怎么使用aes128进行加密，java

使用Java进行AES128加密的步骤如下：

1. 导入所需的包

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

2. 定义密钥和IV

String key = "1234567890abcdef"; // 16字节的密钥
String iv = "fedcba0987654321"; // 16字节的IV

3. 创建加密解密器

byte[] keyBytes = key.getBytes("UTF-8");
byte[] ivBytes = iv.getBytes("UTF-8");
SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");

4. 初始化加密解密器

cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec); // 加密模式
// cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec); // 解密模式

5. 加密数据

String plaintext = "Hello, world!";
byte[] ciphertext = cipher.doFinal(plaintext.getBytes("UTF-8"));

完整的加密代码如下：

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class AESUtil {
    public static byte[] encrypt(String key, String iv, String plaintext) throws Exception {
        byte[] keyBytes = key.getBytes("UTF-8");
        byte[] ivBytes = iv.getBytes("UTF-8");
        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
        return cipher.doFinal(plaintext.getBytes("UTF-8"));
    }
}

使用方法：

String key = "1234567890abcdef";
String iv = "fedcba0987654321";
String plaintext = "Hello, world!";
byte[] ciphertext = AESUtil.encrypt(key, iv, plaintext);