com.chalmers.feedlr.parser.TwitterJSONParser.java Source code

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Here is the source code for com.chalmers.feedlr.parser.TwitterJSONParser.java

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/*
 * Copyright 2012 Feedlr
 *
 * 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.chalmers.feedlr.parser;

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

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.chalmers.feedlr.model.TwitterItem;
import com.chalmers.feedlr.model.User;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectReader;

import android.util.Log;

/**
 * Class description
 * 
 * @author Olle Werme
 */

public class TwitterJSONParser {

    private static ObjectMapper mapper;
    private static ObjectReader tweetReader;
    private static ObjectReader usernameReader;

    private static JsonFactory jfactory;
    private static JsonParser jParser;

    public TwitterJSONParser() {
        if (mapper == null) {
            mapper = new ObjectMapper();
            mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        }
    }

    public List<TwitterItem> parseTweets(String json) {
        long time = System.currentTimeMillis();

        if (tweetReader == null) {
            tweetReader = mapper.reader(new TypeReference<List<TwitterItem>>() {
            });
        }

        List<TwitterItem> list = null;

        try {
            list = tweetReader.readValue(json);
        } catch (JsonParseException e) {
            Log.e(getClass().getName(), e.getMessage());
        } catch (JsonMappingException e) {
            Log.e(getClass().getName(), e.getMessage());
        } catch (IOException e) {
            Log.e(getClass().getName(), e.getMessage());
        }

        Log.i(TwitterJSONParser.class.getName(), "Data binding parse");
        Log.i(TwitterJSONParser.class.getName(), "Items: " + list.size());
        Log.i(TwitterJSONParser.class.getName(), "Time in millis: " + (System.currentTimeMillis() - time));

        return list;
    }

    /**
     * Parse a JSON response for a list of "tweets" from Twitter's REST API with
     * Jackson's streaming parse method. Although this is a sligthly faster
     * alternative the current build uses the databinding parse, favoring a
     * simplier implementation. This method is thus currently not in use.
     * 
     * @param json
     *            the JSON response from Twitters RESP API
     */
    private List<TwitterItem> streamingTwitterParse(String json) {
        long time = System.currentTimeMillis();

        List<TwitterItem> list = new ArrayList<TwitterItem>();

        try {

            if (jfactory == null) {
                jfactory = new JsonFactory();
            }

            jParser = jfactory.createJsonParser(json);

            TwitterItem o = null;
            while (jParser.nextToken() != null) {
                if ("created_at".equals(jParser.getCurrentName())) {
                    jParser.nextToken();
                    o = new TwitterItem();
                    o.setTimestamp(jParser.getText());
                }
                if ("text".equals(jParser.getCurrentName())) {
                    jParser.nextToken();
                    o.setText(jParser.getText());
                }
                if ("name".equals(jParser.getCurrentName())) {
                    jParser.nextToken();
                    o.getUser().setUserName(jParser.getText());
                }
                if ("profile_image_url".equals(jParser.getCurrentName())) {
                    jParser.nextToken();
                    o.getUser().setProfileImageURL(jParser.getText());
                    list.add(o);
                }
            }
            jParser.close();

        } catch (JsonGenerationException e) {
            Log.e(getClass().getName(), e.getMessage());
        } catch (JsonMappingException e) {
            Log.e(getClass().getName(), e.getMessage());
        } catch (IOException e) {
            Log.e(getClass().getName(), e.getMessage());
        }

        Log.i(TwitterJSONParser.class.getName(), "Streaming parse");
        Log.i(TwitterJSONParser.class.getName(), "Items: " + list.size());
        Log.i(TwitterJSONParser.class.getName(), "Time in millis: " + (System.currentTimeMillis() - time));

        return list;
    }

    public String[] parseUserIDs(String json) {
        long time = System.currentTimeMillis();

        JSONObject wrapperObject;
        String[] ids = null;
        try {
            wrapperObject = new JSONObject(json);
            JSONArray jsonIDs = wrapperObject.getJSONArray("ids");
            ids = new String[jsonIDs.length()];
            for (int i = 0; i < jsonIDs.length(); i++) {
                ids[i] = jsonIDs.getString(i);
            }
        } catch (JSONException e) {
            Log.e(getClass().getName(), e.getMessage());
        }

        Log.i(TwitterJSONParser.class.getName(), "Parsed " + ids.length + " user ids.");
        Log.i(TwitterJSONParser.class.getName(), "Time in millis: " + (System.currentTimeMillis() - time));

        return ids;
    }

    /*
     * Parse a JSON response for a list of usernames from Twitter's REST API
     * with Jackson's databinding method.
     * 
     * @return list containing <code>Users</code>
     */
    public List<User> parseUserNames(String json) {
        long time = System.currentTimeMillis();

        if (usernameReader == null) {
            usernameReader = mapper.reader(new TypeReference<List<User>>() {
            });
        }

        List<User> list = null;

        try {
            list = usernameReader.readValue(json);
        } catch (JsonParseException e) {
            Log.e(getClass().getName(), e.getMessage());
        } catch (JsonMappingException e) {
            Log.e(getClass().getName(), e.getMessage());
        } catch (IOException e) {
            Log.e(getClass().getName(), e.getMessage());
        }

        Log.i(TwitterJSONParser.class.getName(), "Parsed " + list.size() + " users.");
        Log.i(TwitterJSONParser.class.getName(), "Time in millis: " + (System.currentTimeMillis() - time));

        return list;
    }

    public long parseCredentials(String json) {
        long time = System.currentTimeMillis();

        JSONObject wrapperObject;
        long userID = 0;
        try {
            wrapperObject = new JSONObject(json);
            userID = wrapperObject.getLong("id");
        } catch (JSONException e) {
            Log.e(getClass().getName(), e.getMessage());
        }

        Log.i(TwitterJSONParser.class.getName(), "Parsed user credentials");
        Log.i(TwitterJSONParser.class.getName(), "User ID: " + userID);
        Log.i(TwitterJSONParser.class.getName(), "Time in millis: " + (System.currentTimeMillis() - time));

        return userID;
    }
}