Hi I am working on a project on writing our own huffman coding. I am currently having trouble writing the binary 1's and 0's to an output file. It works with smaller input files but for very large files it does not write anything out to the output file. The method responsible for writing is the compress method. Any help would be appreciated. Thank you!
package proj3;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.PriorityQueue;
public class Project3 {
//variables for PriorityQueue and Huffman Tree
private static PriorityQueue<BinaryNode<Character>> queue;
private static BinaryNode<Character> huffTree;
private static Map<Character, String> table = new LinkedHashMap<Character, String>();
/**
* Method for creating Huffman Tree
* @param counts Map that contains all characters and their frequencies
* @return the Huffman Tree
*/
public static BinaryNode<Character> makeTree(Map<Character, Integer> counts)
{
queue = new PriorityQueue<BinaryNode<Character>>();
for(Character c : counts.keySet())
{
BinaryNode<Character> tree = new BinaryNode<Character>(c, counts.get(c), null, null);
queue.add(tree);
}
while(!queue.isEmpty())
{
if(queue.size() >= 2)
{
BinaryNode<Character> n1 = queue.remove();
BinaryNode<Character> n2 = queue.remove();
Integer weight = n1.getFreq() + n2.getFreq();
huffTree = new BinaryNode<Character>(null, weight, n1, n2);
queue.add(huffTree);
}
if(queue.size() == 1)
{
return queue.remove();
}
}
return huffTree;
}
public static void encode(BinaryNode<Character> node, String s)
{
if(!node.isLeaf())
{
encode(node.getLeft(), s + "0");
encode(node.getRight(), s + "1");
}
else
{
table.put(node.getElement(), s);
}
}
public static void compress(String in, String out) throws IOException
{
try
{
File outFile = new File(out);
FileOutputStream compressedFile = new FileOutputStream(outFile);
Scanner infile = new Scanner(new FileInputStream(in));
while(infile.hasNext())
{
infile.useDelimiter("");
String str = infile.next();
Character ch = str.charAt(0);
compressedFile.write(table.get(ch).getBytes());
}
compressedFile.write(table.get('^').getBytes());
infile.close();
compressedFile.flush();
compressedFile.close();
}
catch (FileNotFoundException e)
{
System.err.println("File not found.");
e.printStackTrace();
}
}
public static void decompress(String s)
{
}
public static void printEncodings(Map<Character, String> m)
{
ArrayList<Character> chars = new ArrayList<Character>();
System.out.println("Character Encodings");
System.out.println("---------------------");
for(Character c : m.keySet())
{
chars.add(c);
Collections.sort(chars);
}
for(Character c : chars)
{
if((int) c == 10)
{
System.out.print("Newline" + "\t" + table.get(c));
}
else
{
System.out.println(c + "\t" + table.get(c));
}
}
System.out.println();
System.out.println("Total Characters: " + chars.size());
}
/**
* Method for creating map with character and its frequencies
* @param s the file name to be opened
* @return the Map containing characters and frequencies
*/
public static Map<Character, Integer> charCount(String s){
Map<Character, Integer> counts = new LinkedHashMap<Character, Integer>();
ArrayList<Character> chars = new ArrayList<Character>();
try {
Scanner file = new Scanner(new FileInputStream(s));
while(file.hasNext()){
file.useDelimiter("");
String str = file.next();
Character c = str.charAt(0);
if(counts.containsKey(c)){
counts.put(c, counts.get(c) + 1);
}
else{
counts.put(c, 1);
}
}
counts.put('^', 1);
System.out.println("Character Frequencies");
System.out.println("---------------------");
for(Character c : counts.keySet())
{
chars.add(c);
Collections.sort(chars);
}
for(Character c : chars)
{
if((int) c == 10)
{
System.out.print("Newline" + "\t" + counts.get(c));
}
else
{
System.out.println(c + "\t" + counts.get(c));
}
}
System.out.println();
System.out.println("Total characters: " + chars.size() + "\n");
file.close();
}
catch (FileNotFoundException e) {
System.err.println("File not found.");
System.exit(0);
}
return counts;
}
public static void main(String[] args){
if(args.length != 3)
{
throw new IllegalArgumentException("Invalid number of arguments.");
}
encode(makeTree(charCount(args[0])), "");
printEncodings(table);
try {
compress(args[0], args[1]);
} catch (IOException e) {
e.printStackTrace();
}
}
}
