JCE实例快速上手 - 字节级别加解密文本

package jce;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.BadPaddingException;
import java.security.Key;
import java.security.Security;
import java.security.NoSuchAlgorithmException;
import java.security.InvalidKeyException;
public class DESCryptoTest {
    public static void main(String[] args) {
        //此为动态加载的办法；
        //静态加载方法为：编辑文件<java-home>\jre\lib\security\java.security 
     //JDK1.4及以上版本已带JCE
     //Security.addProvider(new com.sun.crypto.provider.SunJCE());
        try {
         //产生密钥(key)生成器生成密钥
            KeyGenerator kg = KeyGenerator.getInstance("DES");
            Key key = kg.generateKey();
            //产生加密器（Cipher）
            Cipher cipher = Cipher.getInstance("DES");

            byte[] data = "Hello World!".getBytes();
            System.out.println("Original data : " + new String(data));

            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] result = cipher.doFinal(data);
            System.out.println("Encrypted data: " + new String(result));

            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] original = cipher.doFinal(result);
            System.out.println("Decrypted data: " + new String(original));
        }
        catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        catch (NoSuchPaddingException e) {
            e.printStackTrace();
        }
        catch (InvalidKeyException e) {
            e.printStackTrace();
        }
        catch (IllegalStateException e) {
            e.printStackTrace();
        }
        catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        }
        catch (BadPaddingException e) {
            e.printStackTrace();
        }
    }
}