ZipOutputStream Question

Ant is correct, it's not supported by the Zip classes.

Found the following for adding an entry to a jar file which should be straight forward to modify to work on zip file (JarFile is simply a subclass of ZipFIle).

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

public class JarUpdate {
   /**
    * main()
    */
   public static void main(String[] args) throws IOException {
      // Get the jar name and entry name from the command-line.

      String jarName = args[0];
      String fileName = args[1];

      // Create file descriptors for the jar and a temp jar.
     
      File jarFile = new File(jarName);
      File tempJarFile = new File(jarName + ".tmp");

      // Open the jar file.

      JarFile jar = new JarFile(jarFile);
      System.out.println(jarName + " opened.");

      // Initialize a flag that will indicate that the jar was updated.

      boolean jarUpdated = false;

      try {
         // Create a temp jar file with no manifest. (The manifest will
         // be copied when the entries are copied.)

         Manifest jarManifest = jar.getManifest();
         JarOutputStream tempJar =
            new JarOutputStream(new FileOutputStream(tempJarFile));

         // Allocate a buffer for reading entry data.

         byte[] buffer = new byte[1024];
         int bytesRead;

         try {
            // Open the given file.
           
            FileInputStream file = new FileInputStream(fileName);

            try {
               // Create a jar entry and add it to the temp jar.
           
               JarEntry entry = new JarEntry(fileName);
               tempJar.putNextEntry(entry);

               // Read the file and write it to the jar.

               while ((bytesRead = file.read(buffer)) != -1) {
                  tempJar.write(buffer, 0, bytesRead);
               }

               System.out.println(entry.getName() + " added.");
            }
            finally {
               file.close();
            }

            // Loop through the jar entries and add them to the temp jar,
            // skipping the entry that was added to the temp jar already.

            for (Enumeration entries = jar.entries(); entries.hasMoreElements(); ) {
               // Get the next entry.

               JarEntry entry = (JarEntry) entries.nextElement();

               // If the entry has not been added already, add it.

               if (! entry.getName().equals(fileName)) {
                  // Get an input stream for the entry.
               
                  InputStream entryStream = jar.getInputStream(entry);

                  // Read the entry and write it to the temp jar.

                  tempJar.putNextEntry(entry);

                  while ((bytesRead = entryStream.read(buffer)) != -1) {
                     tempJar.write(buffer, 0, bytesRead);
                  }
               }
            }

            jarUpdated = true;
         }
         catch (Exception ex) {
            System.out.println(ex);
           
            // Add a stub entry here, so that the jar will close without an
            // exception.
           
            tempJar.putNextEntry(new JarEntry("stub"));
         }
         finally {
            tempJar.close();
         }
      }
      finally {
         jar.close();
         System.out.println(jarName + " closed.");

         // If the jar was not updated, delete the temp jar file.

         if (! jarUpdated) {
            tempJarFile.delete();
         }
      }

      // If the jar was updated, delete the original jar file and rename the
      // temp jar file to the original name.

      if (jarUpdated) {
         jarFile.delete();
         tempJarFile.renameTo(jarFile);
         System.out.println(jarName + " updated.");
      }
   }
}

I am accepting your answer because it tells me what I wanted to know -- not a good answer but the right answer. I figured out the complete rewrite but it doesn't suit my needs for this project. Guess I will just use folders instead of zips...

Thanks

Glad to have been of some help.

Sorry I didn't get back to you in time with the code - got sidetracked with my "real" job I'm afraid.

:o)

Ant