将字符串通过AES-128-CBC进行加密或者解密
key为需要加密或解密的字符串，sKey为主密钥，iv为偏移量。

//获取明文key
public static String getKey(String key, String sKey, String iv) {
    String DeString = null;
    try {
        key = key.substring(0, key.length() - 8);
        DeString = AESUtil.getInstance().decrypt(key, "utf-8", sKey, iv);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return DeString;
}

• AESUtil

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class AESUtil {
    /**
     * AES 是一种可逆加密算法，对用户的敏感信息加密处理
     * 对原始数据进行AES加密后，在进行Base64编码转化；
     */

    /*
     * 加密用的Key 可以用26个字母和数字组成
     * 此处使用AES-128-CBC加密模式，key需要为16位。
     */
    private static String sKey = "主密钥";
    private static String ivParameter = "偏移量";
    private static AESUtil instance = null;

    private AESUtil() {

    }

    public static AESUtil getInstance() {
        if (instance == null)
            instance = new AESUtil();
        return instance;
    }

    // 加密
    public String encrypt(String sSrc, String encodingFormat, String sKey, String ivParameter) throws Exception {
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        byte[] raw = sKey.getBytes();
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        IvParameterSpec iv = new IvParameterSpec(ivParameter.getBytes());//使用CBC模式，需要一个向量iv，可增加加密算法的强度
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
        byte[] encrypted = cipher.doFinal(sSrc.getBytes(encodingFormat));
        return new BASE64Encoder().encode(encrypted);//此处使用BASE64做转码。
    }

    // 解密
    public static String decrypt(String sSrc, String encodingFormat, String sKey, String ivParameter) throws Exception {
        try {
            byte[] raw = sKey.getBytes("ASCII");
            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            IvParameterSpec iv = new IvParameterSpec(ivParameter.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
            byte[] encrypted1 = new BASE64Decoder().decodeBuffer(sSrc);//先用base64解密
            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original, encodingFormat);
            return originalString;
        } catch (Exception ex) {
            return null;
        }
    }

    public static void main(String[] args) throws Exception {
        // 需要加密的字串
        String cSrc = "需要加密的字串";
        System.out.println(cSrc);
        // 加密
        long lStart = System.currentTimeMillis();
        String enString = AESUtil.getInstance().encrypt(cSrc,"utf-8",sKey,ivParameter);
        System.out.println("加密后的字串是："+ enString);

        long lUseTime = System.currentTimeMillis() - lStart;
        System.out.println("加密耗时：" + lUseTime + "毫秒");
        // 解密
        lStart = System.currentTimeMillis();
        String DeString = AESUtil.getInstance().decrypt(cSrc,"utf-8",sKey,ivParameter);
        System.out.println("解密后的字串是：" + DeString);
        lUseTime = System.currentTimeMillis() - lStart;
        System.out.println("解密耗时：" + lUseTime + "毫秒");
    }
}