Merge pull request #136 from nextcloud/etag

        ACCOUNT_USES_STANDARD_PASSWORD,

        METADATA_NOT_FOUND,

        OLD_ANDROID_API,

        UNTRUSTED_DOMAIN

        UNTRUSTED_DOMAIN,

        ETAG_CHANGED,

        ETAG_UNCHANGED

    }

    private boolean mSuccess = false;

/*

 * Nextcloud Android client application

 *

 * @author Tobias Kaminsky

 * Copyright (C) 2018 Tobias Kaminsky

 * Copyright (C) 2018 Nextcloud GmbH.

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Affero General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU Affero General Public License for more details.

 *

 * You should have received a copy of the GNU Affero General Public License

 * along with this program. If not, see <http://www.gnu.org/licenses/>.

 */

package com.owncloud.android.lib.resources.files;

import com.owncloud.android.lib.common.OwnCloudClient;

import com.owncloud.android.lib.common.network.WebdavUtils;

import com.owncloud.android.lib.common.operations.RemoteOperation;

import com.owncloud.android.lib.common.operations.RemoteOperationResult;

import com.owncloud.android.lib.common.utils.Log_OC;

import org.apache.commons.httpclient.HttpStatus;

import org.apache.jackrabbit.webdav.MultiStatusResponse;

import org.apache.jackrabbit.webdav.client.methods.PropFindMethod;

import org.apache.jackrabbit.webdav.property.DavPropertyName;

import org.apache.jackrabbit.webdav.property.DavPropertyNameSet;

/**

 * Check if file is up to date, by checking only eTag

 */

public class CheckEtagOperation extends RemoteOperation {

    private static final int SYNC_READ_TIMEOUT = 40000;

    private static final int SYNC_CONNECTION_TIMEOUT = 5000;

    private static final String TAG = CheckEtagOperation.class.getSimpleName();

    private String path;

    private String expectedEtag;

    public CheckEtagOperation(String path, String expectedEtag) {

        this.path = path;

        this.expectedEtag = expectedEtag;

    }

    @Override

    protected RemoteOperationResult run(OwnCloudClient client) {

        try {

            DavPropertyNameSet propSet = new DavPropertyNameSet();

            propSet.add(DavPropertyName.GETETAG);

            PropFindMethod propfind = new PropFindMethod(client.getWebdavUri() + WebdavUtils.encodePath(path),

                    propSet, 0);

            int status = client.executeMethod(propfind, SYNC_READ_TIMEOUT, SYNC_CONNECTION_TIMEOUT);

            if (status == HttpStatus.SC_MULTI_STATUS || status == HttpStatus.SC_OK) {

                MultiStatusResponse resp = propfind.getResponseBodyAsMultiStatus().getResponses()[0];

                String etag = WebdavUtils.parseEtag((String) resp.getProperties(HttpStatus.SC_OK)

                        .get(DavPropertyName.GETETAG).getValue());

                if (etag.equals(expectedEtag)) {

                    return new RemoteOperationResult(RemoteOperationResult.ResultCode.ETAG_UNCHANGED);

                }

            }

        } catch (Exception e) {

            Log_OC.e(TAG, "Error while retrieving eTag");

        }

        return new RemoteOperationResult(RemoteOperationResult.ResultCode.ETAG_CHANGED);

    }

}