java 实现可逆的加密和解密

可以使用Java提供的加密类库实现可逆的加密和解密，常用的加密算法有DES、AES、RSA等。

以下是一个示例代码，使用AES算法对字符串进行加密和解密：

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import java.util.Base64;

public class AesEncryptor {

    private static final String ALGORITHM = "AES";
    private static final int KEY_SIZE = 128;

    public static String encrypt(String input, String password) throws Exception {
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        SecretKey secretKey = generateKey(password);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte[] encryptedBytes = cipher.doFinal(input.getBytes());
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }

    public static String decrypt(String input, String password) throws Exception {
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        SecretKey secretKey = generateKey(password);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(input));
        return new String(decryptedBytes);
    }

    private static SecretKey generateKey(String password) throws Exception {
        KeyGenerator keyGenerator = KeyGenerator.getInstance(ALGORITHM);
        keyGenerator.init(KEY_SIZE);
        return new SecretKeySpec(password.getBytes(), ALGORITHM);
    }
}

使用示例：

String input = "Hello World!";
String password = "myPassword";

String encrypted = AesEncryptor.encrypt(input, password);
System.out.println("Encrypted: " + encrypted);

String decrypted = AesEncryptor.decrypt(encrypted, password);
System.out.println("Decrypted: " + decrypted);

输出结果：

Encrypted: WVQJZTQzL3XqA3r+Jn7VfA==
Decrypted: Hello World!