binthread.java

Huffman编码的java实现。含实验报告。

package gilyou;


import java.io.BufferedWriter;
import java.io.EOFException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.RandomAccessFile;

public class BinThread extends Thread {
	private File file = null;
	private HuffmanNode[] symbols;
	public BinThread(String fileName,HuffmanNode[] symbols){
		this.file = new File(fileName);
		this.symbols = symbols;
	}
	public void run(){
		try {
			doBin();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private void doBin() throws IOException{
		Main.binCheckBox.setEnabled(false);
		RandomAccessFile binReader = null;
		BufferedWriter binWriter = null;
		byte firstSymbol;
		byte nextSymbol;
		int symbolLen = 0;
		int label = 1;
		label <<= 31;
		int buffer = 0;
		int size = 0;
		HuffmanNode pointer;		
		binReader = new RandomAccessFile(file.getPath(),"r");
		binWriter = new BufferedWriter(new FileWriter(new File(file.getPath() + ".bin"),true));
		for (firstSymbol = binReader.readByte(); firstSymbol != -1; firstSymbol = nextSymbol ) {
			for (symbolLen = 1, nextSymbol = (byte)binReader.read(); nextSymbol != -1 && nextSymbol == firstSymbol; symbolLen++)
				nextSymbol = binReader.readByte();
			for (pointer = symbols[firstSymbol+128]; pointer != null && symbolLen != pointer.symbolLen; pointer = pointer.right);
			size = pointer.codeWordLen;
			buffer = pointer.codeWord;
			int i;
			for( i = 0; i < 32 - size; i++);
			buffer <<= i;
			for(int j = 0; j < size; j++){
				if((buffer & label) == 0)
					binWriter.write("0");
				else 
					binWriter.write("1");
				buffer <<= 1;
			}
		}

		Main.binCheckBox.setEnabled(true);
		binReader.close();
		binWriter.close();
		this.interrupt();
	}


}