java实现的AES加密算法完整实例

本文实例讲述了java实现的AES加密算法。分享给大家供大家参考，具体如下：

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import android.util.base64;

public class AESCrypt {
  private final Cipher cipher;
  private final SecretKeySpec key;
  private AlgorithmParameterSpec spec;
  public static final String SEED_16_CHARACTER = "U1MjU1M0FDOUZ.Qz";
  public AESCrypt() throws Exception {
    // hash password with SHA-256 and crop the output to 128-bit for key
    MessageDigest digest = MessageDigest.getInstance("SHA-256");
    digest.update(SEED_16_CHARACTER.getBytes("UTF-8"));
    byte[] keyBytes = new byte[32];
    System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);
    cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
    key = new SecretKeySpec(keyBytes, "AES");
    spec = getIV();
  }
  public AlgorithmParameterSpec getIV() {
    byte[] iv = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
    IvParameterSpec ivParameterSpec;
    ivParameterSpec = new IvParameterSpec(iv);
    return ivParameterSpec;
  }
  public String encrypt(String plainText) throws Exception {
    cipher.init(Cipher.ENCRYPT_MODE, key, spec);
    byte[] encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
    String encryptedText = new String(base64.encode(encrypted,
 base64.DEFAULT), "UTF-8");
    return encryptedText;
  }
  public String decrypt(String cryptedText) throws Exception {
    cipher.init(Cipher.DECRYPT_MODE, key, spec);
    byte[] bytes = base64.decode(cryptedText, base64.DEFAULT);
    byte[] decrypted = cipher.doFinal(bytes);
    String decryptedText = new String(decrypted, "UTF-8");
    return decryptedText;
  }
}

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在线散列/哈希算法加密工具：
http://tools.jb51.net/password/hash_encrypt

希望本文所述对大家java程序设计有所帮助。