import java.util.zip.*;  import java.io.*;       public class ZipIt {      public static void main(String args[]) throws IOException {          if (args.length < 2) {              System.err.println("usage: java ZipIt Zip.zip file1 file2 file3");              System.exit(-1);          }          File zipFile = new File(args[0]);          if (zipFile.exists()) {              System.err.println("Zip file already exists, please try another");              System.exit(-2);          }          FileOutputStream fos = new FileOutputStream(zipFile);          ZipOutputStream zos = new ZipOutputStream(fos);          int bytesRead;          byte[] buffer = new byte[1024];          CRC32 crc = new CRC32();          for (int i=1, n=args.length; i < n; i++) {              String name = args[i];              File file = new File(name);              if (!file.exists()) {                  System.err.println("Skipping: " + name);                  continue;              }              BufferedInputStream bis = new BufferedInputStream(                  new FileInputStream(file));              crc.reset();              while ((bytesRead = bis.read(buffer)) != -1) {                  crc.update(buffer, 0, bytesRead);              }              bis.close();              // Reset to beginning of input stream              bis = new BufferedInputStream(                  new FileInputStream(file));              ZipEntry entry = new ZipEntry(name);              entry.setMethod(ZipEntry.STORED);              entry.setCompressedSize(file.length());              entry.setSize(file.length());              entry.setCrc(crc.getValue());              zos.putNextEntry(entry);              while ((bytesRead = bis.read(buffer)) != -1) {                  zos.write(buffer, 0, bytesRead);              }              bis.close();          }          zos.close();      }  }