prendi i vari pezzi di codice che ti abbiamo postato e li metti assieme nn è difficile

This example reads a ZIP file and decompresses the first entry.
codice:
   try {
        // Open the ZIP file
        String inFilename = "infile.zip";
        ZipInputStream in = new ZipInputStream(new FileInputStream(inFilename));
    
        // Get the first entry
        ZipEntry entry = in.getNextEntry();
    
        // Open the output file
        String outFilename = "o";
        OutputStream out = new FileOutputStream(outFilename);
    
        // Transfer bytes from the ZIP file to the output file
        byte[] buf = new byte[1024];
        int len;
        while ((len = in.read(buf)) > 0) {
            out.write(buf, 0, len);
        }
    
        // Close the streams
        out.close();
        in.close();
    } catch (IOException e) {
    }
aggiungi i file alla cartella scomp e poi
ricompatti
codice:
// These are the files to include in the ZIP file
    String[] filenames = new String[]{"filename1", "filename2"};
    
    // Create a buffer for reading the files
    byte[] buf = new byte[1024];
    
    try {
        // Create the ZIP file
        String outFilename = "outfile.zip";
        ZipOutputStream out = new ZipOutputStream(new FileOutputStream(outFilename));
    
        // Compress the files
        for (int i=0; i<filenames.length; i++) {
            FileInputStream in = new FileInputStream(filenames[i]);
    
            // Add ZIP entry to output stream.
            out.putNextEntry(new ZipEntry(filenames[i]));
    
            // 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();
    } catch (IOException e) {
    }