Creating ZIP and JAR Files in Java

Creating ZIP and JAR Files in Java

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();     } }