Java实现的AES256加密解密功能示例

package com.handler;import java.io.UnsupportedEncodingException;import java.security.Key;import java.security.Security;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.spec.SecretKeySpec;public class AES256Encryption{public static final String KEY_ALGORITHM="AES";public static final String CIPHER_ALGORITHM="AES/ECB/PKCS7Padding";public static byte[] initkey() throws Exception{   //实例化密钥生成器     Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());     KeyGenerator kg=KeyGenerator.getInstance(KEY_ALGORITHM, "BC");     kg.init(256);     kg.init(128);     SecretKey secretKey=kg.generateKey();     return secretKey.getEncoded();}public static byte[] initRootKey() throws Exception{     return new byte[] { 0x08, 0x08, 0x04, 0x0b, 0x02, 0x0f, 0x0b, 0x0c,       0x01, 0x03, 0x09, 0x07, 0x0c, 0x03, 0x07, 0x0a, 0x04, 0x0f,        0x06, 0x0f, 0x0e, 0x09, 0x05, 0x01, 0x0a, 0x0a, 0x01, 0x09,       0x06, 0x07, 0x09, 0x0d };}public static Key toKey(byte[] key) throws Exception{SecretKey secretKey=new SecretKeySpec(key,KEY_ALGORITHM);return secretKey;}public static byte[] encrypt(byte[] data,byte[] key) throws Exception{  Key k=toKey(key);  Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());  Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM, "BC");  cipher.init(Cipher.ENCRYPT_MODE, k);  return cipher.doFinal(data);}public static byte[] decrypt(byte[] data,byte[] key) throws Exception{    Key k =toKey(key);    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());    Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM, "BC");    cipher.init(Cipher.DECRYPT_MODE, k);    return cipher.doFinal(data);}public static void main(String[] args) throws UnsupportedEncodingException{     String str="芸sweet";     //打印原文     System.out.println("原文："+str);     //密钥     byte[] key;     try {    //生成随机密钥       key = AES256Encryption.initkey();       //打印密钥       System.out.print("密钥：");       for(int i = 0;i        System.out.printf("%x", key[i]);       }       System.out.print("n");       //加密       byte[] data=AES256Encryption.encrypt(str.getBytes(), key);       //打印密文       System.out.print("加密后：");       for(int i = 0;i        System.out.printf("%x", data[i]);       }       System.out.print("n");       //解密密文       data=AES256Encryption.decrypt(data, key);       //打印原文       System.out.println("解密后："+new String(data));} catch (Exception e) {  e.printStackTrace();}