RequestSender.java

/*
 * Copyright 2014-2015 GameUp
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.gameup.android.http;

import com.google.gson.JsonParseException;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;

import java.io.IOException;
import java.io.Reader;
import java.net.HttpURLConnection;

import io.gameup.android.GameUpException;
import io.gameup.android.util.Utils;
import io.gameup.android.json.GsonFactory;
import lombok.AccessLevel;
import lombok.NoArgsConstructor;
import lombok.NonNull;

/**
 * Handles sending requests and parsing responses.
 */
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public class RequestSender {

    /**
     * @param request A request that isn't expected to return a response body,
     *                or where the response body should be ignored.
     */
    public static void send(final @NonNull Request request) {
        try {
            final Response response =
                    OkHttpClientFactory.getClient().newCall(request).execute();
            if (response.code() != HttpURLConnection.HTTP_OK &&
                    response.code() != HttpURLConnection.HTTP_NO_CONTENT &&
                    response.code() != HttpURLConnection.HTTP_CREATED) {
                Reader in = null;
                try {
                    in = response.body().charStream();

                    // If the response input stream is null, assume no connection.
                    if (in == null) {
                        throw new GameUpException(0, "No Connection");
                    }

                    try {
                        throw GsonFactory.get().fromJson(in, GameUpException.class);
                    }
                    catch (final JsonParseException e) {
                        throw new GameUpException(500, "Unknown error data", null);
                    }
                }
                finally {
                    Utils.closeQuietly(in);
                }
            }
        }
        catch(final IOException e) {
            throw new GameUpException(400, "Failed to execute request", null);
        }
    }

    /**
     * @param request A request.
     * @param responseType The class type to try to deserialise the body to.
     * @return An instance of the given type, or null if the response body was
     *         empty.
     */
    public static <T> T send(final @NonNull Request request,
                             final @NonNull Class<T> responseType) {
        Reader in = null;
        try {
            final Response response =
                    OkHttpClientFactory.getClient().newCall(request).execute();

            in = response.body().charStream();

            if (response.code() != HttpURLConnection.HTTP_OK &&
                    response.code() != HttpURLConnection.HTTP_NO_CONTENT &&
                    response.code() != HttpURLConnection.HTTP_CREATED) {

                // If the response input stream is null, assume no connection.
                if (in == null) {
                    throw new GameUpException(0, "No Connection");
                }

                try {
                    throw GsonFactory.get().fromJson(in, GameUpException.class);
                } catch (final JsonParseException e) {
                    throw new GameUpException(500, "Unknown error data", null);
                }
            }

            try {
                return GsonFactory.get().fromJson(in, responseType);
            }
            catch (final JsonParseException e) {
                throw new GameUpException(400,
                        "Response data does not match expected entity", null);
            }
        }
        catch(final IOException e) {
            throw new GameUpException(400, "Failed to execute request", null);
        }
        finally {
            Utils.closeQuietly(in);
        }
    }

}