import org.apache.commons.codec.binary.Base64;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.spec.IvParameterSpec;import javax.crypto.spec.SecretKeySpec;import java.security.AlgorithmParameters;import java.security.Key;import java.security.Security;public class AES {  // 算法名  public static final String KEY_NAME = "AES";  // 加解密算法/模式/填充方式  // ECB模式只用密鑰即可對數據進行加密解密，CBC模式需要添加一個iv  public static final String CIPHER_ALGORITHM = "AES/CBC/PKCS7Padding";  /**   * 微信 數據解密<br/>   * 對稱解密使用的算法為 AES-128-CBC，數據采用PKCS#7填充<br/>   * 對稱解密的目標密文:encrypted=Base64_Decode(encryptData)<br/>   * 對稱解密秘鑰:key = Base64_Decode(session_key),aeskey是16字節<br/>   * 對稱解密算法初始向量:iv = Base64_Decode(iv),同樣是16字節<br/>   *   * @param encrypted 目標密文   * @param session_key 會話ID   * @param iv 加密算法的初始向量   */  public static String wxDecrypt(String encrypted, String session_key, String iv) {    String json = null;    byte[] encrypted64 = Base64.decodeBase64(encrypted);    byte[] key64 = Base64.decodeBase64(session_key);    byte[] iv64 = Base64.decodeBase64(iv);    byte[] data;    try {      init();      json = new String(decrypt(encrypted64, key64, generateIV(iv64)));    } catch (Exception e) {      e.printStackTrace();    }    return json;  }  /**   * 初始化密鑰   */  public static void init() throws Exception {    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());    KeyGenerator.getInstance(KEY_NAME).init(128);  }  /**   * 生成iv   */  public static AlgorithmParameters generateIV(byte[] iv) throws Exception {    // iv 為一個 16 字節的數組，這里采用和 iOS 端一樣的構造方法，數據全為0    // Arrays.fill(iv, (byte) 0x00);    AlgorithmParameters params = AlgorithmParameters.getInstance(KEY_NAME);    params.init(new IvParameterSpec(iv));    return params;  }  /**   * 生成解密   */  public static byte[] decrypt(byte[] encryptedData, byte[] keyBytes, AlgorithmParameters iv)      throws Exception {    Key key = new SecretKeySpec(keyBytes, KEY_NAME);    Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);    // 設置為解密模式    cipher.init(Cipher.DECRYPT_MODE, key, iv);    return cipher.doFinal(encryptedData);  }}

public String decodeUserInfo(String encrypted, String session_key, String iv) throws IOException {  String json = wxDecrypt(encrypted, session_key, iv);  System.out.println(json);  return json;}