In Java: How to zip file from byte[] array?

I have the same problem but i needed a many files in a zip.

 protected byte[] listBytesToZip(Map<String, byte[]> mapReporte) throws IOException {
    String extension = ".pdf";
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    ZipOutputStream zos = new ZipOutputStream(baos);
    for (Entry<String, byte[]> reporte : mapReporte.entrySet()) {
        ZipEntry entry = new ZipEntry(reporte.getKey() + extension);
        entry.setSize(reporte.getValue().length);
        zos.putNextEntry(entry);
        zos.write(reporte.getValue());
    }
    zos.closeEntry();
    zos.close();
    return baos.toByteArray();
}

You can use Java's java.util.zip.ZipOutputStream to create a zip file in memory. For example:

public static byte[] zipBytes(String filename, byte[] input) throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    ZipOutputStream zos = new ZipOutputStream(baos);
    ZipEntry entry = new ZipEntry(filename);
    entry.setSize(input.length);
    zos.putNextEntry(entry);
    zos.write(input);
    zos.closeEntry();
    zos.close();
    return baos.toByteArray();
}