用Java加密和解密密码

import javax.crypto.*;
import javax.crypto.spec.*;
import java.security.*;
import java.util.Base64;

public class AESDemo {
    private static final byte[] KEY_BYTES = new byte[16]; // 128-bit key

    public static void main(String[] args) {
        String plaintext = "Hello, world!";
        String encrypted = encrypt(plaintext);
        String decrypted = decrypt(encrypted);

        System.out.println("Plaintext: " + plaintext);
        System.out.println("Encrypted: " + encrypted);
        System.out.println("Decrypted: " + decrypted);
    }

    public static String encrypt(String plaintext) {
        try {
            SecretKeySpec keySpec = new SecretKeySpec(KEY_BYTES, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            byte[] iv = cipher.getParameters().getParameterSpec(IvParameterSpec.class).getIV();
            cipher.init(Cipher.ENCRYPT_MODE, keySpec, new IvParameterSpec(iv));
            byte[] ciphertext = cipher.doFinal(plaintext.getBytes());
            return Base64.getEncoder().encodeToString(iv) + ":" + Base64.getEncoder().encodeToString(ciphertext);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static String decrypt(String ciphertext) {
        try {
            String[] parts = ciphertext.split(":");
            byte[] iv = Base64.getDecoder().decode(parts[0]);
            byte[] encrypted = Base64.getDecoder().decode(parts[1]);
            SecretKeySpec keySpec = new SecretKeySpec(KEY_BYTES, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(iv));
            byte[] plaintext = cipher.doFinal(encrypted);
            return new String(plaintext);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}