org.apache.streams.twitter.converter.TwitterDocumentClassifier.java Source code

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Here is the source code for org.apache.streams.twitter.converter.TwitterDocumentClassifier.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 *
 *   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 org.apache.streams.twitter.converter;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import org.apache.streams.data.DocumentClassifier;
import org.apache.streams.jackson.StreamsJacksonMapper;
import org.apache.streams.twitter.pojo.Delete;
import org.apache.streams.twitter.pojo.Follow;
import org.apache.streams.twitter.pojo.FriendList;
import org.apache.streams.twitter.pojo.Retweet;
import org.apache.streams.twitter.pojo.Tweet;
import org.apache.streams.twitter.pojo.User;
import org.apache.streams.twitter.pojo.UserstreamEvent;

import java.io.IOException;
import java.util.List;

/**
 * Ensures twitter documents can be converted to Activity
 */
public class TwitterDocumentClassifier implements DocumentClassifier {

    private static ObjectMapper mapper;

    public List<Class> detectClasses(Object document) {

        Preconditions.checkNotNull(document);
        Preconditions.checkArgument(document instanceof String || document instanceof ObjectNode);

        mapper = new StreamsJacksonMapper(Lists.newArrayList(StreamsTwitterMapper.TWITTER_FORMAT));

        ObjectNode objectNode;
        try {
            if (document instanceof String)
                objectNode = mapper.readValue((String) document, ObjectNode.class);
            else if (document instanceof ObjectNode)
                objectNode = (ObjectNode) document;
            else
                return Lists.newArrayList();
        } catch (IOException e) {
            return Lists.newArrayList();
        }

        List<Class> classList = Lists.newArrayList();

        if (objectNode.findValue("retweeted_status") != null && objectNode.get("retweeted_status") != null)
            classList.add(Retweet.class);
        else if (objectNode.findValue("delete") != null)
            classList.add(Delete.class);
        else if (objectNode.findValue("friends") != null || objectNode.findValue("friends_str") != null)
            classList.add(FriendList.class);
        else if (objectNode.findValue("target_object") != null)
            classList.add(UserstreamEvent.class);
        else if (objectNode.findValue("follower") != null && objectNode.findValue("followee") != null)
            classList.add(Follow.class);
        else if (objectNode.findValue("location") != null && objectNode.findValue("user") == null)
            classList.add(User.class);
        else
            classList.add(Tweet.class);

        return classList;
    }

}