| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * 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.android.exchange.eas; |
| |
| import android.content.SyncResult; |
| |
| import com.android.exchange.Eas; |
| import com.android.exchange.EasResponse; |
| import com.android.mail.utils.LogUtils; |
| import com.google.common.collect.Sets; |
| |
| import org.apache.http.Header; |
| import org.apache.http.HttpEntity; |
| |
| import java.util.HashSet; |
| |
| /** |
| * Performs an HTTP Options request to the Exchange server, in order to get the protocol |
| * version. |
| */ |
| public class EasOptions extends EasOperation { |
| private static final String LOG_TAG = Eas.LOG_TAG; |
| |
| /** Result code indicating we successfully got a protocol version. */ |
| public static final int RESULT_OK = 1; |
| |
| /** Set of Exchange protocol versions we understand. */ |
| private static final HashSet<String> SUPPORTED_PROTOCOL_VERSIONS = Sets.newHashSet( |
| Eas.SUPPORTED_PROTOCOL_EX2003, |
| Eas.SUPPORTED_PROTOCOL_EX2007, Eas.SUPPORTED_PROTOCOL_EX2007_SP1, |
| Eas.SUPPORTED_PROTOCOL_EX2010, Eas.SUPPORTED_PROTOCOL_EX2010_SP1); |
| |
| private String mProtocolVersion = null; |
| |
| public EasOptions(final EasOperation parentOperation) { |
| super(parentOperation); |
| } |
| |
| /** |
| * Perform the server request. If successful, callers should use |
| * {@link #getProtocolVersionString} to get the actual protocol version value. |
| * @param syncResult The {@link SyncResult} to use for this operation. |
| * @return A result code; {@link #RESULT_OK} is the only value that indicates success. |
| */ |
| public int getProtocolVersionFromServer(final SyncResult syncResult) { |
| return performOperation(syncResult); |
| } |
| |
| /** |
| * @return The protocol version to use, or null if we did not successfully get one. |
| */ |
| public String getProtocolVersionString() { |
| return mProtocolVersion; |
| } |
| |
| /** |
| * Note that this operation does not actually use this name when forming the request. |
| * @return A useful name for logging this operation. |
| */ |
| @Override |
| protected String getCommand() { |
| return "OPTIONS"; |
| } |
| |
| @Override |
| protected HttpEntity getRequestEntity() { |
| return null; |
| } |
| |
| @Override |
| protected int handleResponse(final EasResponse response, final SyncResult syncResult) { |
| final Header commands = response.getHeader("MS-ASProtocolCommands"); |
| final Header versions = response.getHeader("ms-asprotocolversions"); |
| final boolean hasProtocolVersion; |
| if (commands == null || versions == null) { |
| LogUtils.e(LOG_TAG, "OPTIONS response without commands or versions"); |
| hasProtocolVersion = false; |
| } else { |
| mProtocolVersion = getProtocolVersionFromHeader(versions); |
| hasProtocolVersion = (mProtocolVersion != null); |
| } |
| if (!hasProtocolVersion) { |
| return RESULT_PROTOCOL_VERSION_UNSUPPORTED; |
| } |
| |
| return RESULT_OK; |
| } |
| |
| @Override |
| protected String getRequestUri() { |
| return null; |
| } |
| |
| /** |
| * Find the best protocol version to use from the header. |
| * @param versionHeader The {@link Header} for the server's supported versions. |
| * @return The best protocol version we mutually support, or null if none found. |
| */ |
| private String getProtocolVersionFromHeader(final Header versionHeader) { |
| // The string is a comma separated list of EAS versions in ascending order |
| // e.g. 1.0,2.0,2.5,12.0,12.1,14.0,14.1 |
| final String supportedVersions = versionHeader.getValue(); |
| LogUtils.d(LOG_TAG, "Server supports versions: %s", supportedVersions); |
| final String[] supportedVersionsArray = supportedVersions.split(","); |
| // Find the most recent version we support |
| String newProtocolVersion = null; |
| for (final String version: supportedVersionsArray) { |
| if (SUPPORTED_PROTOCOL_VERSIONS.contains(version)) { |
| newProtocolVersion = version; |
| } |
| } |
| return newProtocolVersion; |
| } |
| } |