AESUtil AES加密工具类

AES加密工具类，其中导入的jar包jdk引进去就可以用了，jdk的版本尽量大于1.5

package com.g.mavenspring.demo.util;
/**   
 * @Title: AESUtil.java 
 * @Package com.g.mavenspring.demo.util 
 * @Description: TODO(用一句话描述该文件做什么) 
 * @author 
 * @date 2015年12月29日 下午2:38:00 
 * @version V1.0   
 */
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

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

public class AESUtil {

	public static void main(String[] args) {
		// 密钥的种子，可以是任何形式，本质是字节数组
				String strKey = "aaaa";
				// 密钥数据
				byte[] rawKey = getRawKey(strKey.getBytes());
				// 密码的明文
				String clearPwd = "My world is full of wonders! No body can match my spirit";
				// 密码加密后的密文
				byte[] encryptedByteArr = encrypt(rawKey, clearPwd);
				String encryptedPwd = new String(encryptedByteArr);
				System.out.println(encryptedPwd);
				// 解密后的字符串
				String decryptedPwd = decrypt(encryptedByteArr, rawKey);
				System.out.println(decryptedPwd);

	}

	/**
	 * @param rawKey
	 *            密钥
	 * @param clearPwd
	 *            明文字符串
	 * @return 密文字节数组
	 */
	private static byte[] encrypt(byte[] rawKey, String clearPwd) {
		try {
			SecretKeySpec secretKeySpec = new SecretKeySpec(rawKey, "AES");
			Cipher cipher = Cipher.getInstance("AES");
			cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
			byte[] encypted = cipher.doFinal(clearPwd.getBytes());
			return encypted;
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * @param encrypted
	 *            密文字节数组
	 * @param rawKey
	 *            密钥
	 * @return 解密后的字符串
	 */
	private static String decrypt(byte[] encrypted, byte[] rawKey) {
		try {
			SecretKeySpec secretKeySpec = new SecretKeySpec(rawKey, "AES");
			Cipher cipher = Cipher.getInstance("AES");
			cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
			byte[] decrypted = cipher.doFinal(encrypted);
			return new String(decrypted);
		} catch (Exception e) {
			return "";
		}
	}

	/**
	 * @param seed种子数据
	 * @return 密钥数据
	 */
	private static byte[] getRawKey(byte[] seed) {
		byte[] rawKey = null;
		try {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
			secureRandom.setSeed(seed);
			// AES加密数据块分组长度必须为128比特，密钥长度可以是128比特、192比特、256比特中的任意一个
			kgen.init(128, secureRandom);
			SecretKey secretKey = kgen.generateKey();
			rawKey = secretKey.getEncoded();
		} catch (NoSuchAlgorithmException e) {
		}
		return rawKey;
	}
}