readin.java

Huffman Algorithm: 基础的压缩方式

package huffman_tree;

import java.io.IOException;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.util.Vector;

public class ReadIn {
	public static int fileSize = 0;

	public static Vector<HuffmanNode> readIn(String fileName) {
		String line;
		StringBuilder result = new StringBuilder();
		// fileName = "Test.txt";
		// File file = new File("Test.txt");
		// System.out.println(file.length());
		try {
			BufferedReader buff = new BufferedReader(new InputStreamReader(
					new FileInputStream(fileName)));
			while ((line = buff.readLine()) != null) {
				result.append(line);
			}
			buff.close();
		} catch (FileNotFoundException ex) {
			ex.printStackTrace();
		} catch (IndexOutOfBoundsException ex) {
			ex.printStackTrace();
		} catch (IOException ex) {
			ex.printStackTrace();
		}
		Vector<Character> word = new Vector<Character>();
		for (int i = 0; i < result.length(); i++) {
			if (!word.contains(result.charAt(i))) {
				word.add(result.charAt(i));
			}
		}
		Object[] letterArray = new Object[word.size()];
		int[] freqArray = new int[word.size()];
		Vector<HuffmanNode> letterNode = new Vector<HuffmanNode>();
		if (!word.isEmpty()) {
			letterArray = word.toArray();
			for (int i = 0; i < result.length(); i++) {
				for (int j = 0; j < letterArray.length; j++) {
					if (result.charAt(i) == (char) (Character) letterArray[j]) {
						freqArray[j]++;
					}
				}
			}
			for (int j = 0; j < letterArray.length; j++) {
				letterNode.add(new HuffmanNode(
						(char) (Character) letterArray[j], freqArray[j]));
				// System.out.println((char) (Character) letterArray[j] + ""
				// + freqArray[j]);
			}

		}
		fileSize = result.length();
		return letterNode;
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ReadIn.readIn("Test.txt");
		System.out.println(HuffmanNode.nodeNum);
	}
}