private byte[] getSign(Context context) { PackageManager pm = context.getPackageManager(); List<PackageInfo> apps = pm  .getInstalledPackages(PackageManager.GET_SIGNATURES); Iterator<PackageInfo> iter = apps.iterator(); while (iter.hasNext()) {  PackageInfo info = iter.next();  String packageName = info.packageName;  //按包名 取簽名  if (packageName.equals("com.test.test")) {  return info.signatures[0].toByteArray();  }  } return null;}

public static String getPublicKey(byte[] signature) {try {  CertificateFactory certFactory = CertificateFactory   .getInstance("X.509");  X509Certificate cert = (X509Certificate) certFactory   .generateCertificate(new ByteArrayInputStream(signature));  String publickey = cert.getPublicKey().toString();  publickey = publickey.substring(publickey.indexOf("modulus: ") + 9,   publickey.indexOf("/n", publickey.indexOf("modulus:")));  Log.d("TRACK", publickey);  return publickey; } catch (CertificateException e) {  e.printStackTrace(); } return null;}