compressing a file
Hi.
I'm trying to compress a file, but no book I've got says anything about it, and I couldn't see much in the sun tutorials, etc.
Looking through the API, it seems like I should be using stuff in java.util.zip, but I don't know ehat to use, eg what is the best Zip format.
I tried this code:
FileInputStream fis = new FileInputStream( theFile );fis.read( b );
ZipOutputStream zout = new ZipOutputStream( new FileOutputStream( "newFile.zip" ) );
zout.write( b, 0, b.length );
but when I run it I get an IOException from the 'zout.write()' line. I'm guessing I'm just not using the right streams / using them in the right way.
Does anyone know anything about this, or where I can find out?
Thanks.
[794 byte] By [
ebis] at [2007-9-26 8:01:42]
Hi,
Here is an example that archives all the log files out of a specific diretory.
package com.lendersservice.arc ;
import java.util.zip.* ;
import java.io.* ;
import java.util.Date ;
import java.text.SimpleDateFormat ;
public class ArchiveLogs extends Object {
public ArchiveLogs() { }
public static void main( String args[] ) {FilenameFilter select = new FileListFilter( "", "log" );String directory = "E:\\orant\\ows\\admin\\website40\\log\\" ;
ZipOutputStream out = null ;
try{
File myDir = new File( directory ) ;
String[] contents = myDir.list( select );System.out.println( "Processing files from " + myDir.getName() );
if ( contents != null ){
//create the zip file
SimpleDateFormat df = new SimpleDateFormat( "MMddyyyy" ) ;
Date today = new Date();
String outFilename = "logsfor" + df.format( today ) + ".zip";
out = new ZipOutputStream(new FileOutputStream( outFilename ));
for ( int i = 0 ; i < contents.length ; i++ ) { System.out.println(contents[ i ]); processFile(myDir, contents[ i ], out );
}
}
out.close();
}catch ( Exception e )
{System.out.println( "Error ::" + e );}
} static void processFile( File myDir , String fileName , ZipOutputStream out )
{try
{
File f = new File( myDir, fileName );
FileInputStream in = new FileInputStream( f );
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry( fileName ));
byte[] buf = new byte[1024];
int len ;
while ( ( len = in.read( buf ) ) > 0) {
out.write( buf , 0 , len );}
out.closeEntry();
in.close();
f.delete();
}catch ( Exception e )
{System.out.println( "Error ::" + e );}
}
}
package com.lendersservice.arc ;
import java.io.* ;
import java.util.Date ;
public class FileListFilter implements FilenameFilter{private String name ;
private String extention ;
//constrictor public FileListFilter( String name , String extention ) {
this.name = name.toLowerCase();
this.extention = extention.toLowerCase(); }
public boolean accept( File directory , String filename ) {boolean fileOK = true ;
filename = filename.toLowerCase();
//If there is a name filter specified, check the file nameif ( name.length() != 0 )
fileOK &= filename.startsWith( name );
//If there is an extention specified check the the extention
if ( extention != null )
fileOK &= filename.endsWith( '.' + extention );return fileOK ; }
}
Hope this will help you.
Anil.
Developer Technical Support
Sun Microsystems Inc,
http://www.sun.com/developers/support
