com.spotify.apollo.http.client.TransformingCallback.java Source code

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Here is the source code for com.spotify.apollo.http.client.TransformingCallback.java

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/*
 * -\-\-
 * Spotify Apollo okhttp Client Module
 * --
 * Copyright (C) 2013 - 2015 Spotify AB
 * --
 * 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 com.spotify.apollo.http.client;

import com.google.common.base.Joiner;

import com.spotify.apollo.Response;
import com.spotify.apollo.Status;
import com.spotify.apollo.StatusType;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.Request;

import java.io.IOException;
import java.text.MessageFormat;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;

import okio.ByteString;

class TransformingCallback implements Callback {

    private static final Joiner HEADER_JOINER = Joiner.on(", ");

    private final CompletableFuture<Response<ByteString>> future;

    TransformingCallback(CompletableFuture<Response<ByteString>> future) {
        this.future = future;
    }

    public static TransformingCallback create(CompletableFuture<Response<ByteString>> future) {
        return new TransformingCallback(future);
    }

    @Override
    public void onFailure(Request request, IOException e) {
        final String message = MessageFormat.format("Request {0} failed", request);
        final IOException exception = new IOException(message, e);
        future.completeExceptionally(exception);
    }

    @Override
    public void onResponse(com.squareup.okhttp.Response response) throws IOException {
        future.complete(transformResponse(response));
    }

    static Response<ByteString> transformResponse(com.squareup.okhttp.Response response) throws IOException {

        final StatusType status = transformStatus(response.code(), Optional.ofNullable(response.message()));

        Response<ByteString> apolloResponse = Response.forStatus(status);

        for (Map.Entry<String, List<String>> entry : response.headers().toMultimap().entrySet()) {
            apolloResponse = apolloResponse.withHeader(entry.getKey(), HEADER_JOINER.join(entry.getValue()));
        }

        final byte[] bytes = response.body().bytes();
        if (bytes.length > 0) {
            apolloResponse = apolloResponse.withPayload(ByteString.of(bytes));
        }

        return apolloResponse;
    }

    static StatusType transformStatus(int code, Optional<String> message) {
        final StatusType statusType = Status.createForCode(code);

        if (message.isPresent() && !message.get().equals(statusType.reasonPhrase())) {
            return statusType.withReasonPhrase(message.get());
        } else {
            return statusType;
        }
    }
}