Using NetBeans (with Linux)

The Panel

At the top of the screen is the Panel. It is very similar to the Windows "Taskbar". On the left side of the panel is a row of "launcher icons".

The leftmost button, the one that looks like a red hat, is the main menu button. It is similar to the Windows "Start" button.

Select the Main Menu button with the left mouse button, and you will see a menu that allows you to run applications by selecting their icons with your mouse.

Move your mouse so that the cursor moves up and down the selection of items on the menu. Notice that when you move the cursor to a menu selection with a right arrow, a sub-menu is displayed showing you more even more selections. Navigate through the menu to start the text editor. Start in the upper left corner of the screen. You'll find the text editor by going through the menu selections Applications → Accessories → Text Editor.

The window and its controls

The GNOME text editor is also known as gedit. Observe its window.

For you Windows users, it's deja-vu all over again. At the top of the window is the titlebar which shows the name of the application that is running. On the right side of the title bar are three control elements: . Directly below the titlebar is the menubar, a row of words such as File and Edit. If you press a word on the menu bar, you will be rewarded with a pulldown menu which can be used to direct the actions of the applications. Below the menu bar, you'll often find a toolbar containing many icons. These icons can be used to perform useful actions, such as opening and saving files.

Let's return to those three buttons on the right end of the titlebar. The rightmost button, , is the close windows button. This button terminates the running application and closes its window. The middle button, , is the maximize button. It expands the window to the size of the full screen. This is rarely anything you'll want to do. Only the leftmost or minimize button, , remains. This control suspends the application. There is a taskbar at the bottom of the screen that can be used to revive suspended applications.

Moving and resizing the window

If you press the leftmost mouse button within the titlebar of a window, you can drag the application to different locations within the screen.

If you move the mouse to the edges or corners of a windows, the cursor will become a two-headed arrow. If you then press and hold down the leftmost mouse button, you can change the size of a window.

Managing workspaces

You may have noticed a rectangle containing four little boxes in the middle of the panel. This is the workspace switcher.

GNOME supports four different workspaces that share a panel. Each workspace can display its own set of applications. Each box of the switcher is a miniture representation of a workspace. Clicking within the switcher "opens" other workspaces. To move an application from one workspace to another, simply drag it within the switcher. You can also right-click on the maximize button () and choose a new workspace.

The basics -- what you should already know

If you've taken CSCI 107, you should have learned about directories and files in Lab 2 of CSCI 107. If this is your first exposure to this concept, settle in for a few minutes of serious study. A file is a collection of data, generally formatted for use by a specific application, such as a database or spreadsheet. A directory is a collection of files and other subdirectories. You can think of files and directories as analogous to the structure of a file cabinet. The file corresponds to the documents you store in your file cabinet and the directories correspond to the file folders---they provide a way of grouping and organizing documents. Subdirectories are nested file folders---a folder inside of another folder.

File names

Files and directories have names. In both the Linix and Windows worlds, these names are series of directory names separated by slashes: forward slashes, /, in Linix; and backward slashes, \, in Windows. (By the way, it was Unix, the precursor of Linux, that first used the slash.) Here are example file names in both Unix and Windows:

• /home/bruce/csci/201/project.java
• \Documents and Settings\bruce\csci\201\project.java

Notice, that both of the above file names start with a slash, which means that both emanate from a special root directory. These are called absolute file names. Windows has the additional complexity that absolute file names may start with a drive letter, as in A:/autoexec.bat, to specify the drive on which the file is located. You may also notice that in our example the Windows file name contained spaces while the Unix file name did not. Although you can put a space in a Unix file name, it is not recommended and may offend true Unix gurus. Even worse, it sometimes confuses the Java system, on both Windows and Unix. For this reason, we suggest you avoid spaces in CSCI 201 file names no matter what computer you are using.

Notice that both of our example names end with ".java". In both Unix and Windows it is common for file names to end with a period followed by an extension, "java" is our examples. The extension generally identifies the type of the file. Remember that a file is a collection of data formatted for a specific application; the type of the file indicates the application. You'll be generating a lot of files with the extensions "java" and "class" this term; I'll bet you can guess the application.

Both Unix and Windows support relative file names. These names do not begin with a slash and are considered to emanate from the current directory. So, if your current directory is /usr/bin and you speak of the file X11/mwm, you are really talking about /usr/bin/X11/mwm.

Graphical display of files

Most computer users, especially those of the Macintosh sect, use directories and files with absolutely no idea of how a slash is used in a file names. They use file explorers. Many, but not all, versions of Linux have a graphical file interface called Nautilus. Your desktop should contain an icon labeled something like yourid's home that can be used to explore your Linux files.

However, we really don't do that many fancy things with files in CSCI 201, so we're going to just use the old-fashion Unix file commands. This will allow you to access your files through a network connection and, after all, it's what all the true Linux gurus do.

