import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Base64;
import java.util.Scanner;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

/*

• AES对称加密和解密
  */
  public class SymmetricEncoder {

  public static byte[] generatorKey(String encodeRules) {
  byte[] keyByteArray = null;
  //1.构造密钥生成器，指定为AES算法,不区分大小写
  KeyGenerator keygen = null;
  try {
  keygen = KeyGenerator.getInstance(“AES”);
  //2.根据ecnodeRules规则初始化密钥生成器
  //生成一个128位的随机源,根据传入的字节数组
  /keygen.init(128, new SecureRandom(encodeRules.getBytes()));/
  SecureRandom random = null;
  random = SecureRandom.getInstance(“SHA1PRNG”);
  random.setSeed(encodeRules.getBytes());
  keygen.init(128, random);
  } catch (Exception e) {
  e.printStackTrace();
  }
  SecretKey original_key = keygen.generateKey();
  keyByteArray = original_key.getEncoded();
  //System.out.println(“keyByteArray==================” + keyByteArray.toString());
  return keyByteArray;
  }

  /*

  • 加密

  • 1.构造密钥生成器

  • 2.根据ecnodeRules规则初始化密钥生成器

  • 3.产生密钥

  • 4.创建和初始化密码器

  • 5.内容加密

  • 6.返回字符串
    */
    public static String AESEncode(String encodeRules, String content) {
    try {
    //1.获得原始对称密钥的字节数组
    byte[] raw = generatorKey(encodeRules);
    //2.根据字节数组生成AES密钥
    SecretKey key = new SecretKeySpec(raw, “AES”);
    //3.根据指定算法AES自成密码器
    Cipher cipher = Cipher.getInstance(“AES”);
    //4.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作，第二个参数为使用的KEY
    cipher.init(Cipher.ENCRYPT_MODE, key);
    //5.获取加密内容的字节数组(这里要设置为utf-8)不然内容中如果有中文和英文混合中文就会解密为乱码
    byte[] byte_encode = content.getBytes(“utf-8”);
    //6.根据密码器的初始化方式–加密：将数据加密
    byte[] byte_AES = cipher.doFinal(byte_encode);
    //7.将加密后的数据转换为字符串
    //这里用Base64Encoder中会找不到包
    //解决办法：
    //在项目的Build path中先移除JRE System Library，再添加库JRE System Library，重新编译后就一切正常了。
    String AES_encode = new String(Base64.getEncoder().encodeToString(byte_AES));
    //8.将字符串返回
    return AES_encode;
    } 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();
    } catch (UnsupportedEncodingException e) {
    e.printStackTrace();
    }

    //如果有错就返加nulll
    return null;
    }

  /*

  • 解密

  • 解密过程：

  • 1.同加密1-4步

  • 2.将加密后的字符串反纺成byte[]数组

  • 3.将加密内容解密
    /
    public static String AESDncode(String encodeRules, String content) {
    try {
    //1.获得原始对称密钥的字节数组
    byte[] raw = generatorKey(encodeRules);
    //2.根据字节数组生成AES密钥
    SecretKey key = new SecretKeySpec(raw, “AES”);
    //3.根据指定算法AES自成密码器
    Cipher cipher = Cipher.getInstance(“AES”);
    //4.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密(Decrypt_mode)操作，第二个参数为使用的KEY
    cipher.init(Cipher.DECRYPT_MODE, key);
    //5.将加密并编码后的内容解码成字节数组
    byte[] byte_content = Base64.getDecoder().decode(content.getBytes());;
    /
    * 解密
    */
    byte[] byte_decode = cipher.doFinal(byte_content);
    String AES_decode = new String(byte_decode, “utf-8”);
    return AES_decode;
    } catch (NoSuchAlgorithmException e) {
    e.printStackTrace();
    } catch (NoSuchPaddingException e) {
    e.printStackTrace();
    } catch (InvalidKeyException e) {
    e.printStackTrace();
    } catch (IOException e) {
    e.printStackTrace();
    } catch (IllegalBlockSizeException e) {
    e.printStackTrace();
    } catch (BadPaddingException e) {
    e.printStackTrace();
    }

    //如果有错就返加nulll
    return null;
    }

}