AES加密解密 Java中运用

AES全称 Advanced Encryption Standard， 高级加密算法，更加安全，可取代DES。

Aes：

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;
    }
}

MainAes：

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);
    }

}