Unzip an archive.

Unzip.java

import java.io.File;
import java.io.InputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

public class Unzip {

    public static void unzip(String path) throws IOException {
        File input_file = new File(path);
        ZipFile archive = new ZipFile(input_file);
        Enumeration<? extends ZipEntry> entries = archive.entries();

        byte[] buffer = new byte[8192];
        while(entries.hasMoreElements()) {
            ZipEntry entry = (ZipEntry)entries.nextElement();

            File file = new File(entry.getName());
            if (entry.isDirectory()) {
                file.mkdirs();
            } else {
                File parent = file.getParentFile();
                if (parent != null) {
                    file.getParentFile().mkdirs();
                }

                File output_file = input_file.getParentFile() != null ?
                    new File(input_file.getParentFile(), entry.getName()) :
                    new File(entry.getName());
                InputStream istream = archive.getInputStream(entry);
                FileOutputStream ostream = new FileOutputStream(output_file);
                int len;
                while((len = istream.read(buffer)) > 0) {
                    ostream.write(buffer, 0, len);
                }

                istream.close();
                ostream.close();
            }
        }

        archive.close();
    }

    public static void main(String[] args) {
        if (args.length < 1) {
            System.err.println("no file");
        }

        try {
            unzip(args[0]);
        } catch (Exception e) {
            System.err.println(e.getMessage());
        }
    }
}