zip - Java SE 6 - Trouble recognizing directories with ZipEntry -

i've problem unzipping files directory written without "/" @ end of name.

the code works fine if file content is:

basedir/ basedir/file1.txt basedir/file2.txt 

when central directory doesn't contain "/" @ end of name, got error. in case content of zip file is:

basedir basedir/file1.txt basedir/file2.txt 

here code used unzip file

public static void unzip(final string zipfilename, final string unzipdir)         throws zipexception {      zipfile zipfile = null;     try {         final file directory = new file(unzipdir);         // check if directory extract exists         if(!directory.exists()) {             // if not, create new one.             new file(unzipdir).mkdir();         }          final file checkfile = new file(zipfilename);         if (checkfile.length() == 0) {             throw new ioexception("empty file");         }         zipfile = new zipfile(zipfilename);         enumeration<?> e = zipfile.entries();         while(e.hasmoreelements()) {             final zipentry entry = (zipentry)e.nextelement();             final file destinationfile = new file(unzipdir,entry.getname());              //create directories if required.             destinationfile.getparentfile().mkdirs();              //if entry directory, leave it. otherwise extract it.             if(entry.isdirectory()) {                 continue;             }             else {                 // inputstream current entry of zip file using                 inputstream = zipfile.getinputstream(entry);                 fileoutputstream fos = new fileoutputstream(destinationfile);                 writefile(is, fos);             }         }     }     catch(exception ex) {         throw new zipexception("error", ex);     }     {         if(zipfile!=null) {             try {                 zipfile.close();             }             catch(exception ex) {                 throw new zipexception("error", ex);             }         }     } } 

i found problem zipentry.isdirectory() method works if name of entry in zip ends "/" ( http://docs.oracle.com/javase/6/docs/api/java/util/zip/zipentry.html#isdirectory%28%29 ), doesn't work in second scenario. i'm not able find fix beaviour. how can check if entry directory without using isdirectory method? (please note can not use third party library)