CountedSet.java Source code

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Here is the source code for CountedSet.java

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///////////////////////////////////////////////////////////////////////////////
//Copyright (C) 2003 Thomas Morton
//
//This library is free software; you can redistribute it and/or
//modify it under the terms of the GNU Lesser General Public
//License as published by the Free Software Foundation; either
//version 2.1 of the License, or (at your option) any later version.
//
//This library 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 Lesser General Public License for more details.
//
//You should have received a copy of the GNU Lesser General Public
//License along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//////////////////////////////////////////////////////////////////////////////

//package opennlp.tools.util;

import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

/**
 * Set which counts the number of times a values are added to it.  
 * This value can be accessed with the #getCount method.
 */
public class CountedSet implements Set {

    private Map cset;
    private static Integer ONE = Integer.valueOf(1);

    /**
     * Creates a new counted set.
     */
    public CountedSet() {
        cset = new HashMap();
    }

    /** Creates a new counted set of the specified initial size.
     * @param size The initial size of this set.
     */
    public CountedSet(int size) {
        cset = new HashMap(size);

    }

    public boolean add(Object o) {
        Integer count = (Integer) cset.get(o);
        if (count == null) {
            cset.put(o, ONE);
            return true;
        } else {
            cset.put(o, Integer.valueOf(count.intValue() + 1));
            return false;
        }
    }

    /**
     * Reduces the count associated with this object by 1.  If this causes the count
     * to become 0, then the object is removed form the set.
     * @param o The object whose count is being reduced.
     */
    public void subtract(Object o) {
        Integer count = (Integer) cset.get(o);
        if (count != null) {
            int c = count.intValue() - 1;
            if (c == 0) {
                cset.remove(o);
            } else {
                cset.put(o, Integer.valueOf(c));
            }
        }
    }

    /**
     * Assigns the specified object the specified count in the set.
     * @param o The object to be added or updated in the set.
     * @param c The count of the specified object.
     */
    public void setCount(Object o, int c) {
        cset.put(o, Integer.valueOf(c));
    }

    /**
     * Return the count of the specified object.
     * @param o the object whose count needs to be determined.
     * @return the count of the specified object.
     */
    public int getCount(Object o) {
        Integer count = (Integer) cset.get(o);
        if (count == null) {
            return 0;
        } else {
            return count.intValue();
        }
    }

    public void write(String fileName, int countCutoff) {
        write(fileName, countCutoff, " ");
    }

    public void write(String fileName, int countCutoff, String delim) {
        write(fileName, countCutoff, delim, null);
    }

    public void write(String fileName, int countCutoff, String delim, String encoding) {
        PrintWriter out = null;
        try {
            if (encoding != null) {
                out = new PrintWriter(new OutputStreamWriter(new FileOutputStream(fileName), encoding));
            } else {
                out = new PrintWriter(new FileWriter(fileName));
            }

            for (Iterator e = cset.keySet().iterator(); e.hasNext();) {
                Object key = e.next();
                int count = this.getCount(key);
                if (count >= countCutoff) {
                    out.println(count + delim + key);
                }
            }
            out.close();
        } catch (IOException e) {
            System.err.println(e);
        }
    }

    public boolean addAll(Collection c) {
        boolean changed = false;
        for (Iterator ci = c.iterator(); ci.hasNext();) {
            changed = changed || add(ci.next());
        }
        return changed;
    }

    public void clear() {
        cset.clear();
    }

    public boolean contains(Object o) {
        return cset.keySet().contains(o);
    }

    public boolean containsAll(Collection c) {
        return cset.keySet().containsAll(c);
    }

    public boolean isEmpty() {
        return cset.isEmpty();
    }

    public Iterator iterator() {
        return cset.keySet().iterator();
    }

    public boolean remove(Object o) {
        return cset.remove(o) != null;
    }

    public boolean removeAll(Collection c) {
        boolean changed = false;
        for (Iterator ki = cset.keySet().iterator(); ki.hasNext();) {
            changed = changed || cset.remove(ki.next()) != null;
        }
        return changed;
    }

    public boolean retainAll(Collection c) {
        boolean changed = false;
        for (Iterator ki = cset.keySet().iterator(); ki.hasNext();) {
            Object key = ki.next();
            if (!c.contains(key)) {
                cset.remove(key);
                changed = true;
            }
        }
        return changed;
    }

    public int size() {
        return cset.size();
    }

    public Object[] toArray() {
        return cset.keySet().toArray();
    }

    public Object[] toArray(Object[] arg0) {
        return cset.keySet().toArray(arg0);
    }
}