TD6 Compression/Decompression RLE

Compression.java

package TD6;

public class Compression implements ICompression {
	
	/* encode une chaine de caractère c de longueur L de la facon suivante :
	 * cFLAGL
	 * L max = 9
	 * Si flag est rencontré on encode ça de la facon suiante : FLAG0
	 * 
	 */
	
	private char flag;
	private char currentChar;
	
	Compression(char flag) {
		this.flag = flag;
	}

	// data, chaine à compresser de type aaaaaaaa ou #aaaa
	@Override
	public String compress(String data) throws Exception {
		StringBuilder compressed_data = new StringBuilder();
		char[] array = data.toCharArray();
		
		for(int i = 0; i < array.length; i++ ) {
			this.currentChar = array[i];
			
			if ( array[i] == this.flag ) {
				compressed_data.append(this.flag + "0");
			} else {
				int compteur = 0;
				
				do {
					compteur++;
				} while ( i+compteur < array.length && array[i+compteur] == this.currentChar && compteur < 9 );
				
				if (compteur < 4) {
					for(int j = 0; j < compteur; j++ ) {
						compressed_data.append(this.currentChar);
					}
				} else {
					compressed_data.append(this.currentChar); 	
					compressed_data.append(this.flag);
					compressed_data.append(compteur);
				}
				i+=compteur-1;	
				
			}
			
		}
		
		return compressed_data.toString();
	}
	
	// prend une data de type #0a#9a#7
	@Override
	public String decompress(String data) throws Exception {
		StringBuilder decompress_data = new StringBuilder();
		char[] array = data.toCharArray();
		
		for (int i = 0; i < array.length; i++) {
			
			if (array[i] == this.flag ) {
				
				if ( array[i+1] == '0' ) {
					decompress_data.append(this.flag);
				} else 
				if ( array[i+1] <= '9' && array[i+1] > '0' ) {
					for (int j = 1; j < (int) (array[i+1] - '0'); j++) {
						decompress_data.append(array[i-1]);
					}
				} 
				else 
				{
					throw new Exception("Caractère " + array[i] + " incorecte après le flag " + array[i-1] + "\ndécodé à ce stade : " + decompress_data.toString());
				}
				i++;
				
			}else {
				decompress_data.append(array[i]);
				
			}
			
		}
		
		return decompress_data.toString();
	}



}

Compression2.java

/**
 * @author dysta
 */
package TD7;

import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

public class Compression implements ICompression {
	private char currentChar;
	private char flag;
	
	/**
	 * Create a compression/decompression methode
	 * @param flag the flag is used in your string
	 */
	public Compression(char flag) {
		this.flag = flag;
	}
	
	@Override
	public void compress(String data, Writer out) throws IOException {
		StringBuilder compressed_data = new StringBuilder();
		char[] array = data.toCharArray();
		
		for(int i = 0; i < array.length; i++ ) {
			this.currentChar = array[i];
			
			if ( array[i] == this.flag ) {
				compressed_data.append(this.flag + "0");
			} else {
				int compteur = 0;
				
				do {
					compteur++;
				} while ( i+compteur < array.length && array[i+compteur] == this.currentChar && compteur < 9 );
				
				if (compteur < 4) {
					for(int j = 0; j < compteur; j++ ) {
						compressed_data.append(this.currentChar);
					}
				} else {
					compressed_data.append(this.currentChar); 	
					compressed_data.append(this.flag);
					compressed_data.append(compteur);
				}
				i+=compteur-1;	
				
			}
			
		}
		
		out.write(compressed_data.toString());
		out.flush();
		
	}

	@Override
	public void uncompress(String data, Writer out) throws IOException {
		StringBuilder decompress_data = new StringBuilder();
		char[] array = data.toCharArray();
		
		for (int i = 0; i < array.length; i++) {
			
			if (array[i] == this.flag ) {
				
				if ( array[i+1] == '0' ) {
					decompress_data.append(this.flag);
				} else 
				if ( array[i+1] <= '9' && array[i+1] > '0' ) {
					for (int j = 1; j < (int) (array[i+1] - '0'); j++) {
						decompress_data.append(array[i-1]);
					}
				} 
				else 
				{
					decompress_data.delete(0, decompress_data.length());
					decompress_data.append("Caractère " + array[i] + " incorecte après le flag " + array[i-1] + "\ndécodé à ce stade : " + decompress_data.toString() + "\n");
				}
				i++;
				
			}else {
				decompress_data.append(array[i]);
				
			}
			
		}
		
		out.write(decompress_data.toString());
		out.flush();
	}

	@Override
	public void compress(Reader in, Writer out) throws IOException {
		StringBuilder str = new StringBuilder();
		int c;
		while ( (c = in.read() ) != -1 ) {	
			str.append((char) c);
		}
		this.compress(str.toString(), out);
	}

	@Override
	public void uncompress(Reader in, Writer out) throws IOException {
		StringBuilder str = new StringBuilder();
		int c;
		while ( (c = in.read() ) != -1 ) {	
			str.append((char) c);
		}
		this.compress(str.toString(), out);
	}

}

ICompression.java

package TD6;

public interface ICompression {
	public String compress(String data) throws Exception;
	public String decompress(String data) throws Exception;
}

ICompression2.java

package TD7;

import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

public interface ICompression {
	public void compress(String data, Writer out) throws IOException;
	public void uncompress(String data, Writer out) throws IOException;
	
	public void compress(Reader in, Writer out) throws IOException;
	public void uncompress(Reader in, Writer out) throws IOException;
}

RLE.java

package TD6;

public class RLE {

	public static void main(String[] args) {
		Compression c = new Compression('#');
		
		try {
		String a = c.decompress("a#7#0#0b##6a#8b#7c#9c#0a");
		System.out.println(a);
		} catch ( Exception e ) {
			System.out.println(e.getMessage());
		}

	}

}

RLE2.java

package TD7;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import TD7.Compression;

public class RLE {

	public static void main(String[] args) {
		Compression c = new Compression('#');
		BufferedWriter out1 = null;
		BufferedWriter out2 = null;
		BufferedWriter out3 = null;
		
		BufferedReader in = null;
		
		try {
			out1 = new BufferedWriter(new FileWriter("file.out"));
			out2 = new BufferedWriter(new FileWriter("file2.out"));
			out3 = new BufferedWriter(new FileWriter("file3.out"));
			 
			c.uncompress("a#7#0#0b#6a#8b#7c#9c#0a", out1);
			c.compress("###aaaaaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbbboooooooooocccccccccccpppaaaaa#####", out2);
			
			in = new BufferedReader(new FileReader("file.out"));
			
			c.compress(in, out3);
			
		} catch (IOException e) {
			System.out.println(e.getMessage());
		} finally {
			if ( out1 != null && out2 != null && out3 != null )
				try {
					out1.close();
					out2.close();
					out3.close();
				} catch (IOException e) {
					System.out.println(e.getMessage());
				}
		}
	}

}