Remove toJson() from StripeJsonModel

`toJson()` was previously used in the implementation of `equals()`
(see #813). Now that it is no longer used in `equals()`, it is
no longer needed.

Remove all implementations of toJson() and rename `StripeJsonModel`
to `StripeModel`.

example/src/main/java/com/stripe/example/activity/PaymentIntentActivity.java

@@ -158,7 +158,7 @@ private void retrievePaymentIntent() {
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(
                         paymentIntent -> mPaymentIntentValue.setText(paymentIntent != null ?
-                                paymentIntent.toJson().toString() :
+                                new JSONObject(paymentIntent.toMap()).toString() :
                                 getString(R.string.error_while_retrieving_payment_intent)),
                         throwable -> Log.e(TAG, throwable.toString())
                 );
@@ -188,7 +188,8 @@ private void confirmPaymentIntent(@NonNull final Card card) {
                 .subscribe(
                         paymentIntent -> {
                             if (paymentIntent != null) {
-                                mPaymentIntentValue.setText(paymentIntent.toJson().toString());
+                                mPaymentIntentValue.setText(
+                                        new JSONObject(paymentIntent.toMap()).toString());
 
                                 if (paymentIntent.requiresAction()) {
                                     Toast.makeText(PaymentIntentActivity.this,

stripe/src/main/java/com/stripe/android/EphemeralKey.java

@@ -5,7 +5,7 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
-import com.stripe.android.model.StripeJsonModel;
+import com.stripe.android.model.StripeModel;
 import com.stripe.android.utils.ObjectUtils;
 
 import org.json.JSONArray;
@@ -26,7 +26,7 @@
  * See <a href="https://stripe.com/docs/mobile/android/standard#prepare-your-api">
  * Using Android Standard UI Components - Prepare your API</a> for more details on ephemeral keys.
  */
-abstract class EphemeralKey extends StripeJsonModel implements Parcelable {
+abstract class EphemeralKey extends StripeModel implements Parcelable {
 
     static final String FIELD_CREATED = "created";
     static final String FIELD_EXPIRES = "expires";
@@ -84,35 +84,6 @@ abstract class EphemeralKey extends StripeJsonModel implements Parcelable {
         mType = type;
     }
 
-    @NonNull
-    @Override
-    public JSONObject toJson() {
-        JSONObject jsonObject = new JSONObject();
-        JSONArray associatedObjectsArray = new JSONArray();
-        JSONObject associatedObject = new JSONObject();
-
-        try {
-            jsonObject.put(FIELD_CREATED, mCreated);
-            jsonObject.put(FIELD_EXPIRES, mExpires);
-            jsonObject.put(FIELD_OBJECT, mObject);
-            jsonObject.put(FIELD_ID, mId);
-            jsonObject.put(FIELD_SECRET, mSecret);
-            jsonObject.put(FIELD_LIVEMODE, mLiveMode);
-
-            associatedObject.put(FIELD_TYPE, mType);
-            associatedObject.put(FIELD_ID, mObjectId);
-            associatedObjectsArray.put(associatedObject);
-
-            jsonObject.put(FIELD_ASSOCIATED_OBJECTS, associatedObjectsArray);
-        } catch (JSONException impossible) {
-            // An exception can only be thrown from put operations if the key is null
-            // or the value is a non-finite number.
-            throw new IllegalArgumentException("JSONObject creation exception thrown.");
-        }
-
-        return jsonObject;
-    }
-
     @NonNull
     @Override
     public Map<String, Object> toMap() {

stripe/src/main/java/com/stripe/android/EphemeralKeyUpdateListener.java

@@ -1,7 +1,6 @@
 package com.stripe.android;
 
 import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
 
 /**
  * Represents a listener for Ephemeral Key Update events.

