JSONObjectType.java

/*
 * Copyright 2007 Yusuke Yamamoto
 *
 * 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 twitter4j.json;

import twitter4j.internal.logging.Logger;
import twitter4j.internal.org.json.JSONException;
import twitter4j.internal.org.json.JSONObject;

/**
 * @author Dan Checkoway - dcheckoway at gmail.com
 * @since Twitter4J 2.1.9
 */
public final class JSONObjectType {
    public enum Type {
        SENDER,
        STATUS,
        DIRECT_MESSAGE,
        DELETE,
        LIMIT,
        STALL_WARNING,
        SCRUB_GEO,
        FRIENDS,
        FAVORITE,
        UNFAVORITE,
        FOLLOW,
        UNFOLLOW,
        USER_LIST_MEMBER_ADDED,
        USER_LIST_MEMBER_DELETED,
        USER_LIST_SUBSCRIBED,
        USER_LIST_UNSUBSCRIBED,
        USER_LIST_CREATED,
        USER_LIST_UPDATED,
        USER_LIST_DESTROYED,
        USER_UPDATE,
        BLOCK,
        UNBLOCK,
        DISCONNECTION,
        UNKNOWN
    }


    private static final Logger logger = Logger.getLogger(JSONObjectType.class);

    /**
     * Determine the respective object type for a given JSONObject.  This
     * method inspects the object to figure out what type of object it
     * represents.  This is useful when processing JSON events of mixed type
     * from a stream, in which case you may need to know what type of object
     * to construct, or how to handle the event properly.
     *
     * @param json the JSONObject whose type should be determined
     * @return the determined JSONObjectType, or null if not recognized
     */
    public static Type determine(JSONObject json) {
        // This code originally lived in AbstractStreamImplementation.
        // I've moved it in here to expose it as a public encapsulation of
        // the object type determination logic.
        if (!json.isNull("sender")) {
            return Type.SENDER;
        } else if (!json.isNull("text")) {
            return Type.STATUS;
        } else if (!json.isNull("direct_message")) {
            return Type.DIRECT_MESSAGE;
        } else if (!json.isNull("delete")) {
            return Type.DELETE;
        } else if (!json.isNull("limit")) {
            return Type.LIMIT;
        } else if (!json.isNull("warning")) {
            return Type.STALL_WARNING;
        } else if (!json.isNull("scrub_geo")) {
            return Type.SCRUB_GEO;
        } else if (!json.isNull("friends")) {
            return Type.FRIENDS;
        } else if (!json.isNull("event")) {
            String event;
            try {
                event = json.getString("event");
                if ("favorite".equals(event)) {
                    return Type.FAVORITE;
                } else if ("unfavorite".equals(event)) {
                    return Type.UNFAVORITE;
                } else if ("follow".equals(event)) {
                    return Type.FOLLOW;
                } else if ("unfollow".equals(event)) {
                    return Type.UNFOLLOW;
                } else if (event.startsWith("list")) {
                    if ("list_member_added".equals(event)) {
                        return Type.USER_LIST_MEMBER_ADDED;
                    } else if ("list_member_removed".equals(event)) {
                        return Type.USER_LIST_MEMBER_DELETED;
                    } else if ("list_user_subscribed".equals(event)) {
                        return Type.USER_LIST_SUBSCRIBED;
                    } else if ("list_user_unsubscribed".equals(event)) {
                        return Type.USER_LIST_UNSUBSCRIBED;
                    } else if ("list_created".equals(event)) {
                        return Type.USER_LIST_CREATED;
                    } else if ("list_updated".equals(event)) {
                        return Type.USER_LIST_UPDATED;
                    } else if ("list_destroyed".equals(event)) {
                        return Type.USER_LIST_DESTROYED;
                    }
                } else if ("user_update".equals(event)) {
                    return Type.USER_UPDATE;
                } else if ("block".equals(event)) {
                    return Type.BLOCK;
                } else if ("unblock".equals(event)) {
                    return Type.UNBLOCK;
                }
            } catch (JSONException jsone) {
                try {
                    logger.warn("Failed to get event element: ", json.toString(2));
                } catch (JSONException ignore) {
                }
            }
        } else if (!json.isNull("disconnect")) {
            return Type.DISCONNECTION;
        }
        return Type.UNKNOWN;
    }
}