JarEntry has a size of 0

Question

I am trying to read a few entries from one jar, and add them to another jar. But, when I do, I get an error saying that the size of the entries are 0. Here is my code:
//Read the entries in from the origenal JAR
     List ResourceJarEntries = new Vector();                    
     JarInputStream resourceIn = new JarInputStream(
          new BufferedInputStream(
               new FileInputStream("GeneTreeResources.jar")));
     while (resourceIn.available() != 0){
          JarEntry temp = resourceIn.getNextJarEntry();
          System.out.println(temp);
          if (temp != null){
               System.out.println(temp.getSize());
               ResourceJarEntries.add(temp);
     resourceIn.close();
//Write the resources to a new JAR
     JarOutputStream resourceOut = new JarOutputStream(
          new BufferedOutputStream(
               new FileOutputStream(
                    new File("NewResources.jar"))));
     Iterator origenalEntries = ResourceJarEntries.iterator();
     while(origenalEntries.hasNext()) {
          JarEntry next = (JarEntry)origenalEntries.next();
                //Don't save if they where in the saved_trees directory
          if (next.toString().indexOf("saved_trees") == -1) {
               resourceOut.putNextEntry(next);
     resourceOut.flush();
     resourceOut.close();The output I get from the reading demonstrates that the entries being read don't have a valid size:
male.GIF
-1
papyrus.gif
-1
female.GIF
-1
luke/steve/genetree/Resources.class
-1
saved_trees/Map.xml
-1
saved_trees/MapPanel.xml
-1
saved_trees/TestPanel.xml
-1
saved_trees/testAgain.xml
-1
null
And the Error measage in the putNextEntry just seconds that:
java.util.zip.ZipException: invalid entry size (expected 1925 but got 0 bytes)
If I read some of the JarEntries from the disk I do not get this error for those entries, but I would for every one I read from the other JAR. Any help on how I can get the full JarEntry with proper size from the origenal JAR?
thanks.

Answer 1

A while back I tried to do something similar, I finally got it to work with the following code:
     private final byte[] chunk = new byte[1024 * 1024];
     public void shift(final ZipFile inFile,
                      final File outFile)
          if ((inFile != null) && (outFile != null))
               ZipInputStream zis = null;
               ZipOutputStream zos = null;
               try
                    Manifest manifest = null;
                    final String inFileName = inFile.getName();
                    if (inFileName.endsWith(".jar"))
                         zis = new JarInputStream(new FileInputStream(inFileName));
                         manifest = ((JarInputStream) zis).getManifest();
                    else
                         zis = new ZipInputStream(new FileInputStream(inFileName));
                    if (outFile.getName().endsWith(".jar"))
                         if (manifest != null)
                              zos = new JarOutputStream(
                                        new FileOutputStream(outFile), manifest);
                         else
                              zos = new JarOutputStream(
                                        new FileOutputStream(outFile));
                    else
                         zos = new ZipOutputStream(new FileOutputStream(outFile));
                    ZipEntry entry;
                    String entryName;
                    while ((entry = zis.getNextEntry()) != null)
                         entryName = entry.getName();
                         if (!entryName.equals("MANIFEST.MF"))
                              zos.putNextEntry(entry);
                              int length = 0;
                              while (length > -1)
                                   zos.write(chunk, 0, length);
                                   length = zis.read(chunk, 0, chunk.length);
                              zos.closeEntry();
                         zis.closeEntry();
               catch (Exception ex)
//                    System.err.println(ex.toString());
                    ex.printStackTrace();
               finally
                    closeStream(zis);
                    closeStream(zos);
     }I'll leave it to you to make the neccessary adjustments to fit your specific problem ;-)
The two closeStream methods are trivial: check for null and if not close the stream in an eneveloping try-catch-block.