Name: paC48320 Date: 09/15/97


Using a ZipInputStream on a JAR(ZIP) file, the
ZipEntry data retrieved via getNextEntry doesn't
have the CRC, Size or Compressed size fields propagated
properly using DEFLATED mode. The reason for this is in
examining ZipOutputStream source, the LOCEXT header is being
written at the end of the data, however the ZipInputStream isn't
accessing the information. Thus, if you're scanning through
a JAR file, the only way to objtain the size, csize and crc
for a ZipEntry is to look at the CEN info, via ZipFile.entries().

This is definitely a bug, You should be able to traverse
a Zip file and get the size info propageted into the ZipEntries
properly. The following code demonstrates the problem...

// zipbug demonstrates bug in Zip code

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

public class zipbug
{
   static File zipFile_ = new File("zipbug.zip");
static int theSize_ = 0;

   static void writeEntries(int count) throws Exception
   {
FileOutputStream fo = new FileOutputStream(zipFile_);
ZipOutputStream out = new ZipOutputStream(fo);
ZipEntry entry;

String string = new String("This is only a test...");
byte [] bytes = string.getBytes();
theSize_ = bytes.length;
System.out.println("String is " + string + " length = " + theSize_);
for(int i = 0;i < count;i++)
{
           entry = new ZipEntry(new String("Testing " + i));
entry.setMethod(ZipEntry.DEFLATED);
entry.setSize(theSize_);

out.putNextEntry(entry);
out.write(bytes,0,theSize_);
}
out.close();
fo.close();
   }

   static void getEntries() throws Exception
   {
System.out.println("Scanning via Central Info and ZipFile..\n");
ZipFile zip = new ZipFile(zipFile_);
Enumeration entries = zip.entries();
ZipEntry entry;
while(entries.hasMoreElements())
{
entry = (ZipEntry)entries.nextElement();
System.out.print("Entry Named " + entry.getName() + " Size=" + entry.getSize());
if(entry.getSize() != theSize_)
System.out.println(" [Failed]");
else
System.out.println(" [OK]");

}
zip.close();
   }

   static void scanEntries() throws Exception
   {
System.out.println("Scanning via LOC Info and ZipInputStream..\n");
FileInputStream fi = new FileInputStream(zipFile_);
ZipInputStream in = new ZipInputStream(fi);
ZipEntry entry;
while(true)
{
entry = in.getNextEntry();
if(entry == null)
break;
System.out.print("Entry Named " + entry.getName() + " Size=" + entry.getSize());
if(entry.getSize() != theSize_)
System.out.println(" [Failed]");
else
System.out.println(" [OK]");
}
in.close();
fi.close();
}

   static public void main(String args[])
   {
       try
       {
writeEntries(10);
getEntries();
scanEntries();
       } catch (Exception e)
       {
System.out.println(e.toString());
       }
   }


}

company - Park City Group , email - ###@###.###
======================================================================