java实现AES加解密

AES工具类

import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Base64;
import java.util.logging.Level;
import java.util.logging.Logger;

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

public class AESUtil {

	private static final String KEY_ALGORITHM = "AES";
	private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";// 默认的加密算法
	private static final String KEY = "good!good@study#day$day%up";

	/**
	 * AES 加密操作
	 *
	 * @param content
	 *            待加密内容
	 * @param key
	 *            加密密钥
	 * @return 返回Base64转码后的加密数据
	 */
	public static String encrypt(String content) {
		try {
			Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);// 创建密码器
			byte[] byteContent = content.getBytes("utf-8");
			cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(KEY));// 初始化为加密模式的密码器
			byte[] result = cipher.doFinal(byteContent);// 加密
			return Base64.getEncoder().encodeToString(result);// 通过Base64转码返回
		} catch (Exception ex) {
			Logger.getLogger(AESUtil.class.getName()).log(Level.SEVERE, null, ex);
		}
		return null;
	}

	/**
	 * AES 解密操作
	 *
	 * @param content
	 * @param key
	 * @return
	 */
	public static String decrypt(String content) {
		try {
			// 实例化
			Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
			// 使用密钥初始化，设置为解密模式
			cipher.init(Cipher.DECRYPT_MODE, getSecretKey(KEY));
			// 执行操作
			byte[] result = cipher.doFinal(Base64.getDecoder().decode(content));
			return new String(result, "utf-8");
		} catch (Exception ex) {
			Logger.getLogger(AESUtil.class.getName()).log(Level.SEVERE, null, ex);
		}

		return null;
	}

	/**
	 * 生成加密秘钥
	 *
	 * @return
	 * @throws NoSuchAlgorithmException
	 */
	private static SecretKeySpec getSecretKey(final String key) throws NoSuchAlgorithmException {
		// 返回生成指定算法密钥生成器的 KeyGenerator 对象
		KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM);
		// AES 要求密钥长度为 128
		kg.init(128, new SecureRandom(key.getBytes()));
		// 生成一个密钥
		SecretKey secretKey = kg.generateKey();
		return new SecretKeySpec(secretKey.getEncoded(), KEY_ALGORITHM);// 转换为AES专用密钥
	}

}

字节工具类

public class BytesUtil {
	
	/**
	 * 16进制表示字符
	 */
	public static final String hexStr = "0123456789abcdef";
	
	/**
	 * 16进制的数字
	 */
	public static final char[] chars = hexStr.toCharArray(); 
	
	/**
	 * 字节转字符串
	 */
	public static String byte2HexString(byte[] buff) {
		if( buff == null ) {
			return null;
		}
		int len = buff.length;
		int j=0;
		char[] chs = new char[len * 2];
		for ( int i=0 ; i<len ; i++) {
			chs[j++] =  chars[ buff[i] >> 4 & 0x0f ];
			chs[j++] = chars[ buff[i] & 0x0f];
		}
		return new String(chs);
	}
	
	/**
	 * 16进制字符串转字节
	 */
	public static byte[] hexString2Bytes(String hexString) {
		if( hexString == null || hexString.length() == 0) {
			return null;
		}
		char[] arrs = hexString.toCharArray();
		int len = arrs.length / 2 ;
		byte[] buff = new byte[len];
		int j=0;
		for(int i=0;i<arrs.length;i+=2) {
			byte high = (byte) hexStr.indexOf(arrs[i]);
			byte low = (byte) hexStr.indexOf(arrs[i+1]);
			buff[j++] = (byte) (high << 4 & 0xf0 | low) ;
		}
		return buff;
	}
	
}