stripe/src/main/java/com/stripe/android/IssuingCardPinService.java

@@ -16,6 +16,7 @@
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  * Methods for retrieval / update of a Stripe Issuing card
@@ -149,16 +150,16 @@ public void onKeyUpdate(@NonNull IssuingCardEphemeralKey ephemeralKey,
                         null);
                 return;
             }
-            String cardId = (String) arguments.get(ARGUMENT_CARD_ID);
-            String verificationId = (String) arguments.get(ARGUMENT_VERIFICATION_ID);
-            String userOneTimeCode = (String) arguments.get(ARGUMENT_ONE_TIME_CODE);
 
+            final String cardId =
+                    (String) Objects.requireNonNull(arguments.get(ARGUMENT_CARD_ID));
+            final String verificationId =
+                    (String) Objects.requireNonNull(arguments.get(ARGUMENT_VERIFICATION_ID));
+            final String userOneTimeCode =
+                    (String) Objects.requireNonNull(arguments.get(ARGUMENT_ONE_TIME_CODE));
             try {
-                final String pin = mApiHandler.retrieveIssuingCardPin(
-                        cardId,
-                        verificationId,
-                        userOneTimeCode,
-                        ephemeralKey.getSecret());
+                final String pin = mApiHandler.retrieveIssuingCardPin(cardId, verificationId,
+                        userOneTimeCode, ephemeralKey.getSecret());
                 listener.onIssuingCardPinRetrieved(pin);
 
             } catch (InvalidRequestException e) {
@@ -218,17 +219,17 @@ public void onKeyUpdate(@NonNull IssuingCardEphemeralKey ephemeralKey,
                         null);
                 return;
             }
-            String cardId = (String) arguments.get(ARGUMENT_CARD_ID);
-            String newPin = (String) arguments.get(ARGUMENT_NEW_PIN);
-            String verificationId = (String) arguments.get(ARGUMENT_VERIFICATION_ID);
-            String userOneTimeCode = (String) arguments.get(ARGUMENT_ONE_TIME_CODE);
 
+            final String cardId =
+                    (String) Objects.requireNonNull(arguments.get(ARGUMENT_CARD_ID));
+            final String newPin =
+                    (String) Objects.requireNonNull(arguments.get(ARGUMENT_NEW_PIN));
+            final String verificationId =
+                    (String) Objects.requireNonNull(arguments.get(ARGUMENT_VERIFICATION_ID));
+            final String userOneTimeCode =
+                    (String) Objects.requireNonNull(arguments.get(ARGUMENT_ONE_TIME_CODE));
             try {
-                mApiHandler.updateIssuingCardPin(
-                        cardId,
-                        newPin,
-                        verificationId,
-                        userOneTimeCode,
+                mApiHandler.updateIssuingCardPin(cardId, newPin, verificationId, userOneTimeCode,
                         ephemeralKey.getSecret());
                 listener.onIssuingCardPinUpdated();
             } catch (InvalidRequestException e) {

stripe/src/main/java/com/stripe/android/model/Address.java

@@ -20,13 +20,12 @@
 import java.util.Map;
 
 import static com.stripe.android.model.StripeJsonUtils.optString;
-import static com.stripe.android.model.StripeJsonUtils.putStringIfNotNull;
 
 /**
  * Model for an owner <a href="https://stripe.com/docs/api#source_object-owner-address">address</a>
  * object in the Source api.
  */
-public final class Address extends StripeJsonModel implements Parcelable {
+public final class Address extends StripeModel implements Parcelable {
 
     @IntDef({
             RequiredBillingAddressFields.NONE,
@@ -141,19 +140,6 @@ public Map<String, Object> toMap() {
         return map;
     }
 
