java AES 加密解密工具（Advanced Encryption Standard）发现明文相同但每次重启服务后密文就会不同于是有了改进

1、通用方法  

package com.qlkj.hzd.commom.utils;

import javax.crypto.*;
import java.io.UnsupportedEncodingException;
import java.security.*;

/**
 * RSA相关工具类
 *
 * @author vampire
 * @date 2018/10/12 下午5:33
 */
public class EncrypAES {

    //KeyGenerator                提供对称密钥生成器的功能，支持各种算法
    private static KeyGenerator keygen;
    //SecretKey                负责保存对称密钥
    private static SecretKey deskey;
    //Cipher负责完成加密或解密工作
    private static Cipher c;
    //该字节数组负责保存加密的结果
    private static byte[] cipherByte;

    static {
        try {
            Security.addProvider(new com.sun.crypto.provider.SunJCE());
            //实例化支持DES算法的密钥生成器(算法名称命名需按规定，否则抛出异常)
            keygen = KeyGenerator.getInstance("AES");
            //生成密钥
            deskey = keygen.generateKey();
            //生成Cipher对象,指定其支持的DES算法
            c = Cipher.getInstance("AES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        }

    }

    /**
     * 对字符串加密
     *
     * @param str
     * @return
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public static String Encrytor(String str) throws InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
        //                根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式
        c.init(Cipher.ENCRYPT_MODE, deskey);
        byte[] src = str.getBytes("utf-8");
        //                加密，结果保存进cipherByte
        cipherByte = c.doFinal(src);
        return parseByte2HexStr(cipherByte);
    }

    /**
     * 对字符串解密
     *
     * @param str
     * @return
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public static String Decryptor(String str) throws InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException {
        //                根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式
        c.init(Cipher.DECRYPT_MODE, deskey);
        cipherByte = c.doFinal(parseHexStr2Byte(str));
        return new String(cipherByte);
    }

    /**
     * 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;
    }


    /**
     * 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();
    }

}

2、添加密码加解密

public static byte[] decrypt(byte[] content, String password) {
        try {
                 KeyGenerator kgen = KeyGenerator.getInstance("AES");
                 kgen.init(128, new SecureRandom(password.getBytes()));
                 SecretKey secretKey = kgen.generateKey();
                 byte[] enCodeFormat = secretKey.getEncoded();
                 SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");           
                 Cipher cipher = Cipher.getInstance("AES");// 创建密码器
                cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
                byte[] result = cipher.doFinal(content);
                return result; // 加密
        } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
        } catch (NoSuchPaddingException e) {
                e.printStackTrace();
        } catch (InvalidKeyException e) {
                e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
                e.printStackTrace();
        } catch (BadPaddingException e) {
                e.printStackTrace();
        }
        return null;
}

 3、由于每次启动服务生产的

SecretKey secretKey = kgen.generateKey(); 会变 所以在 下边初始化时就将key写死。

package com.qlkj.hzd.commom.utils;

import com.alibaba.fastjson.JSONObject;

import javax.crypto.*;
import java.io.UnsupportedEncodingException;
import java.security.*;

/**
 * RSA相关工具类
 *
 * @author vampire
 * @date 2018/10/12 下午5:33
 */
public class EncrypAES {

    //KeyGenerator 提供对称密钥生成器的功能，支持各种算法
    private static KeyGenerator keygen;
    //SecretKey   负责保存对称密钥
    private static SecretKey deskey = new SecretKey() {
        @Override
        public String getAlgorithm() {
            return "AES";
        }

        @Override
        public String getFormat() {
            return "RAW";
        }

        @Override
        public byte[] getEncoded() {
            MessageDigest md = null;
            byte[] thedigest = null;
            try {
                md = MessageDigest.getInstance("MD5");
                thedigest = md.digest("pe1mUKtDZWxX2O41ea5+Tg==".getBytes("utf-8"));
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            return thedigest;
        }
    };
    //Cipher负责完成加密或解密工作
    private static Cipher c;
    //该字节数组负责保存加密的结果
    private static byte[] cipherByte;

    static {
        try {
            Security.addProvider(new com.sun.crypto.provider.SunJCE());
            //实例化支持DES算法的密钥生成器(算法名称命名需按规定，否则抛出异常)
            keygen = KeyGenerator.getInstance("AES");
            //生成密钥
            //  deskey = keygen.generateKey();
            System.out.println(JSONObject.toJSONString(deskey));
            //生成Cipher对象,指定其支持的DES算法
            c = Cipher.getInstance("AES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        }

    }

    /**
     * 对字符串加密
     *
     * @param str
     * @return
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public static String encrytor(String str) throws InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
        //  根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式
        c.init(Cipher.ENCRYPT_MODE, deskey);
        byte[] src = str.getBytes("utf-8");
        //                加密，结果保存进cipherByte
        cipherByte = c.doFinal(src);
        return parseByte2HexStr(cipherByte);
    }

    /**
     * 对字符串解密
     *
     * @param str
     * @return
     * @throws InvalidKeyException
     * @throws IllegalBlockSizeException
     * @throws BadPaddingException
     */
    public static String decryptor(String str) throws InvalidKeyException,
            IllegalBlockSizeException, BadPaddingException {
        //                根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式
        c.init(Cipher.DECRYPT_MODE, deskey);
        cipherByte = c.doFinal(parseHexStr2Byte(str));
        return new String(cipherByte);
    }

    /**
     * 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;
    }


    /**
     * 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();
    }

}