Zip and Unzip from a C# program using J# runtime

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.IO;

namespace EasyZipUnZip
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.MainMenu mainMenu1;
		private System.Windows.Forms.ListView listView1;
		private System.Windows.Forms.MenuItem menuItem1;
		private System.Windows.Forms.MenuItem menuItem6;
		private System.Windows.Forms.MenuItem menuItem7;
		private System.Windows.Forms.MenuItem miOpen;
		private System.Windows.Forms.MenuItem miSave;
		private System.Windows.Forms.MenuItem miNew;
		private System.Windows.Forms.MenuItem miExit;
		private System.Windows.Forms.MenuItem miAdd;
		private System.Windows.Forms.MenuItem miExtract;
		private System.Windows.Forms.ColumnHeader columnHeader1;
		private System.Windows.Forms.ColumnHeader columnHeader2;
		private System.Windows.Forms.OpenFileDialog openFileDialog1;
		private System.Windows.Forms.SaveFileDialog saveFileDialog1;
		private System.Windows.Forms.StatusBar statusBar1;
		private System.Windows.Forms.MenuItem miRemove;
		private bool newFile = true;
		private string zipFileName = "";
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.mainMenu1 = new System.Windows.Forms.MainMenu();
			this.menuItem1 = new System.Windows.Forms.MenuItem();
			this.miNew = new System.Windows.Forms.MenuItem();
			this.miOpen = new System.Windows.Forms.MenuItem();
			this.miSave = new System.Windows.Forms.MenuItem();
			this.menuItem6 = new System.Windows.Forms.MenuItem();
			this.miExit = new System.Windows.Forms.MenuItem();
			this.menuItem7 = new System.Windows.Forms.MenuItem();
			this.miAdd = new System.Windows.Forms.MenuItem();
			this.miRemove = new System.Windows.Forms.MenuItem();
			this.miExtract = new System.Windows.Forms.MenuItem();
			this.listView1 = new System.Windows.Forms.ListView();
			this.columnHeader1 = new System.Windows.Forms.ColumnHeader();
			this.columnHeader2 = new System.Windows.Forms.ColumnHeader();
			this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
			this.saveFileDialog1 = new System.Windows.Forms.SaveFileDialog();
			this.statusBar1 = new System.Windows.Forms.StatusBar();
			this.SuspendLayout();
			// 
			// mainMenu1
			// 
			this.mainMenu1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
																					  this.menuItem1,
																					  this.menuItem7});
			// 
			// menuItem1
			// 
			this.menuItem1.Index = 0;
			this.menuItem1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
																					  this.miNew,
																					  this.miOpen,
																					  this.miSave,
																					  this.menuItem6,
																					  this.miExit});
			this.menuItem1.Text = "&File";
			// 
			// miNew
			// 
			this.miNew.Index = 0;
			this.miNew.Text = "&New";
			this.miNew.Click += new System.EventHandler(this.miNew_Click);
			// 
			// miOpen
			// 
			this.miOpen.Index = 1;
			this.miOpen.Text = "&Open";
			this.miOpen.Click += new System.EventHandler(this.miOpen_Click);
			// 
			// miSave
			// 
			this.miSave.Enabled = false;
			this.miSave.Index = 2;
			this.miSave.Text = "&Save";
			this.miSave.Click += new System.EventHandler(this.miSave_Click);
			// 
			// menuItem6
			// 
			this.menuItem6.Index = 3;
			this.menuItem6.Text = "-";
			// 
			// miExit
			// 
			this.miExit.Index = 4;
			this.miExit.Text = "&Exit";
			this.miExit.Click += new System.EventHandler(this.miExit_Click);
			// 
			// menuItem7
			// 
			this.menuItem7.Index = 1;
			this.menuItem7.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
																					  this.miAdd,
																					  this.miRemove,
																					  this.miExtract});
			this.menuItem7.Text = "&Edit";
			// 
			// miAdd
			// 
			this.miAdd.Index = 0;
			this.miAdd.Text = "&Add";
			this.miAdd.Click += new System.EventHandler(this.miAdd_Click);