-    @NonNull
-    @Override
-    public JSONObject toJson() {
-        final JSONObject jsonObject = new JSONObject();
-        putStringIfNotNull(jsonObject, FIELD_CITY, mCity);
-        putStringIfNotNull(jsonObject, FIELD_COUNTRY, mCountry);
-        putStringIfNotNull(jsonObject, FIELD_LINE_1, mLine1);
-        putStringIfNotNull(jsonObject, FIELD_LINE_2, mLine2);
-        putStringIfNotNull(jsonObject, FIELD_POSTAL_CODE, mPostalCode);
-        putStringIfNotNull(jsonObject, FIELD_STATE, mState);
-        return jsonObject;
-    }
-
     @Nullable
     public static Address fromString(@Nullable String jsonString) {
         try {

stripe/src/main/java/com/stripe/android/model/Card.java

@@ -30,14 +30,11 @@
 import static com.stripe.android.model.StripeJsonUtils.optHash;
 import static com.stripe.android.model.StripeJsonUtils.optInteger;
 import static com.stripe.android.model.StripeJsonUtils.optString;
-import static com.stripe.android.model.StripeJsonUtils.putIntegerIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putStringHashIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putStringIfNotNull;
 
 /**
  * A model object representing a Card in the Android SDK.
  */
-public final class Card extends StripeJsonModel implements StripePaymentSource {
+public final class Card extends StripeModel implements StripePaymentSource {
 
     @Retention(RetentionPolicy.SOURCE)
     @StringDef({
@@ -790,36 +787,6 @@ public String getCvcCheck() {
         return cvcCheck;
     }
 
-    @NonNull
-    @Override
-    public JSONObject toJson() {
-        final JSONObject object = new JSONObject();
-        putStringIfNotNull(object, FIELD_NAME, name);
-        putStringIfNotNull(object, FIELD_ADDRESS_CITY, addressCity);
-        putStringIfNotNull(object, FIELD_ADDRESS_COUNTRY, addressCountry);
-        putStringIfNotNull(object, FIELD_ADDRESS_LINE1, addressLine1);
-        putStringIfNotNull(object, FIELD_ADDRESS_LINE1_CHECK, addressLine1Check);
-        putStringIfNotNull(object, FIELD_ADDRESS_LINE2, addressLine2);
-        putStringIfNotNull(object, FIELD_ADDRESS_STATE, addressState);
-        putStringIfNotNull(object, FIELD_ADDRESS_ZIP, addressZip);
-        putStringIfNotNull(object, FIELD_ADDRESS_ZIP_CHECK, addressZipCheck);
-        putStringIfNotNull(object, FIELD_BRAND, brand);
-        putStringIfNotNull(object, FIELD_CURRENCY, currency);
-        putStringIfNotNull(object, FIELD_COUNTRY, country);
-        putStringIfNotNull(object, FIELD_CUSTOMER, customerId);
-        putIntegerIfNotNull(object, FIELD_EXP_MONTH, expMonth);
-        putIntegerIfNotNull(object, FIELD_EXP_YEAR, expYear);
-        putStringIfNotNull(object, FIELD_FINGERPRINT, fingerprint);
-        putStringIfNotNull(object, FIELD_FUNDING, funding);
-        putStringIfNotNull(object, FIELD_CVC_CHECK, cvcCheck);
-        putStringIfNotNull(object, FIELD_LAST4, last4);
-        putStringIfNotNull(object, FIELD_ID, id);
-        putStringIfNotNull(object, FIELD_TOKENIZATION_METHOD, tokenizationMethod);
-        putStringHashIfNotNull(object, FIELD_METADATA, metadata);
-        putStringIfNotNull(object, FIELD_OBJECT, VALUE_CARD);
-        return object;
-    }
-
     @NonNull
     @Override
     public Map<String, Object> toMap() {

stripe/src/main/java/com/stripe/android/model/Customer.java

@@ -19,15 +19,11 @@
 import static com.stripe.android.model.StripeJsonUtils.optBoolean;
 import static com.stripe.android.model.StripeJsonUtils.optInteger;
 import static com.stripe.android.model.StripeJsonUtils.optString;
-import static com.stripe.android.model.StripeJsonUtils.putBooleanIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putIntegerIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putObjectIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putStringIfNotNull;
 
