/*
* Copyright (c) 2010-2013 Mark Allen.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.restfb;
import static com.restfb.util.StringUtils.isBlank;
import static com.restfb.util.StringUtils.trimToEmpty;
import static com.restfb.util.UrlUtils.urlEncode;
import static java.util.Arrays.asList;
import java.util.HashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.logging.Logger;
import com.restfb.exception.FacebookException;
import com.restfb.exception.FacebookExceptionMapper;
import com.restfb.exception.FacebookJsonMappingException;
import com.restfb.exception.FacebookOAuthException;
import com.restfb.exception.FacebookResponseStatusException;
import com.restfb.json.JsonException;
import com.restfb.json.JsonObject;
/**
* Base class that contains data and functionality common to {@link DefaultFacebookClient} and
* {@link DefaultLegacyFacebookClient}.
*
* @author <a href="http://restfb.com">Mark Allen</a>
* @since 1.5
*/
abstract class BaseFacebookClient {
/**
* Handles {@code GET}s and {@code POST}s to the Facebook API endpoint.
*/
protected WebRequestor webRequestor;
/**
* Handles mapping Facebook response JSON to Java objects.
*/
protected JsonMapper jsonMapper;
/**
* Knows how to map Old REST API exceptions to formal Java exception types.
*/
protected FacebookExceptionMapper legacyFacebookExceptionMapper;
/**
* Set of parameter names that user must not specify themselves, since we use these parameters internally.
*/
protected final Set<String> illegalParamNames = new HashSet<String>();
/**
* Set of API calls that can use the read-only endpoint for a performance boost.
*/
protected final Set<String> readOnlyApiCalls = new HashSet<String>();
/**
* Legacy API error response 'error_code' attribute name.
*/
protected static final String LEGACY_ERROR_CODE_ATTRIBUTE_NAME = "error_code";
/**
* Legacy API error response 'error_msg' attribute name.
*/
protected static final String LEGACY_ERROR_MSG_ATTRIBUTE_NAME = "error_msg";
/**
* Reserved access token parameter name.
*/
protected static final String ACCESS_TOKEN_PARAM_NAME = "access_token";
/**
* Logger.
*/
protected final Logger logger = Logger.getLogger(getClass().getName());
/**
* Initializes this Facebook client.
*/
public BaseFacebookClient() {
initializeReadOnlyApiCalls();
legacyFacebookExceptionMapper = createLegacyFacebookExceptionMapper();
}
/**
* Specifies how we map Old REST API exception types/messages to real Java exceptions.
* <p>
* Uses an instance of {@link DefaultLegacyFacebookExceptionMapper} by default.
*
* @return An instance of the exception mapper we should use.
* @since 1.6.3
*/
protected FacebookExceptionMapper createLegacyFacebookExceptionMapper() {
return new DefaultLegacyFacebookExceptionMapper();
}
/**
* A canned implementation of {@code FacebookExceptionMapper} that maps Old REST API exceptions.
*
* @author <a href="http://restfb.com">Mark Allen</a>
* @since 1.6.3
*/
protected static class DefaultLegacyFacebookExceptionMapper implements FacebookExceptionMapper {
/**
* Invalid OAuth 2.0 Access Token error code.
* <p>
* See http://www.takwing.idv.hk/tech/fb_dev/faq/general/gen_10.html
*/
protected static final int API_EC_PARAM_ACCESS_TOKEN = 190;
/**
* @see com.restfb.exception.FacebookExceptionMapper#exceptionForTypeAndMessage(java.lang.Integer,
* java.lang.Integer, java.lang.String, java.lang.String)
*/
@Override
public FacebookException exceptionForTypeAndMessage(Integer errorCode, Integer httpStatusCode, String type,
String message) {
if (errorCode == API_EC_PARAM_ACCESS_TOKEN)
return new FacebookOAuthException(String.valueOf(errorCode), message, errorCode, httpStatusCode);
// Don't recognize this exception type? Just go with the standard
// FacebookResponseStatusException.
return new FacebookResponseStatusException(errorCode, message);
}
}
/**
* Stores off the set of API calls that support the read-only endpoint.