			// 
			// miRemove
			// 
			this.miRemove.Enabled = false;
			this.miRemove.Index = 1;
			this.miRemove.Text = "&Remove";
			this.miRemove.Click += new System.EventHandler(this.miRemove_Click);
			// 
			// miExtract
			// 
			this.miExtract.Enabled = false;
			this.miExtract.Index = 2;
			this.miExtract.Text = "&Extract";
			this.miExtract.Click += new System.EventHandler(this.miExtract_Click);
			// 
			// listView1
			// 
			this.listView1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
				| System.Windows.Forms.AnchorStyles.Left) 
				| System.Windows.Forms.AnchorStyles.Right)));
			this.listView1.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
																						this.columnHeader1,
																						this.columnHeader2});
			this.listView1.FullRowSelect = true;
			this.listView1.GridLines = true;
			this.listView1.Location = new System.Drawing.Point(0, 0);
			this.listView1.Name = "listView1";
			this.listView1.Size = new System.Drawing.Size(308, 240);
			this.listView1.TabIndex = 0;
			this.listView1.View = System.Windows.Forms.View.Details;
			this.listView1.SelectedIndexChanged += new System.EventHandler(this.listView1_SelectedIndexChanged);
			// 
			// columnHeader1
			// 
			this.columnHeader1.Text = "File Name";
			this.columnHeader1.Width = 200;
			// 
			// columnHeader2
			// 
			this.columnHeader2.Text = "Size";
			this.columnHeader2.TextAlign = System.Windows.Forms.HorizontalAlignment.Right;
			this.columnHeader2.Width = 100;
			// 
			// saveFileDialog1
			// 
			this.saveFileDialog1.DefaultExt = "zip";
			this.saveFileDialog1.Filter = "Zip files|*.zip";
			// 
			// statusBar1
			// 
			this.statusBar1.Location = new System.Drawing.Point(0, 244);
			this.statusBar1.Name = "statusBar1";
			this.statusBar1.Size = new System.Drawing.Size(312, 22);
			this.statusBar1.TabIndex = 1;
			this.statusBar1.Text = "Ready";
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(312, 266);
			this.Controls.Add(this.statusBar1);
			this.Controls.Add(this.listView1);
			this.Menu = this.mainMenu1;
			this.Name = "Form1";
			this.Text = "Untitled - Easy Zip/UnZip";
			this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}
		/// <summary>
		/// Disable remove files from zip
		/// Disable extract from new zip
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void listView1_SelectedIndexChanged(object sender, System.EventArgs e)
		{
			miRemove.Enabled = (listView1.SelectedItems.Count > 0) && newFile;
			miExtract.Enabled = (listView1.SelectedItems.Count > 0) && (!newFile);
		}

		private void miExit_Click(object sender, System.EventArgs e)
		{
			Close();
		}
		/// <summary>
		/// Searching file name in listview
		/// </summary>
		/// <param name="fileName"></param>
		/// <returns>true if found</returns>
		private bool foundInList(string fileName)
		{
			for (int i = 0; i < listView1.Items.Count; i++)
			{
				if (fileName == listView1.Items[i].Text) return true;
			}
			return false;
		}
		/// <summary>
		/// Add file name to listView
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void miAdd_Click(object sender, System.EventArgs e)
		{
			if (openFileDialog1.ShowDialog() == DialogResult.OK)
			{
				string fileName = openFileDialog1.FileName;
				if (!foundInList(fileName))
				{
					ListViewItem fileItem = listView1.Items.Add(fileName);
					FileInfo fi = new FileInfo(fileName);
					fileItem.SubItems.Add(fi.Length.ToString());
					miSave.Enabled = true;
				}
				else
					MessageBox.Show("You can't add again this file!", Text);
			}
		}
		/// <summary>
		/// Write zip
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void miSave_Click(object sender, System.EventArgs e)
		{
			if (saveFileDialog1.ShowDialog() == DialogResult.OK)
			{
				zipFileName = saveFileDialog1.FileName;
