg = null;try {kg = KeyGenerator.getInstance(KEY_ALGORITHM);} catch (NoSuchAlgorithmException e) {e.printStackTrace();return new byte[0];}//初始化此密钥生成器，使其具有确定的密钥大小//AES 要求密钥长度为 128kg.init(128);//生成一个密钥SecretKey secretKey = kg.generateKey();return secretKey.getEncoded();}/*** AESEncrypt* @param cipherAlgorithm   transformation* @param keyBytes  key byte array* @param keyAlgorithm  SecretKeySpec's algorithm* @param plainText text to be encrypted* @return*/public static byte[] encrypt(String cipherAlgorithm, byte[] keyBytes, String keyAlgorithm, String plainText) {try {Cipher cipher = Cipher.getInstance(cipherAlgorithm);String keyStr= DatatypeConverter.printBase64Binary(keyBytes);SecretKeySpec keySpec = new SecretKeySpec(keyBytes, keyAlgorithm);cipher.init(Cipher.ENCRYPT_MODE, keySpec);byte[] encyptedBytes = cipher.doFinal(plainText.getBytes());return encyptedBytes;} catch (Exception e) {e.printStackTrace();}return null;}/*** decrypt* @param cipherAlgorithm transformation* @param keyBytes key* @param keyAlgorithm SecretKeySpec's algorithm* @param encyptedBytes encypted byte array* @return*/public static byte[] decrypt(String cipherAlgorithm, byte[] keyBytes, String keyAlgorithm, byte[] encyptedBytes) {try {Cipher cipher = Cipher.getInstance(cipherAlgorithm);String keyStr= DatatypeConverter.printBase64Binary(keyBytes);SecretKeySpec keySpec = new SecretKeySpec(keyBytes, keyAlgorithm);cipher.init(Cipher.DECRYPT_MODE, keySpec);byte[] decryptedBytes = cipher.doFinal(encyptedBytes);return decryptedBytes;} catch (Exception e) {e.printStackTrace();}return null;}
}