How to create a Facebook key hash?

Question

In the Facebook android tutorial we are told to use following code to create a key hash:

keytool -exportcert -alias androiddebugkey -keystore ~/.andro

Answer 1

 /**
     * Generates the hash key used for Facebook console to register app. It can also be used for other sdks) Method copied from: https://developers.facebook.com/docs/android/getting-started/
     */
    public static String printHashKey(Context ctx) {
        // Add code to print out the key hash
        try {
            PackageInfo info = ctx.getPackageManager().getPackageInfo(ctx.getPackageName(), PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                return Base64.encodeToString(md.digest(), Base64.DEFAULT);
            }
        } catch (NameNotFoundException e) {
            return "SHA-1 generation: the key count not be generated: NameNotFoundException thrown";
        } catch (NoSuchAlgorithmException e) {
            return "SHA-1 generation: the key count not be generated: NoSuchAlgorithmException thrown";
        }

        return "SHA-1 generation: epic failed";
    }