* <p>
* This list was cribbed from the <a href="https://github.com/facebook/php-sdk/blob/master/src/facebook.php"
* target="_blank">Official PHP Facebook API client</a>.
*
* @since 1.6.3
*/
protected void initializeReadOnlyApiCalls() {
readOnlyApiCalls.addAll(asList(new String[] { "admin.getallocation", "admin.getappproperties",
"admin.getbannedusers", "admin.getlivestreamvialink", "admin.getmetrics", "admin.getrestrictioninfo",
"application.getpublicinfo", "auth.getapppublickey", "auth.getsession", "auth.getsignedpublicsessiondata",
"comments.get", "connect.getunconnectedfriendscount", "dashboard.getactivity", "dashboard.getcount",
"dashboard.getglobalnews", "dashboard.getnews", "dashboard.multigetcount", "dashboard.multigetnews",
"data.getcookies", "events.get", "events.getmembers", "fbml.getcustomtags", "feed.getappfriendstories",
"feed.getregisteredtemplatebundlebyid", "feed.getregisteredtemplatebundles", "fql.multiquery", "fql.query",
"friends.arefriends", "friends.get", "friends.getappusers", "friends.getlists", "friends.getmutualfriends",
"gifts.get", "groups.get", "groups.getmembers", "intl.gettranslations", "links.get", "notes.get",
"notifications.get", "pages.getinfo", "pages.isadmin", "pages.isappadded", "pages.isfan",
"permissions.checkavailableapiaccess", "permissions.checkgrantedapiaccess", "photos.get", "photos.getalbums",
"photos.gettags", "profile.getinfo", "profile.getinfooptions", "stream.get", "stream.getcomments",
"stream.getfilters", "users.getinfo", "users.getloggedinuser", "users.getstandardinfo",
"users.hasapppermission", "users.isappuser", "users.isverified", "video.getuploadlimits" }));
}
/**
* If the {@code error_code} JSON field is present, we've got a response status error for this API call. Extracts
* relevant information from the JSON and throws an exception which encapsulates it for end-user consumption.
*
* @param json
* The JSON returned by Facebook in response to an API call.
* @param httpStatusCode
* The HTTP status code returned by the server, e.g. 500.
* @throws FacebookResponseStatusException
* If the JSON contains an error code.
* @throws FacebookJsonMappingException
* If an error occurs while processing the JSON.
*/
protected void throwLegacyFacebookResponseStatusExceptionIfNecessary(String json, Integer httpStatusCode) {
try {
// If this is not an object, it's not an error response.
if (!json.startsWith("{"))
return;
JsonObject errorObject = null;
// We need to swallow exceptions here because it's possible to get a legit
// Facebook response that contains illegal JSON (e.g.
// users.getLoggedInUser returning 1240077) - we're only interested in
// whether or not there's an error_code field present.
try {
errorObject = new JsonObject(json);
} catch (JsonException e) {}
if (errorObject == null || !errorObject.has(LEGACY_ERROR_CODE_ATTRIBUTE_NAME))
return;
throw legacyFacebookExceptionMapper.exceptionForTypeAndMessage(
errorObject.getInt(LEGACY_ERROR_CODE_ATTRIBUTE_NAME), httpStatusCode, null,
errorObject.getString(LEGACY_ERROR_MSG_ATTRIBUTE_NAME));
} catch (JsonException e) {
throw new FacebookJsonMappingException("Unable to process the Facebook API response", e);
}
}
/**
* Appends the given {@code parameter} to the given {@code parameters} array.
*
* @param parameter
* The parameter value to append.
* @param parameters
* The parameters to which the given {@code parameter} is appended.
* @return A new array which contains both {@code parameter} and {@code parameters}.
*/
protected Parameter[] parametersWithAdditionalParameter(Parameter parameter, Parameter... parameters) {
Parameter[] updatedParameters = new Parameter[parameters.length + 1];
System.arraycopy(parameters, 0, updatedParameters, 0, parameters.length);
updatedParameters[parameters.length] = parameter;
return updatedParameters;
}
/**
* Given a map of query names to queries, verify that it contains valid data and convert it to a JSON object string.
