Java中可逆的加密算法代码

在Java中，常见的可逆加密算法包括AES和DES算法。以下是一个使用AES算法进行加密解密的示例代码：

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

public class AesUtil {

    //定义加密算法，ECB模式，PKCS5Padding填充
    private static final String ALGORITHM_MODE_PADDING = "AES/CBC/PKCS5Padding";

    //定义向量，必须是16位
    private static final String IV_STRING = "1234567890123456";

    //定义密钥，必须是16位
    private static final String KEY = "1234567890123456";

    /**
     * AES加密
     * @param content 待加密的字符串
     * @return 加密后的字符串
     * @throws Exception
     */
    public static String encrypt(String content) throws Exception {
        Cipher cipher = Cipher.getInstance(ALGORITHM_MODE_PADDING);
        SecretKeySpec keySpec = new SecretKeySpec(KEY.getBytes(), "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(IV_STRING.getBytes());
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
        byte[] encrypted = cipher.doFinal(content.getBytes());
        return Base64.getEncoder().encodeToString(encrypted);
    }

    /**
     * AES解密
     * @param content 待解密的字符串
     * @return 解密后的字符串
     * @throws Exception
     */
    public static String decrypt(String content) throws Exception {
        Cipher cipher = Cipher.getInstance(ALGORITHM_MODE_PADDING);
        SecretKeySpec keySpec = new SecretKeySpec(KEY.getBytes(), "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(IV_STRING.getBytes());
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
        byte[] encrypted = Base64.getDecoder().decode(content);
        byte[] decrypted = cipher.doFinal(encrypted);
        return new String(decrypted);
    }
}

使用示例：

public static void main(String[] args) throws Exception {
    String content = "Hello, world!";
    String encrypted = AesUtil.encrypt(content);
    String decrypted = AesUtil.decrypt(encrypted);
    System.out.println("加密前：" + content);
    System.out.println("加密后：" + encrypted);
    System.out.println("解密后：" + decrypted);
}