Using unzip from unix in java-code ...

Question

Hi people,
i have problem, i want to use the command unzip from unix, to unzip a zip-file, the commend unzip must invoke from java-code. Can someone help me. I use the zip-api, but i have 100Mb zip-file, it needs very long time to unzip the zip-file.
thanks for your help ...

Answer 1

ok, not sure how much improvement this will give in general, but its given a reliable 25% speed increase on my mini tests
using the nio libraries will also get you a lot further, and is the way to go if you are very keen on speed
asjf
import java.awt.*;
import java.io.*;
import java.util.*;
import java.util.zip.*;
import javax.swing.*;
public class Unzipper {
     private Unzipper() {}
     private static byte[] buffer = new byte[16384];
     public static void unzip(File file, Component parentComponent,     File outputDir) throws ZipException, IOException {
          unzip(new ZipFile(file), parentComponent, outputDir);
     public static void unzip(File file, int mode, Component parentComponent, File outputDir) throws IOException {
          unzip(new ZipFile(file, mode), parentComponent, outputDir);
     public static void unzip(String name, Component parentComponent, File outputDir)     throws IOException {
          unzip(new ZipFile(name), parentComponent, outputDir);
     public static void unzip(ZipFile zip, Component parentComponent, File outputDir)     throws IOException {
          if ( zip == null) {
               throw new NullPointerException("outputDir is null");
          int size = zip.size();
          if (size > 0) {
               if (outputDir == null) {
                    throw new NullPointerException("outputDir is null");
               if (!outputDir.exists()) {
                    outputDir.mkdirs();
               ProgressMonitor monitor =
               new ProgressMonitor(parentComponent,
               "Unpacking " + zip.getName() + "...", "", 0, size);
               monitor.setMillisToDecideToPopup(0);
               monitor.setMillisToPopup(0);
               Enumeration entries = zip.entries();
               for ( int i = 0; entries.hasMoreElements(); ) {
                    ZipEntry entry = (ZipEntry) entries.nextElement();
                    /*if (entry.getMethod() == ZipEntry.DEFLATED)
                    System.out.println(" Inflating: "+entry.getName());
                    else
                    System.out.println(" Extracting: "+entry.getName());*/
                    monitor.setNote(entry.getName());
                    File File = new File(outputDir, entry.getName());
                    File.getParentFile().mkdirs();
                    if (!entry.isDirectory()) {
                         InputStream in = null;
                         OutputStream out = null;
                         try {
                              in = zip.getInputStream(entry);
                              out = new FileOutputStream(File);
                              for (int n = 0; (n = in.read(buffer)) > -1; )
                                   out.write(buffer, 0, n);
                              monitor.setProgress(++i);
                         } finally {
                              if (out != null) {
                                   try {
                                        out.close();
                                   } catch (IOException e) {
     public static void main(String[] args) throws ZipException, IOException
          if (args.length !=2) {
               System.err.println("Usage: java Unzipper <zip file> <output dir>");
               System.exit(1);
          long start = -System.currentTimeMillis();
          unzip(args[0], null, new File(args[1]));
          System.out.println(start+System.currentTimeMillis());
          System.exit(0);