/*
* Copyright 2012 Google Inc. All Rights Reserved.
*
* 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.google.appengine.tools.cloudstorage.oauth;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.appengine.api.urlfetch.HTTPHeader;
import com.google.appengine.api.urlfetch.HTTPRequest;
import com.google.appengine.api.urlfetch.HTTPResponse;
import com.google.appengine.api.urlfetch.URLFetchService;
import com.google.appengine.tools.cloudstorage.ExceptionHandler;
import com.google.appengine.tools.cloudstorage.RetryHelper;
import com.google.appengine.tools.cloudstorage.RetryHelperException;
import com.google.appengine.tools.cloudstorage.RetryParams;
import com.google.apphosting.api.ApiProxy.ApiDeadlineExceededException;
import com.google.apphosting.api.ApiProxy.RPCFailedException;
import com.google.apphosting.api.ApiProxy.UnknownException;
import com.google.common.util.concurrent.Futures;
import java.io.IOException;
import java.util.concurrent.Callable;
import java.util.concurrent.Future;
/**
* An OAuthURLFetchService decorator that adds the authorization header to the http request.
*
*/
abstract class AbstractOAuthURLFetchService implements OAuthURLFetchService {
private final URLFetchService urlFetch;
private static final ExceptionHandler EXCEPTION_HANDLER = new ExceptionHandler.Builder().retryOn(
UnknownException.class, RPCFailedException.class, ApiDeadlineExceededException.class).build();
private static final RetryParams RETRY_PARAMS =
new RetryParams.Builder().initialRetryDelayMillis(10).totalRetryPeriodMillis(10000).build();
AbstractOAuthURLFetchService(URLFetchService urlFetch) {
this.urlFetch = checkNotNull(urlFetch);
}
protected abstract String getToken();
private HTTPRequest createAuthorizeRequest(final HTTPRequest req) throws RetryHelperException {
String token = RetryHelper.runWithRetries(new Callable<String>() {
@Override
public String call() {
return getToken();
}
}, RETRY_PARAMS, EXCEPTION_HANDLER);
HTTPRequest request = URLFetchUtils.copyRequest(req);
request.setHeader(new HTTPHeader("Authorization", "Bearer " + token));
return request;
}
@Override
public HTTPResponse fetch(HTTPRequest req) throws IOException, RetryHelperException {
HTTPRequest authorizedRequest = createAuthorizeRequest(req);
return urlFetch.fetch(authorizedRequest);
}
@Override
public Future<HTTPResponse> fetchAsync(HTTPRequest req) {
HTTPRequest authorizedRequest;
try {
authorizedRequest = createAuthorizeRequest(req);
} catch (RetryHelperException e) {
return Futures.immediateFailedCheckedFuture(e);
}
return urlFetch.fetchAsync(authorizedRequest);
}
}