Create jar with particular path

Question

I create a jar file using the API (package java.util.jar).
My application works fine but it creates a jar and save this path (an example):
fileA - c:\dir1\dir2\fileA
fileB - c:\dir1\dir2\dirA\fileB
How can I create a jar file and save this path ?
fileA - fileA
fileB - dirA\fileB
Thanks in advance and sorry for my english.
Matteo

Answer 1

Alright, this package is not documented very well, so here's the help you need.
The Zip entry, "ZipEntry" really doesn't care about the path like the file structure does. It just treats the path like a name, and when extracted with a program like unzip, the extractor creates the directories specified by the names, which are paths. You should always use relative paths in a zip archieve, and most programs will transform absolute path names just because it's dangerous.
So here is a simple method that can zip up and directory tree, and take a base path off the start of the tree. In your example the arguments to this method would be...
("c:\\dir1\\dir2", new File("c:\\dir1\\dir2"), out)
In this case the base and file are the same, because you didn't want any header directories. "out" is a ZipOutputStream that you created.... There is one problem though. I was a bad kid when I made this method, and it doesn't work on windows... so you're gona have to fix that before you can use it :)
   * Writes out all directories and contents of the given file
   * and all its decendents to the ZipOutputStream. Because it
   * it is unsafe and somewhat incorrect to use absolute paths
   * in ZipEnties, the base parameter must be non-null, have
   * length > 0 and start with a File.separator.
   * @param base The path to 'subtract' off the full path for
   * each file. For instance, if a file path is
   * "/home/joe/lovenotes/kelly.txt" and the base is "/home/joe"
   * Then the file would be placed under a ZipEntry of "lovenotes/kelly.txt"
   * @param file The file to start at. If it is a file, then it will be
   * the only entry written to the stream, otherwise, it will be recursed.
   * @param out The ZipOutputStream to write to.
   * @throws IOException if an underling IOException occurs, or if
   * a base condition is not met, such as the base not being the first part
   * of the file path.
  static private void writeTree(String base, File file, ZipOutputStream out)
    throws IOException {
    if(base == null || (!file.getCanonicalPath().startsWith(base))) {
      throw new IOException("parameter 'base' incorrect: '" + base);
    if(file.isFile()) {
      String path = file.getCanonicalPath();
      base = (base.endsWith(File.separator))
        ? base.substring(0, base.length() - 1) : base;
      // An Extra +1 so the path DOES NOT have a leading separator
      path = path.substring(base.length() + 1, path.length());
      if(DEBUG > 2)
        System.out.println(path);
      ZipEntry ze = new ZipEntry(path);
      ze.setSize(file.length());
      ze.setTime(file.lastModified());
      out.putNextEntry(ze);
      writeOutBuffer(createBufferFromFile(file), out);
      out.closeEntry();
    } else {
      File[] files = file.listFiles();
      for(int i = 0; i < files.length; i++) {
        writeTree(base, files, out);