des算法java代码实现密钥明文用户输入

以下是DES算法的Java代码实现，其中包括了密钥和明文的用户输入：

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
import java.util.Scanner;

public class DES {

    private static final String ALGORITHM = "DES";
    private static final String MODE = "ECB";
    private static final String PADDING = "PKCS5Padding";

    public static void main(String[] args) throws Exception {
        Scanner scanner = new Scanner(System.in);

        // 获取密钥
        System.out.print("请输入8位密钥：");
        String key = scanner.nextLine();
        byte[] keyBytes = key.getBytes();

        // 获取明文
        System.out.print("请输入明文：");
        String plaintext = scanner.nextLine();
        byte[] plaintextBytes = plaintext.getBytes();

        // 加密
        byte[] ciphertextBytes = encrypt(keyBytes, plaintextBytes);

        // 将密文转换为Base64字符串
        String ciphertext = Base64.getEncoder().encodeToString(ciphertextBytes);
        System.out.println("加密后的密文：" + ciphertext);

        // 解密
        byte[] decryptedBytes = decrypt(keyBytes, Base64.getDecoder().decode(ciphertext));

        // 将解密后的明文转换为字符串
        String decryptedPlaintext = new String(decryptedBytes);
        System.out.println("解密后的明文：" + decryptedPlaintext);
    }

    /**
     * 加密
     *
     * @param keyBytes      密钥
     * @param plaintextBytes 明文
     * @return 密文
     * @throws Exception
     */
    public static byte[] encrypt(byte[] keyBytes, byte[] plaintextBytes) throws Exception {
        SecretKeySpec key = new SecretKeySpec(keyBytes, ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM + "/" + MODE + "/" + PADDING);
        cipher.init(Cipher.ENCRYPT_MODE, key);
        return cipher.doFinal(plaintextBytes);
    }

    /**
     * 解密
     *
     * @param keyBytes       密钥
     * @param ciphertextBytes 密文
     * @return 明文
     * @throws Exception
     */
    public static byte[] decrypt(byte[] keyBytes, byte[] ciphertextBytes) throws Exception {
        SecretKeySpec key = new SecretKeySpec(keyBytes, ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM + "/" + MODE + "/" + PADDING);
        cipher.init(Cipher.DECRYPT_MODE, key);
        return cipher.doFinal(ciphertextBytes);
    }
}

在这个实现中，我们使用了Java中的`Scanner`来获取用户输入的密钥和明文。我们将密钥和明文都转换为字节数组，然后调用`encrypt`方法加密，再将密文转换为Base64字符串输出。接着，我们调用`decrypt`方法解密密文，将解密后的明文转换为字符串输出。