// GZIPFile

import java.io.*;
import java.util.zip.*;

/**                 ..... class GzipFile .....         
*  Reads the contents of the GZIP file and 
*  Writes data in GZIP file format 
*
*  Constructor
*        public GzipFile(String fileName);
*  Methods
*        public void write(byte[] b);
*        public byte[] read();
*
*  @author Jeff Zhuk
**/  

public class GzipFile {
    private String fileName;
    private FileOutputStream out;
    private GZIPOutputStream go;      
    private FileInputStream in;
    private GZIPInputStream goin;      

/*  Gzip(String iName) constructor is to store a name
 *  in - gzip file name Ex. Gzip gzip = new Gzip("myfile.zip");  
 *
 */
     public Gzip (String iName){           
         fileName = iName;
     }

/* writing array of bytes into a compressed file
 * @param b array of bytes to write
 */
     public void write(byte[] b) {

         try{
               out = new FileOutputStream(fileName);
               go = new GZIPOutputStream(out);      
               System.out.println("length b.length "+ b.length);

               go.write(b, 0, b.length);
               go.close();
               out.close();
           } catch (IOException ioe) {
               System.out.println("Gzip: " + ioe);
           }
     }

/*   
 * reading a compressed file to be decompressed 
 * into an initial array of bytes
 * @return bb decompressed array of bytes
 */
     public byte[] read() {

         byte[] bb = null;                
         int byteread = 0;
         int count = 1;
         int NumberByteInArray = 0;   

         try{
             in=new FileInputStream(fileName);
             goin = new GZIPInputStream(in);      
     
             while(count != -1) {
                 byte[] ab = new byte[1];
                 count = goin.read(ab, count - 1, count);
             if(count == 1)
                 NumberByteInArray++;
             }
                 in.close();
         } catch (IOException ioe) {
             System.out.println("Gzip: " + ioe);
         }

         try{
             in=new FileInputStream(fileName);
             goin = new GZIPInputStream(in);      
             bb = new byte[NumberByteInArray];               

             while(byteread != -1) {
                 byteread = goin.read(bb, 0, NumberByteInArray);       
             }

             in.close();
         } catch (IOException ioe) {
             System.out.println("Gzip: " + ioe);
         }
         return bb;
     }

/*  main(String args[])
 * test method 
 * It writes a string of text into a compressed file
 * Then it reads the compressed file and restore the string
 */
     public static void main(String args[]){
         String str ="Test .... Test";
         byte[] b = new byte[str.length()];
           
          //String To Byte
          str.getBytes(0,str.length(),b,0);

          GzipFile nn = new GzipFile("itschool.zip");
          nn.write(b);
          byte[] out = nn.read();
          String s = new String(out);
          System.out.println("reading compressed bytes:" + s);
    }//end main
} // End Class

Back to I/O Classes Overview