The shell

All operating systems have a command line processor in which you can type commands. In Windows this is often called the DOS prompt, even in Windows operating systems that aren't based on pre-historic DOS.

In Linux, this program is called the shell. The first popular Unix shell was named the Bourne shell, after its creator Steve Bourne. Today the most popular Unix shell is a revision of the Bourne shell called bash, an acronym for the Bourne again shell.

There are a couple of ways to start bash within its own terminal window. You can use main menu selections, Applications → System Tools → Terminal. However, the fastest way of obtaining a terminal window it to right-click on any unoccupied space of the desktop and bring up a small menu from which you can choose Open Terminal.

When bash is running, you'll type commands to its prompt. On most Linux systems the prompt is rather verbose: [yourid@yourmach currentdir], where yourid is your Unix user name, yourmach is the name of the Linux computer you are using, and currentdir is the name of your current directory.

Useful Linux commands

Below is a summary of the commands that you'll find useful in this course. Take a look at these commands. Do not use them, you'll be asked to use several of them in the assignment section below.

pwd	Print Working Directory: Prints the full pathname of your current directory.
cd directory	Change Directory: Changes your current directory
cd	Without an argument, cd changes your current directory to your home directory.
ls directory	List: Lists the contents of a directory or sometimes just lists a file.
ls	Without an argument, ls lists the contents of the current directory.
ls -l ...	With the -l option, ls provides a more detailed directory listing.
ls -a ...	With the -a option, ls lists "hidden" files, that is, files whose name starts with a period. By convention, most user "configuration" files start a "hidden."
ls -R ...	With the -R option, ls lists a directory and all its subdirectories.
mkdir directory	Make Directory: Creates a directory.
rmdir directory	Remove Directory: Deletes an empty directory.
rm file	Remove: Deletes a file.
cp oldfile newfile	Copy: Creates a new file that is a copy of an existing file.
more file	More: Displays a file one screenful at a time.

To learn more about working with Unix files and directories, take a look at the Unix tutorials of the Idaho State University Computer Center.

Your account has been created in such a way that, in general, only you and the CSCI 201 instructors can access files within your csci directory. If you want to learn more about Linux file permissions (and you should), take some time to read our Unix File Permissions tutorial.

[yourid@yourmach currentdir] pwd
/home/yourid

[yourid@yourmach currentdir] ls
[yourid@yourmach currentdir] ls -a
[yourid@yourmach currentdir] ls -l

The file to create

Usually in CSCI 201 you will create your programs using NetBeans; however, right now we want you to do things the old-fashioned way so that you'll have an appreciation for way the NetBeans uses files and directories. In this section you are going to create a directory called csci/201/CruelWorld containing a Java file called CruelWorld.java.

//  CruelWorld.java
//
//  Author:     Your name goes here
//  Assignment: Intro lab

public class CruelWorld
{
   public static void main (String[] args)
   {
      System.out.println ("Goodbye Cruel World!");
   }
}

[yourid@yourmach currentdir] more ~/csci/201/CruelWorld/CruelWorld.java

Starting NetBeans under Windows

Windows users can click through the start → All Programs → NetBeans 5.0 → NetBeans IDE menu sequence of selections to run NetBeans.

The Project

Like many IDEs, NetBeans uses projects to organize your work. Normally the project stores your Java program files and the instructions for building and running your compiled code within a directory on your computer. In the CSCI 201 labs we will create a project for each homework and lab assignment you complete. This keeps your work in tidy little units.

The big picture

Right below NetBeans menu bar you see a row of icons for creating files and projects and building applications. However, most of NetBeans' screen real estate is consumed with two big panels. The upper left panel has three tabs: Projects, Files, and Runtime. The right panel has two tabs: Welcome and Main.java. We'll ignore the lower left panel for this week.

System.out.println("Please, sir, I want some more.") ;

public Main() {
}

public static void main(String[] args) {
    System.out.println("Please, sir, I want some more.") ;
}

Files and Directories of NetBeans

Go over and press the Files tab in the upper-left panel. Now press on those little turnstiles on the left side of the Files panel to expand some of the entries. Try to match the "tree" shown below.

This display shows you how NetBeans manages your programming effort within a single directory with several subdirectories and files. Your code is stored within a subdirectory src. There's a subdirectory build holding the compiled Java bytecode for all the Java programs of your project. NetBeans uses a program called ant to build your code. The subdirectory nbproject contains the rather complicated files needed to control ant. One more subdirectory dist contains a Java archive, a single file used to deploy a Java application.

NetBeans uses this same directory structure for your project regardless of your operating system. This makes it possible for you to move the NetBeans project stored on your UNCA Linux account to your "home" Windows or Mac OS system. We'll talk about that a bit more next week.

[yourid@yourmach currentdir] java -jar /home/yourid/csci/201/GruelWorld/dist/GruelWorld.jar