Java tutorial
//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 and assigns them a unique positive index. * These value can be accessed with the #getCount() or #getIndex() method. */ public class CountedNumberedSet extends NumberedSet { private Map cset; private int max; /** * Creates a new counted set. */ public CountedNumberedSet() { cset = new HashMap(); max = 1; } /** Creates a new counted set of the specified initial size. * @param size The initial size of this set. */ public CountedNumberedSet(int size) { cset = new HashMap(size); max = 1; } public boolean add(Object o) { int[] nums = (int[]) cset.get(o); if (nums == null) { cset.put(o, new int[] { 1, max++ }); return true; } else { nums[0]++; 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) { int[] count = (int[]) cset.get(o); if (count != null) { count[0]--; if (count[0] <= 0) { cset.remove(o); } } } /** * 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) { int[] nums = (int[]) cset.get(o); if (nums != null) { nums[0] = c; } else { cset.put(o, new int[] { c, 1 }); } } /** * 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) { int[] nums = (int[]) cset.get(o); if (nums == null) { return 0; } else { return nums[0]; } } /** * Returns the index for the specified key or -1 if specified value is not contain in this set. * @param key The key to be checked. * @return the index for the specified value or -1 if specified value is not contain in this set */ public int getIndex(Object key) { int[] nums = (int[]) cset.get(key); if (nums == null) { return -1; } else { return nums[1]; } } 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); } } class NumberedSet implements Set { private int max; private Map nset; public NumberedSet() { super(); nset = new HashMap(); max = 1; } public NumberedSet(int size) { super(); nset = new HashMap(size); max = 1; } /** * Returns the index for the specified key or -1 if specified value is not contain in this set. * @param key The key to be checked. * @return the index for the specified value or -1 if specified value is not contain in this set */ public int getIndex(Object key) { Integer i = (Integer) nset.get(key); if (i == null) { return -1; } else { return i.intValue(); } } public void setIndex(Object key, int index) { nset.put(key, Integer.valueOf(index)); } public int size() { return nset.size(); } public boolean isEmpty() { return nset.isEmpty(); } public boolean contains(Object o) { return nset.containsKey(o); } public Iterator iterator() { return nset.keySet().iterator(); } public Object[] toArray() { return nset.keySet().toArray(); } public Object[] toArray(Object[] arg0) { return nset.keySet().toArray(arg0); } public boolean add(Object arg0) { if (!nset.containsKey(arg0)) { nset.put(arg0, Integer.valueOf(max++)); return true; } return false; } public boolean remove(Object o) { return nset.remove(o) != null; } public boolean containsAll(Collection c) { return nset.keySet().containsAll(c); } public boolean addAll(Collection c) { boolean changed = false; for (Iterator ci = c.iterator(); ci.hasNext();) { changed = changed || add(ci.next()); } return changed; } public boolean retainAll(Collection c) { boolean changed = false; for (Iterator ki = nset.keySet().iterator(); ki.hasNext();) { Object key = ki.next(); if (!c.contains(key)) { nset.remove(key); changed = true; } } return changed; } public boolean removeAll(Collection c) { boolean changed = false; for (Iterator ki = nset.keySet().iterator(); ki.hasNext();) { changed = changed || nset.remove(ki.next()) != null; } return changed; } public void clear() { nset.clear(); } }