package com.blog.d201706.encrypt;

import javax.crypto.Cipher;

import javax.crypto.spec.SecretKeySpec;

import java.security.Key;

public class Aes {

    /**

     * 加解密key

     */

    private final Key keySpec;

    /**

     * 构造函数

     * @param key

     */

    public Aes(String key){

        keySpec = new SecretKeySpec(key.getBytes(), "AES");

    }

    /**

     * 加密

     * @param str

     * @return

     */

    public String encryt(String str) {

        // 根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式

        try {

            Cipher c = Cipher.getInstance("AES");

            c.init(Cipher.ENCRYPT_MODE, keySpec);

            byte[] src = str.getBytes();

            // 加密，结果保存进cipherByte

            byte[] cipherByte = c.doFinal(src);

            return parseByte2HexStr(cipherByte);

        } catch (Exception e) {

            e.printStackTrace();

        }

        return null;

    }

    /**

     * 解密

     * @param deCodeStr

     * @return

     */

    public String decrypt(String deCodeStr) {

        // 根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式

        try {

            if (null == deCodeStr) return null;

            byte[] buff = parseHexStr2Byte(deCodeStr);

            Cipher c;

            c = Cipher.getInstance("AES");

            c.init(Cipher.DECRYPT_MODE, keySpec);

            byte[] cipherByte = c.doFinal(buff);

            return new String(cipherByte);

        } catch (Exception e) {

            e.printStackTrace();

        }

        return null;

    }

    /**

     * 将二进制转换成16进制

     *

     * @param buf

     * @return

     */

    public 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

     */

    public 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;

    }

}

package com.blog.d201706.encrypt;

public class MainAes {

    public static void main(String[] args) throws Exception {

        Aes aes = new Aes("1234567890123456");

        String msg = "测试文本：今天周5" + System.currentTimeMillis();

        String encontent = aes.encryt(msg);

        String decontent = aes.decrypt(encontent);

        System.out.println("明文是:" + msg);

        System.out.println("加密后:" + encontent);

        System.out.println("解密后:" + decontent);

    }

}