AESHelper.java

package com.zenglb.baselib.utils;

import android.util.Log;

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


public class AESHelper{
    private static final String TAG = AESHelper.class.getSimpleName();
    private static final String ALGORITHM = "AES";
    private static final String TRANSFORMATION = "AES/ECB/PKCS5Padding";

    /**
     * 加密
     *
     * @param  input 加密的字符串
     * @param  key   解密的key
     * @return HexString
     */

    public static String encrypt(String input, String key){
        byte[] crypted = null;
        try{
            SecretKeySpec skey = new SecretKeySpec(key.getBytes(), ALGORITHM);
            Cipher cipher = Cipher.getInstance(TRANSFORMATION);
            cipher.init(Cipher.ENCRYPT_MODE, skey);
            crypted = cipher.doFinal(input.getBytes());
        }catch(Exception e){
            System.out.println(e.toString());
        }

        return parseByte2HexStr(crypted);
    }

    /**
     * 将二进制转换成16进制
     * @param buf
     * @return
     */
    private static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();

    }

    /**
     * 将16进制转换为二进制
     * @param hexStr
     * @return
     */
    private static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length()/2];
        for (int i = 0;i< hexStr.length()/2; i++) {
            int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);
            int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }

    /**
     * 解密
     *
     * @param  input 解密的字符串
     * @param  key   解密的key
     * @return String
     */
    public static String decrypt(String input, String key) {
        byte[] output = null;
        try {
            SecretKeySpec skey = new SecretKeySpec(key.getBytes(), ALGORITHM);
            Cipher cipher = Cipher.getInstance(TRANSFORMATION);
            cipher.init(Cipher.DECRYPT_MODE, skey);
            output = cipher.doFinal(parseHexStr2Byte(input));

        } catch (Exception e) {
            Log.e(TAG, "解密异常：" + e.toString());
        }
        return new String(output);
    }
}