请给我java实现的完整des加密算法

以下是一个Java实现的完整DES加密算法：

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.SecureRandom;
import java.util.Base64;

public class DESUtil {

    // 生成DES密钥
    public static String generateKey() throws Exception {
        KeyGenerator keyGenerator = KeyGenerator.getInstance("DES");
        keyGenerator.init(new SecureRandom());
        SecretKey secretKey = keyGenerator.generateKey();
        return Base64.getEncoder().encodeToString(secretKey.getEncoded());
    }

    // DES加密
    public static String encrypt(String plainText, String key) throws Exception {
        byte[] keyBytes = Base64.getDecoder().decode(key);
        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "DES");
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, keySpec);
        byte[] encryptedBytes = cipher.doFinal(plainText.getBytes());
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }

    // DES解密
    public static String decrypt(String cipherText, String key) throws Exception {
        byte[] keyBytes = Base64.getDecoder().decode(key);
        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "DES");
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, keySpec);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(cipherText));
        return new String(decryptedBytes);
    }

    public static void main(String[] args) throws Exception {
        String plainText = "Hello, World!";
        String key = generateKey();
        String cipherText = encrypt(plainText, key);
        String decryptedText = decrypt(cipherText, key);
        System.out.println("Plain Text: " + plainText);
        System.out.println("Key: " + key);
        System.out.println("Cipher Text: " + cipherText);
        System.out.println("Decrypted Text: " + decryptedText);
    }
}

这个实现使用了Java标准库中的javax.crypto包来实现DES加密和解密。generateKey()方法使用KeyGenerator来生成一个随机的DES密钥，并使用Base64编码后返回。encrypt()方法使用SecretKeySpec和Cipher来实现DES加密，并使用Base64编码后返回结果。decrypt()方法使用SecretKeySpec和Cipher来实现DES解密，并将结果转换为字符串返回。在main()方法中，我们使用这些方法来加密和解密一段文本。