 /**
  * Model for a Stripe Customer object
  */
-public final class Customer extends StripeJsonModel {
+public final class Customer extends StripeModel {
 
     private static final String FIELD_ID = "id";
     private static final String FIELD_OBJECT = "object";
@@ -83,6 +79,7 @@ public List<CustomerSource> getSources() {
         return mSources;
     }
 
+    @Nullable
     public Boolean getHasMore() {
         return mHasMore;
     }
@@ -105,50 +102,26 @@ public CustomerSource getSourceById(@NonNull String sourceId) {
         return null;
     }
 
-    @NonNull
-    @Override
-    public JSONObject toJson() {
-        JSONObject jsonObject = new JSONObject();
-        putStringIfNotNull(jsonObject, FIELD_ID, mId);
-        putStringIfNotNull(jsonObject, FIELD_OBJECT, VALUE_CUSTOMER);
-        putStringIfNotNull(jsonObject, FIELD_DEFAULT_SOURCE, mDefaultSource);
-        StripeJsonModel.putStripeJsonModelIfNotNull(jsonObject,
-                FIELD_SHIPPING,
-                mShippingInformation);
-        JSONObject sourcesObject = new JSONObject();
-        putStringIfNotNull(sourcesObject, FIELD_OBJECT, VALUE_LIST);
-        putBooleanIfNotNull(sourcesObject, FIELD_HAS_MORE, mHasMore);
-        putIntegerIfNotNull(sourcesObject, FIELD_TOTAL_COUNT, mTotalCount);
-        putStripeJsonModelListIfNotNull(sourcesObject, FIELD_DATA, mSources);
-        putStringIfNotNull(sourcesObject, FIELD_URL, mUrl);
-
-        putObjectIfNotNull(jsonObject, FIELD_SOURCES, sourcesObject);
-
-        return jsonObject;
-    }
-
     @NonNull
     @Override
     public Map<String, Object> toMap() {
         final AbstractMap<String, Object> map = new HashMap<>();
         map.put(FIELD_ID, mId);
         map.put(FIELD_OBJECT, VALUE_CUSTOMER);
         map.put(FIELD_DEFAULT_SOURCE, mDefaultSource);
-
-        StripeJsonModel.putStripeJsonModelMapIfNotNull(
-                map,
-                FIELD_SHIPPING,
-                mShippingInformation);
+        map.put(FIELD_SHIPPING, mShippingInformation != null ? mShippingInformation.toMap() : null);
 
         final AbstractMap<String, Object> sourcesObject = new HashMap<>();
         sourcesObject.put(FIELD_HAS_MORE, mHasMore);
         sourcesObject.put(FIELD_TOTAL_COUNT, mTotalCount);
         sourcesObject.put(FIELD_OBJECT, VALUE_LIST);
         sourcesObject.put(FIELD_URL, mUrl);
-        StripeJsonModel.putStripeJsonModelListIfNotNull(
-                sourcesObject,
-                FIELD_DATA,
-                mSources);
+
+        final List<Map<String, Object>> customerSourceMaps = new ArrayList<>(mSources.size());
+        for (CustomerSource customerSource : mSources) {
+            customerSourceMaps.add(customerSource.toMap());
+        }
+        sourcesObject.put(FIELD_DATA, customerSourceMaps);
         StripeNetworkUtils.removeNullAndEmptyParams(sourcesObject);
 
         map.put(FIELD_SOURCES, sourcesObject);

stripe/src/main/java/com/stripe/android/model/CustomerSource.java

@@ -16,7 +16,7 @@
 /**
  * Model of the "data" object inside a {@link Customer} "source" object.
  */
-public final class CustomerSource extends StripeJsonModel implements StripePaymentSource {
+public final class CustomerSource extends StripeModel implements StripePaymentSource {
 
     @NonNull private final StripePaymentSource mStripePaymentSource;
 
@@ -121,17 +121,6 @@ public Map<String, Object> toMap() {
         return new HashMap<>();
     }
 
