com.google.android.work.emmnotifications.RetryHttpInitializerWrapper.java Source code

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Here is the source code for com.google.android.work.emmnotifications.RetryHttpInitializerWrapper.java

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/*
 * Copyright 2014 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.android.work.emmnotifications;

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.http.HttpBackOffIOExceptionHandler;
import com.google.api.client.http.HttpBackOffUnsuccessfulResponseHandler;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.HttpResponse;
import com.google.api.client.http.HttpUnsuccessfulResponseHandler;
import com.google.api.client.util.ExponentialBackOff;
import com.google.api.client.util.Sleeper;
import com.google.common.base.Preconditions;
import com.google.common.io.CharStreams;

import java.io.IOException;
import java.io.InputStreamReader;
import java.util.logging.Logger;

/**
 * RetryHttpInitializerWrapper will automatically retry upon RPC
 * failures, preserving the auto-refresh behavior of the Google
 * Credentials.
 */
public class RetryHttpInitializerWrapper implements HttpRequestInitializer {

    private static final Logger LOG = Logger.getLogger(RetryHttpInitializerWrapper.class.getName());

    // Intercepts the request for filling in the "Authorization"
    // header field, as well as recovering from certain unsuccessful
    // error codes wherein the Credential must refresh its token for a
    // retry.
    private final Credential wrappedCredential;

    // A sleeper; you can replace it with a mock in your test.
    private final Sleeper sleeper;

    public RetryHttpInitializerWrapper(Credential wrappedCredential) {
        this(wrappedCredential, Sleeper.DEFAULT);
    }

    // Use only for testing.
    RetryHttpInitializerWrapper(Credential wrappedCredential, Sleeper sleeper) {
        this.wrappedCredential = Preconditions.checkNotNull(wrappedCredential);
        this.sleeper = sleeper;
    }

    public void initialize(HttpRequest request) {
        final HttpUnsuccessfulResponseHandler backoffHandler = new HttpBackOffUnsuccessfulResponseHandler(
                new ExponentialBackOff()).setSleeper(sleeper);
        request.setInterceptor(wrappedCredential);

        request.setConnectTimeout(3 * 60000); // 3 minutes connect timeout
        request.setReadTimeout(3 * 60000); // 3 minutes read timeout

        request.setUnsuccessfulResponseHandler(new HttpUnsuccessfulResponseHandler() {
            public boolean handleResponse(HttpRequest request, HttpResponse response, boolean supportsRetry)
                    throws IOException {

                LOG.info("RetryHandler: " + CharStreams.toString(new InputStreamReader(response.getContent())));

                if (wrappedCredential.handleResponse(request, response, supportsRetry)) {
                    // If credential decides it can handle it,
                    // the return code or message indicated
                    // something specific to authentication,
                    // and no backoff is desired.

                    LOG.info("Requested: " + request.getUrl().toString());
                    return true;
                } else if (backoffHandler.handleResponse(request, response, supportsRetry)) {

                    // Otherwise, we defer to the judgement of
                    // our internal backoff handler.
                    LOG.info("Retrying " + request.getUrl());
                    return true;
                } else {
                    return false;
                }
            }
        });
        request.setIOExceptionHandler(
                new HttpBackOffIOExceptionHandler(new ExponentialBackOff()).setSleeper(sleeper));
    }
}