How to zip text files ?

Question

Hello to everybody,
My problems is to compress text files into a .zip file, I have used the following method:
public void zippa() {
FileReader fileIn;
BufferedReader in;
String riga;
boolean eof = false;
ZipEntry zEntry;
try {
FileOutputStream fout = new FileOutputStream("C:\\Davide\\zip\\W4.zip");
fileIn = new FileReader("C:\\Davide\\zip\\W4.txt");
in = new BufferedReader(fileIn);
riga = in.readLine();
FileWriter fileOut = null;
BufferedWriter out = null;
CheckedOutputStream csum = new CheckedOutputStream(fout, new Adler32());
ZipOutputStream z = new ZipOutputStream(new BufferedOutputStream(csum));
zEntry = new ZipEntry("C:\\Davide\\zip\\Sonia.txt");
z.putNextEntry(new ZipEntry(zEntry));
fileIn = new FileReader("C:\\Davide\\zip\\W4.txt");
in = new BufferedReader(fileIn);
riga = in.readLine();
System.out.println("Zipping....");
while (!eof) {
riga = in.readLine();
     if (riga != null) {
z.write(riga.getBytes(),0,riga.length());
} else eof = true;
System.out.println("Zipped....");
z.close();
fileIn.close();
} catch (IOException ioe) {
System.out.println("Eccezione: "+ioe);
ioe.printStackTrace();
My problem consist in the fact that the different lines which are coming from W4.txt, are not separeted (in the zip entry "Sonia.txt") by a carriage return (new line) character but by an unprintable character (which looks like a square).... I've tried to add a "\n" string to the String variable riga, or to add the following lines:
z.write((char)13);
z.write((char)12);
immediately after the
z.write(riga.getBytes(),0,riga.length());
instruction, but these solutions does not work.
Is someone so kind to help me please ?
Vacca Davide
[email protected]

Answer 1

The readLine() method removes new line characters as it returns one line of data at a time. When creating a zip file you want to retain all the characters in the input file. Below is the code I used to test the creation and reading of a zip file. Hope it helps.
import java.io.*;
import java.util.zip.*;
public class TestZip
public static void main(String[] args) throws IOException
zip( args[0] );
System.exit(0);
static private void zip(String fileName) throws IOException
          // Write Zip file
byte[] iobuff = new byte[512];
int bytes;
FileInputStream fis = new FileInputStream( fileName );
ZipOutputStream zos = new ZipOutputStream( new FileOutputStream( fileName + ".ZIP" ) );
ZipEntry ze = new ZipEntry( fileName );
zos.putNextEntry( ze );
while ( (bytes = fis.read( iobuff )) != -1 )
zos.write( iobuff, 0, bytes );
fis.close();
zos.close();
          // Read Zip file and rewrite to verify contents are the same
ZipInputStream zis = new ZipInputStream( new FileInputStream( fileName + ".ZIP" ) );
zis.getNextEntry();
FileOutputStream fos = new FileOutputStream (fileName + ".UNZIP" );
while ( (bytes = zis.read( iobuff, 0, 512 )) != -1 )
fos.write( iobuff, 0, bytes );
fos.close();
zis.close();