-    @NonNull
-    @Override
-    public JSONObject toJson() {
-        if (mStripePaymentSource instanceof Source) {
-            return ((Source) mStripePaymentSource).toJson();
-        } else if (mStripePaymentSource instanceof Card) {
-            return ((Card) mStripePaymentSource).toJson();
-        }
-        return new JSONObject();
-    }
-
     @Override
     public boolean equals(@Nullable Object obj) {
         return this == obj || (obj instanceof CustomerSource && typedEquals((CustomerSource) obj));

stripe/src/main/java/com/stripe/android/model/PaymentIntent.java

@@ -19,17 +19,11 @@
 import java.util.Map;
 import java.util.Objects;
 
-import static com.stripe.android.model.StripeJsonUtils.listToJsonArray;
 import static com.stripe.android.model.StripeJsonUtils.optBoolean;
 import static com.stripe.android.model.StripeJsonUtils.optCurrency;
 import static com.stripe.android.model.StripeJsonUtils.optLong;
 import static com.stripe.android.model.StripeJsonUtils.optMap;
 import static com.stripe.android.model.StripeJsonUtils.optString;
-import static com.stripe.android.model.StripeJsonUtils.putArrayIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putBooleanIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putLongIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putMapIfNotNull;
-import static com.stripe.android.model.StripeJsonUtils.putStringIfNotNull;
 
 /**
  * A PaymentIntent tracks the process of collecting a payment from your customer.
@@ -39,7 +33,7 @@
  * <li><a href="https://stripe.com/docs/api/payment_intents">PaymentIntents API</a></li>
  * </ul>
  */
-public final class PaymentIntent extends StripeJsonModel {
+public final class PaymentIntent extends StripeModel {
     private static final String VALUE_PAYMENT_INTENT = "payment_intent";
 
     static final String FIELD_ID = "id";
@@ -328,30 +322,6 @@ private static List<String> jsonArrayToList(@Nullable JSONArray jsonArray) {
         return list;
     }
 
-    @NonNull
-    @Override
-    public JSONObject toJson() {
-        final JSONObject jsonObject = new JSONObject();
-        putStringIfNotNull(jsonObject, FIELD_ID, mId);
-        putStringIfNotNull(jsonObject, FIELD_OBJECT, mObjectType);
-        putArrayIfNotNull(jsonObject, FIELD_PAYMENT_METHOD_TYPES,
-                listToJsonArray(mPaymentMethodTypes));
-        putLongIfNotNull(jsonObject, FIELD_AMOUNT, mAmount);
-        putLongIfNotNull(jsonObject, FIELD_CANCELED, mCanceledAt);
-        putStringIfNotNull(jsonObject, FIELD_CAPTURE_METHOD, mCaptureMethod);
-        putStringIfNotNull(jsonObject, FIELD_CLIENT_SECRET, mClientSecret);
-        putStringIfNotNull(jsonObject, FIELD_CONFIRMATION_METHOD, mConfirmationMethod);
-        putLongIfNotNull(jsonObject, FIELD_CREATED, mCreated);
-        putStringIfNotNull(jsonObject, FIELD_CURRENCY, mCurrency);
-        putStringIfNotNull(jsonObject, FIELD_DESCRIPTION, mDescription);
-        putBooleanIfNotNull(jsonObject, FIELD_LIVEMODE, mLiveMode);
-        putMapIfNotNull(jsonObject, FIELD_NEXT_ACTION, mNextAction);
-        putStringIfNotNull(jsonObject, FIELD_RECEIPT_EMAIL, mReceiptEmail);
-        putStringIfNotNull(jsonObject, FIELD_SOURCE, mSource);
-        putStringIfNotNull(jsonObject, FIELD_STATUS, mStatus != null ? mStatus.code : null);
-        return jsonObject;
-    }
-
     @NonNull
     @Override
     public Map<String, Object> toMap() {