Question

well my question is really simple, is about an unexpected behavior (or at least is unexpected to me) while I try to zip a directory, I have the following methods that I’ve created on my own (I’m quite aware that I’m not handling exceptions and all that stuff, It is because (by now) I’m just doing this to learn how to do it so stability “is not really important”), here is the code:

public static void zipDirectory(File srcDirectory, File zipFile) throws IllegalArgumentException {
    if (!srcDirectory.isDirectory()) {
        throw new IllegalArgumentException("The first parameter (srcDirectory) MUST be a directory.");
    }
    int bytesRead;
    byte[] dataRead  = new byte[1000];
    BufferedInputStream in = null;
    ZipOutputStream zOut;
    try {
        zOut = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(zipFile)));
        for (File f : srcDirectory.listFiles()) {
            if (f.isDirectory()) {
                FileUtilities.zipInnerDirectory(f,zOut);
            }else {
                in = new BufferedInputStream(new FileInputStream(f.getAbsolutePath()), 1000);
                zOut.putNextEntry(new ZipEntry(f.getPath())); 
                while((bytesRead = in.read(dataRead,0,1000)) != -1) {
                    zOut.write(dataRead, 0, bytesRead);
                }
                zOut.closeEntry();
            }
        }
        zOut.flush();
        zOut.close();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

private static void zipInnerDirectory(File dir, ZipOutputStream zOut) throws IllegalArgumentException {
    if (!dir.isDirectory()) {
        throw new IllegalArgumentException("The first parameter (srcDirectory) MUST be a directory.");
    }
    BufferedInputStream in = null;
    int bytesRead;
    byte[] dataRead  = new byte[1000];
    try {
        for (File f : dir.listFiles()) {
            if (f.isDirectory()) {
                FileUtilities.zipInnerDirectory(f,zOut);
            }else {
                in = new BufferedInputStream(new FileInputStream(f.getAbsolutePath()), 1000);
                zOut.putNextEntry(new ZipEntry(f.getPath())); 
                while((bytesRead = in.read(dataRead,0,1000)) != -1) {
                    zOut.write(dataRead, 0, bytesRead);
                }
                zOut.closeEntry();
            }
        }
        zOut.flush();
        zOut.close();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

As I said is not my best coding so please don’t judge the code (or at least don’t be too strict 😉 ), I know it can be so much better; ok the “unexpected behavior” is this, let’s say that I have the following directory:

• H:\MyDir1\MyDir2\MyDirToZip

when i send as a parameter a file created with that path (new File("H:\\MyDir1\\MyDir2\\MyDirToZip")) everything’s work pretty fine the zip is created successfully, the thing is that when I open (unzip) the files inside the zip they have the next structure:

• H:\MyDir1\MyDir2\MyDirToZip

when I was expecting to find inside just:

• \MyDirToZip

without H: \MyDir1 \MyDir2 which are “unnecessary” (BTW they just contain one to each other in the appropriate order, i mean, the other files that are in them are not compressed, that is why I say they are unnecessary) so the question is, what I’m I doing wrong? how can I specify that I just want to zip the structure down the srcDirectory?

Answer 1

zOut.putNextEntry(new ZipEntry(f.getPath())); 

This should be the problem. f.getPath() will return a path that’s relative to some root directory (probably your current working dir), but not relative to the directory you are zipping. You need to figure out a way to get the relative path from the zip directory, possibly this will do:

new ZipEntry(f.getAbsolutePath().substring(zipDir.getAbsolutePath().length()))

or, if you want the root directory added:

new ZipEntry(zipDir.getName() + "/"
             + f.getAbsolutePath().substring(zipDir.getAbsolutePath().length()))