				java.io.FileOutputStream fos = new java.io.FileOutputStream(zipFileName);
				java.util.zip.ZipOutputStream zos = new java.util.zip.ZipOutputStream(fos);
				for (int i = 0; i < listView1.Items.Count; i++)
				{
					string sourceFile = listView1.Items[i].Text;
					statusBar1.Text = sourceFile;
					java.io.FileInputStream fis = new java.io.FileInputStream(sourceFile);
					// File name format in zip file is:
					// folder/subfolder/filename
					// Let's delete drive name and replace '\' with '/':
					java.util.zip.ZipEntry ze = new java.util.zip.ZipEntry(sourceFile.Substring(3).Replace('\\','/'));
					zos.putNextEntry(ze);
					sbyte[] buffer = new sbyte[1024];
					int len;
					while((len = fis.read(buffer)) >= 0)
					{
						zos.write(buffer, 0, len);
					}
					zos.closeEntry();
					fis.close();
				}
				zos.close();
				fos.close();
				statusBar1.Text = "Ready";
				Text = zipFileName + " - Easy Zip/UnZip";
				newFile = false;
			}
		}
		/// <summary>
		/// Open zip file
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void miOpen_Click(object sender, System.EventArgs e)
		{
			if (openFileDialog1.ShowDialog() == DialogResult.OK)
			{
				listView1.Items.Clear();
				statusBar1.Text = "Reading...";
				zipFileName = openFileDialog1.FileName;
				java.io.FileInputStream fis = new java.io.FileInputStream(zipFileName);
				java.util.zip.ZipInputStream zis = new java.util.zip.ZipInputStream(fis);
				java.util.zip.ZipEntry ze;
				while ((ze = zis.getNextEntry()) != null)
				{
					if (!ze.isDirectory())
					{
						ListViewItem fileItem = listView1.Items.Add(ze.getName());
						fileItem.SubItems.Add(ze.getSize().ToString());
					}
				}
				zis.close();
				fis.close();
				statusBar1.Text = "Ready";
				Text = zipFileName + " - Easy Zip/UnZip";
				newFile = false;
				miAdd.Enabled = false;
			}
		}
		/// <summary>
		/// New zip
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void miNew_Click(object sender, System.EventArgs e)
		{
			listView1.Items.Clear();
			Text = "Untitled - Easy Zip/UnZip";
			newFile = true;
			miRemove.Enabled = false;
			miExtract.Enabled = false;
			miAdd.Enabled = true;
			zipFileName = "";
		}
		/// <summary>
		/// Extract selected files from zip
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void miExtract_Click(object sender, System.EventArgs e)
		{
			sbyte[] buf = new sbyte[1024];
			int len;
			for (int i = 0; i < listView1.SelectedItems.Count; i++)
			{
				string fileName = listView1.SelectedItems[i].Text;
				java.io.FileInputStream fis = new java.io.FileInputStream(zipFileName);
				java.util.zip.ZipInputStream zis = new java.util.zip.ZipInputStream(fis);
				java.util.zip.ZipEntry ze;
				while ((ze = zis.getNextEntry()) != null)
				{
					if (fileName == ze.getName())
					{
						// File name format in zip file is:
						// folder/subfolder/filename
						// Let's check...
						int index = fileName.LastIndexOf('/');
						if (index > 1)
						{
							string folder = fileName.Substring(0, index);
							DirectoryInfo di = new DirectoryInfo(folder);
							// Create directory if not exists
							if (!di.Exists)
								di.Create();
						}
						java.io.FileOutputStream fos = new java.io.FileOutputStream(fileName);
						while ((len = zis.read(buf)) >= 0)
						{
							fos.write(buf, 0, len);
						}
						fos.close();
						statusBar1.Text = fileName;
					}
				}
				zis.close();
				fis.close();
			}
			statusBar1.Text = "Ready";
		}
		/// <summary>
		/// Remove selected file names from listView
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void miRemove_Click(object sender, System.EventArgs e)
		{
			for (int i = listView1.Items.Count-1; i >= 0; i--)
			{
				if (listView1.Items[i].Selected)
					listView1.Items.RemoveAt(i);
			}
			miSave.Enabled = (listView1.Items.Count > 0);
		}
	}
}