*
* @param queries
* The query map to convert.
* @return The {@code queries} in JSON string format.
* @throws IllegalArgumentException
* If the provided {@code queries} are invalid.
*/
protected String queriesToJson(Map<String, String> queries) {
verifyParameterPresence("queries", queries);
if (queries.keySet().size() == 0)
throw new IllegalArgumentException("You must specify at least one query.");
JsonObject jsonObject = new JsonObject();
for (Entry<String, String> entry : queries.entrySet()) {
if (isBlank(entry.getKey()) || isBlank(entry.getValue()))
throw new IllegalArgumentException("Provided queries must have non-blank keys and values. " + "You provided: "
+ queries);
try {
jsonObject.put(trimToEmpty(entry.getKey()), trimToEmpty(entry.getValue()));
} catch (JsonException e) {
// Shouldn't happen unless bizarre input is provided
throw new IllegalArgumentException("Unable to convert " + queries + " to JSON.", e);
}
}
return jsonObject.toString();
}
/**
* Gets the URL-encoded version of the given {@code value} for the parameter named {@code name}.
* <p>
* Includes special-case handling for access token parameters where we check if the token is already URL-encoded - if
* so, we don't encode again. All other parameter types are always URL-encoded.
*
* @param name
* The name of the parameter whose value should be URL-encoded and returned.
* @param value
* The value of the parameter which should be URL-encoded and returned.
* @return The URL-encoded version of the given {@code value}.
*/
protected String urlEncodedValueForParameterName(String name, String value) {
// Special handling for access_token -
// '%7C' is the pipe character and will be present in any access_token
// parameter that's already URL-encoded. If we see this combination, don't
// URL-encode. Otherwise, URL-encode as normal.
return ACCESS_TOKEN_PARAM_NAME.equals(name) && value.contains("%7C") ? value : urlEncode(value);
}
/**
* Given an api call (e.g. "me" or "fql.query"), returns the correct FB API endpoint to use.
* <p>
* Useful for returning the read-only API endpoint where possible.
*
* @param apiCall
* The FB API call (Graph or Old REST API) for which we'd like an endpoint.
* @param hasAttachment
* Are we including a multipart file when making this API call?
* @return An absolute endpoint URL to communicate with.
* @since 1.6.3
*/
protected abstract String createEndpointForApiCall(String apiCall, boolean hasAttachment);
/**
* Returns the base read-only endpoint URL.
*
* @return The base read-only endpoint URL.
* @since 1.6.3
*/
protected abstract String getFacebookReadOnlyEndpointUrl();
/**
* Verifies that the provided parameter names don't collide with the ones we internally pass along to Facebook.
*
* @param parameters
* The parameters to check.
* @throws IllegalArgumentException
* If there's a parameter name collision.
*/
protected void verifyParameterLegality(Parameter... parameters) {
for (Parameter parameter : parameters)
if (illegalParamNames.contains(parameter.name))
throw new IllegalArgumentException("Parameter '" + parameter.name + "' is reserved for RestFB use - "
+ "you cannot specify it yourself.");
}
/**
* Ensures that {@code parameter} isn't {@code null} or an empty string.
*
* @param parameterName
* The name of the parameter (to be used in exception message).
* @param parameter
* The parameter to check.
* @throws IllegalArgumentException
* If {@code parameter} is {@code null} or an empty string.
*/
protected void verifyParameterPresence(String parameterName, String parameter) {
verifyParameterPresence(parameterName, (Object) parameter);
if (parameter.trim().length() == 0)
throw new IllegalArgumentException("The '" + parameterName + "' parameter cannot be an empty string.");
}
/**
* Ensures that {@code parameter} isn't {@code null}.
*
* @param parameterName
* The name of the parameter (to be used in exception message).
* @param parameter
* The parameter to check.
* @throws IllegalArgumentException
* If {@code parameter} is {@code null}.
*/
protected void verifyParameterPresence(String parameterName, Object parameter) {
if (parameter == null)
throw new NullPointerException("The '" + parameterName + "' parameter cannot be null.");
}
}