com.ijuru.ijambo.dao.WordDAO.java Source code

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Here is the source code for com.ijuru.ijambo.dao.WordDAO.java

Source

/**
 * Copyright 2012 Rowan Seymour
 * 
 * This file is part of Ijambo.
 *
 * Ijambo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Ijambo is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Ijambo. If not, see <http://www.gnu.org/licenses/>.
 */

package com.ijuru.ijambo.dao;

import java.util.HashMap;
import java.util.Map;

import com.ijuru.ijambo.Word;
import com.ijuru.ijambo.Word.Difficulty;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;

/**
 * Data access for words
 */
public class WordDAO {

    private DB db;

    /**
     * Constructs new DAO
     * @param db the database
     */
    public WordDAO(DB db) {
        this.db = db;
    }

    /**
     * Gets the number of words
     * @return the number
     */
    public long getWordCount() {
        return db.getCollection("words").count();
    }

    /**
     * Gets the number of words with different difficulty levels
     * @return map of difficulty levels and counts
     */
    public Map<Difficulty, Integer> getDifficultyCounts() {
        DBCollection words = db.getCollection("words");
        Map<Difficulty, Integer> counts = new HashMap<Difficulty, Integer>();

        for (Difficulty difficulty : Difficulty.values()) {
            BasicDBObject query = new BasicDBObject();
            query.put("difficulty", difficulty.ordinal());
            counts.put(difficulty, words.find(query).count());
        }

        return counts;
    }

    /**
     * Gets a random word
     * @param difficulty the difficulty (may be null)
     * @return the word
     */
    public Word getRandomWord(Difficulty difficulty) {
        DBCollection words = db.getCollection("words");
        BasicDBObject obj;

        if (difficulty != null) {
            // Get count of words of this difficulty
            BasicDBObject query = new BasicDBObject();
            query.put("difficulty", difficulty.ordinal());
            int count = words.find(query).count();

            // Pick random one
            int randOffset = (int) (Math.random() * count);
            obj = (BasicDBObject) words.find(query).limit(-1).skip(randOffset).next();
        } else {
            int randOffset = (int) (Math.random() * words.find().count());
            obj = (BasicDBObject) words.find().limit(-1).skip(randOffset).next();
        }

        return new Word(obj.getString("word"), obj.getString("meaning"),
                Difficulty.fromInt(obj.getInt("difficulty")));
    }

    /**
     * Removes all words
     */
    public void removeAll() {
        DBCollection words = db.getCollection("words");
        words.drop();
    }

    /**
     * Saves a word
     * @param word the word
     */
    public void save(Word word) {
        DBCollection words = db.getCollection("words");

        BasicDBObject obj = new BasicDBObject();
        obj.put("word", word.getWord());
        obj.put("meaning", word.getMeaning());
        obj.put("difficulty", word.getDifficulty().ordinal());

        words.insert(obj);
    }
}