Question

That’s it. I have a text file, and I need to move it to a (existing) Zip File in a given directory.

    File file = new File("C:\\afolder\\test.txt");
    File dir = new File(directoryToGo+"existingzipfile.zip");
    boolean success = file.renameTo(new File(dir, file.getName()));

But it does not work. Is there a way to move a file into a existing Zip File?
Thank you.

Answer 1

Hmm you could use something like:

public static void addFilesToExistingZip(File zipFile, File[] files) throws IOException {
    // get a temp file
    File tempFile = File.createTempFile(zipFile.getName(), null);
    // delete it, otherwise you cannot rename your existing zip to it.
    tempFile.delete();
    boolean renameOk = zipFile.renameTo(tempFile);
    if (!renameOk) {
        throw new RuntimeException(
                "could not rename the file " + zipFile.getAbsolutePath() + " to " + tempFile.getAbsolutePath());
    }
    byte[] buf = new byte[1024];
    ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile));
    ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile));
    ZipEntry entry = zin.getNextEntry();
    while (entry != null) {
        String name = entry.getName();
        boolean notInFiles = true;
        for (File f : files) {
            if (f.getName().equals(name)) {
                notInFiles = false;
                break;
            }
        }
        if (notInFiles) { // Add ZIP entry to output stream.
            out.putNextEntry(new ZipEntry(name)); // Transfer bytes from the ZIP file to the output file
            int len;
            while ((len = zin.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
        }
        entry = zin.getNextEntry();
    } // Close the streams
    zin.close(); // Compress the files
    for (int i = 0; i < files.length; i++) {
        InputStream in = new FileInputStream(files[i]); // Add ZIP entry to output stream.
        out.putNextEntry(new ZipEntry(files[i].getName())); // Transfer bytes from the file to the ZIP file
        int len;
        while ((len = in.read(buf)) > 0) {
            out.write(buf, 0, len);
        } // Complete the entry
        out.closeEntry();
        in.close();
    } // Complete the ZIP file
    out.close();
    tempFile.delete();
}

Reference:

• http://www.dzone.com/snippets/adding-files-existing-jar-file