java实现des加解密算法

Java中实现DES加解密算法可以使用Java内置的Cipher类实现。以下是一个简单的示例代码：

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class DES {
    private static final String ALGORITHM = "DES";
    private static final String TRANSFORMATION = "DES/ECB/PKCS5Padding";

    public static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        SecretKeySpec keySpec = new SecretKeySpec(key, ALGORITHM);
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.ENCRYPT_MODE, keySpec);
        return cipher.doFinal(data);
    }

    public static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        SecretKeySpec keySpec = new SecretKeySpec(key, ALGORITHM);
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.DECRYPT_MODE, keySpec);
        return cipher.doFinal(data);
    }

    public static void main(String[] args) throws Exception {
        String keyStr = "12345678";
        byte[] key = keyStr.getBytes();
        String dataStr = "Hello, DES";
        byte[] data = dataStr.getBytes();

        byte[] encryptedData = encrypt(data, key);
        System.out.println("Encrypted data: " + new String(encryptedData));

        byte[] decryptedData = decrypt(encryptedData, key);
        System.out.println("Decrypted data: " + new String(decryptedData));
    }
}

在上面的示例代码中，encrypt()方法和decrypt()方法分别用于加密和解密数据。其中，key参数为加密密钥，data参数为待加密或解密的数据。示例代码中使用的加密模式为ECB，填充方式为PKCS5Padding。在实际应用中，应该根据具体需求选择合适的加密模式和填充方式。