java aes加密工具类

以下是使用Java实现AES加密的工具类：

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

public class AESUtils {

    public static final String AES_CBC_NOPADDING = "AES/CBC/NoPadding";

    /**
     * AES加密
     *
     * @param data     待加密数据
     * @param key      密钥
     * @param iv       偏移量
     * @param mode     加密模式
     * @param encoding 编码方式
     * @return 加密后的数据
     * @throws Exception
     */
    public static String encrypt(String data, String key, String iv, String mode, String encoding) throws Exception {
        Cipher cipher = Cipher.getInstance(mode);
        int blockSize = cipher.getBlockSize();

        byte[] dataBytes = data.getBytes(encoding);
        int plaintextLength = dataBytes.length;
        if (plaintextLength % blockSize != 0) {
            plaintextLength += blockSize - (plaintextLength % blockSize);
        }

        byte[] plaintext = new byte[plaintextLength];
        System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);

        SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

        cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
        byte[] encrypted = cipher.doFinal(plaintext);

        return Base64.getEncoder().encodeToString(encrypted);
    }

    /**
     * AES解密
     *
     * @param data     待解密数据
     * @param key      密钥
     * @param iv       偏移量
     * @param mode     加密模式
     * @param encoding 编码方式
     * @return 解密后的数据
     * @throws Exception
     */
    public static String decrypt(String data, String key, String iv, String mode, String encoding) throws Exception {
        Cipher cipher = Cipher.getInstance(mode);

        SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());

        cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);
        byte[] encrypted = Base64.getDecoder().decode(data);
        byte[] original = cipher.doFinal(encrypted);

        return new String(original, encoding);
    }

    /**
     * 生成AES密钥
     *
     * @param length 密钥长度
     * @return 密钥
     * @throws Exception
     */
    public static String generateAESKey(int length) throws Exception {
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        byte[] keyBytes = md.digest("my-secret-key".getBytes("UTF-8"));
        byte[] truncatedKey = new byte[length];
        System.arraycopy(keyBytes, 0, truncatedKey, 0, length);
        return Base64.getEncoder().encodeToString(truncatedKey);
    }
}

使用示例：

public static void main(String[] args) throws Exception {
    String data = "Hello, world!";
    String key = AESUtils.generateAESKey(16); // 生成16位密钥
    String iv = "1234567890123456"; // 偏移量
    String mode = AESUtils.AES_CBC_NOPADDING; // 加密模式
    String encoding = "UTF-8"; // 编码方式

    String encrypted = AESUtils.encrypt(data, key, iv, mode, encoding);
    System.out.println("加密后的数据：" + encrypted);

    String decrypted = AESUtils.decrypt(encrypted, key, iv, mode, encoding);
    System.out.println("解密后的数据：" + decrypted);
}