Java Error While appending to Zip File

[Sasanka Boxi]

Hello Experts,

I am constantly getting the bellow error:
Could not rename zip file

Please help.

Here goes my code.

int BUFFER_SIZE = 256;

// Create datebased timestamp for unique file names
Format formatter;
formatter = new SimpleDateFormat("yyyyMMdd_HHmmssS"); //Format as YearMonthDay_HourMinuteSecMillisec
Date now = new Date();
String datestring = formatter.format(now);
	
String oldZipfilename = zipfilename + datestring + ".old";
String newZipfilename = zipfilename + datestring + ".new";
File newZipfile = new File(newZipfilename);
File zipfile = new File(zipfilename);

ZipFile oldzip = null;
File oldZipfile = null;
ZipOutputStream zos = null;


try {
  zos = new ZipOutputStream(new FileOutputStream(newZipfile));
  
  if(zipfile.exists()) {
      // Copy old entries
      oldZipfile = new File(oldZipfilename);
	
	boolean success = zipfile.renameTo(oldZipfile);
	if (!success) {
		throw new ServiceException("Could not rename zip file from " + zipfile + " to " + oldZipfile);
	}
      
      	oldzip = new ZipFile(oldZipfile);
      
      	for (Enumeration entries = oldzip.entries(); entries.hasMoreElements();) {
          	ZipEntry entry = (ZipEntry) entries.nextElement();
          	String entryFilename = entry.getName();
		if (!entryFilename.equals(filename)) {
			BufferedInputStream is = new BufferedInputStream(oldzip.getInputStream(entry));
			zos.putNextEntry(new ZipEntry(entry));
          		byte buffer[] = new byte[BUFFER_SIZE];
          		int count;
          			while ((count = is.read(buffer, 0, BUFFER_SIZE)) != -1) {
            			zos.write(buffer, 0, count);
          			}
         	 	zos.flush();
         	 	zos.closeEntry();
			is.close();
		}
			
         	
     	 }
      
  }
  
  // Add new entry
  zos.putNextEntry(new ZipEntry(filename));
  zos.write(ffdata);
  zos.closeEntry();
  zos.close();
  if (oldzip != null) {
    oldzip.close();
  }
  if (oldZipfile != null) {
    oldZipfile.delete();
  }
  // Remove ".new"
  boolean success = newZipfile.renameTo(zipfile);
  if (!success) {
    throw new ServiceException("Could not rename zip file from " + newZipfile + " to " + zipfile);
  }
}
catch (IOException e) {
  ServerAPI.logError(e);
  throw new ServiceException("appendToZipFile" + " error occured while appending to zip file: " + zipfilename + " ::: " + e.getMessage());    
}
finally {
  try {
    if (zos != null) {
      zos.close();
    }

    if (oldzip != null) {
      oldzip.close();
    }
  }
  catch (IOException e) {
    ServerAPI.logError(e);
  }
}

[Rob Spoor]

You still have an OutputStream to the file open. That means that Windows disallows renaming, deleting, etc. You can't delete or rename a file in Java unless all streams etc to it are closed. Also, the file to rename to cannot exist yet.

[Sasanka Boxi]

I have updated the code now...could you please verify once...

[Wouter Oet]

if zos.close(); throwns an exception then oldzip isn't closed.

[Sasanka Boxi]

Recently we updated the JVM version, is this an issue with JVM