Facebook 审核时要的hashset**散列

接入facebook sdk 需要审核，审核时需要根据包名获取**散列，该方法查了两次，这次记录一下，

public static String printKeyHash(Activity context) {
    PackageInfo packageInfo;
    String key = null;
    try {
        //getting application package name, as defined in manifest
        String packageName = context.getApplicationContext().getPackageName();

        //Retriving package info
        packageInfo = context.getPackageManager().getPackageInfo(packageName,
                PackageManager.GET_SIGNATURES);

        Log.e("Package Name=", context.getApplicationContext().getPackageName());

        for (Signature signature : packageInfo.signatures) {
            MessageDigest md = MessageDigest.getInstance("SHA");
            md.update(signature.toByteArray());
            key = new String(Base64.encode(md.digest(), 0));

            // String key = new String(Base64.encodeBytes(md.digest()));
            Log.e("Key Hash=", key);
        }
    } catch (PackageManager.NameNotFoundException e1) {
        Log.e("Name not found", e1.toString());
    }
    catch (NoSuchAlgorithmException e) {
        Log.e("No such an algorithm", e.toString());
    } catch (Exception e) {
        Log.e("Exception", e.toString());
    }

    return key;
}