ait.ffma.utils.KeyAndFrequency.java Source code

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Here is the source code for ait.ffma.utils.KeyAndFrequency.java

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/**
 *  Copyright 2012 Diego Ceccarelli
 *
 *  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 ait.ffma.utils;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Date;
import java.util.List;

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

/**
 * KeyAndFrequency.java
 * 
 * @author Diego Ceccarelli, diego.ceccarelli@isti.cnr.it created on 27/mar/2012
 */
public class KeyAndFrequency<K> {
    private K key;
    private int freq;
    private static final String KEY_FLD = "key";
    private static final String FREQ_FLD = "frequency";
    private static DateFormat format = new SimpleDateFormat("yyyyMMdd");

    public KeyAndFrequency(K key, int freq) {
        this.key = key;
        this.freq = freq;
    }

    public KeyAndFrequency(K key) {
        this.key = key;
    }

    public void add(int value) {
        freq += value;
    }

    public K getKey() {
        return key;
    }

    public void setKey(K key) {
        this.key = key;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((key == null) ? 0 : key.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        KeyAndFrequency other = (KeyAndFrequency) obj;
        if (key == null) {
            if (other.key != null)
                return false;
        } else if (!key.equals(other.key))
            return false;
        return true;
    }

    public int getFreq() {
        return freq;
    }

    public void setFreq(int freq) {
        this.freq = freq;
    }

    public JSONObject toJson() {
        JSONObject json = new JSONObject();
        try {
            if (key instanceof Date) {
                json.put(KEY_FLD, format.format((Date) key));

            } else {
                json.put(KEY_FLD, key.toString());
            }
            json.put(FREQ_FLD, getFreq());
        } catch (JSONException e) {
            return null;
        }
        return json;
    }

    public static KeyAndFrequency fromJson(JSONObject obj, Class clazz) {
        try {
            if (clazz.equals(Integer.class)) {
                KeyAndFrequency kf = new KeyAndFrequency(obj.getInt(KEY_FLD), obj.getInt(FREQ_FLD));
                return kf;
            }
            if (clazz.equals(String.class)) {
                KeyAndFrequency kf = new KeyAndFrequency(obj.get(KEY_FLD), obj.getInt(FREQ_FLD));
                return kf;
            }

            if (clazz.equals(Date.class)) {
                KeyAndFrequency kf = null;
                try {

                    kf = new KeyAndFrequency(format.parse(obj.getString(KEY_FLD)), obj.getInt(FREQ_FLD));
                } catch (ParseException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                return kf;
            }
        } catch (JSONException e) {

        }
        return null;
    }

    public static KeyAndFrequency fromJson(JSONObject obj) {
        return fromJson(obj, String.class);
    }

    public static JSONArray listToJson(List<KeyAndFrequency> list) {
        JSONArray array = new JSONArray();
        for (KeyAndFrequency k : list) {
            array.put(k.toJson());
        }
        return array;
    }

    public static List<KeyAndFrequency> listFromJson(String json) {
        return listFromJson(json, String.class);
    }

    public static List<KeyAndFrequency> listFromJson(String json, Class clazz) {
        List<KeyAndFrequency> list = new ArrayList<KeyAndFrequency>();
        JSONArray array;
        try {
            array = new JSONArray(json);
        } catch (JSONException e1) {
            return list;
        }
        for (int i = 0; i < array.length(); i++) {
            JSONObject jo;
            try {
                jo = array.getJSONObject(i);
                list.add(fromJson(jo, clazz));
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
        return list;
    }

    @Override
    public String toString() {
        return "KeyAndFreq [key=" + key + ", freq=" + freq + "]";
    }

    public static class CompareByKey implements Comparator<KeyAndFrequency> {

        @Override
        public int compare(KeyAndFrequency arg0, KeyAndFrequency arg1) {
            if (arg0.getKey() instanceof Comparable && arg1.getKey() instanceof Comparable) {
                Comparable l = (Comparable) arg0.getKey();
                Comparable r = (Comparable) arg1.getKey();
                return l.compareTo(r);
            }
            return 0;
        }

    }

    public static class CompareByValue implements Comparator<KeyAndFrequency> {

        @Override
        public int compare(KeyAndFrequency arg0, KeyAndFrequency arg1) {
            return arg0.getFreq() - arg1.getFreq();
        }

    }

}