Java程序辅导

	
  	
  
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10403 Lab and Eclipse Introduction 
(Last updated by asanchez, jcomer 8/22/16.)  
I. Access and check your student account.  
1.  Log into the TCU network with your TCU student account Username and Password. (If your 
password does not work, try your original password - DDMMMYY of your birthday. For 
example, 05MAR79.)  
Username:  
Password:  
Domain: TCU  
If at anytime during the semester you have problems with your account or password you  
should go to Information Commons Help Desk on the first floor of the TCU Library. The  
phone number to the Help Desk is X5855. If you have Internet access, you can reset the  
password on your account by accessing https://mypw.tcu.edu/pwreset/.  
2.  Take a moment to familiarize yourself with the Windows XP desktop. Find each of the 
applications noted below. You should realize that the desktop might look a little different on 
different computers.  
Internet Explorer – The web browser you should always use to check the execution of your 
Java applet on the web.  
ECLIPSE IDE - The integrated development environment (IDE) used to create your Java 
programs. This program is available from the Start menu and may also be available from a 
desktop shortcut labeled “Computer Science Applications”.  
TURNIN - A program used to submit your Java source code for grading. This program is 
available from the Start menu and may also be available from a desktop shortcut.  
3.  Double-click on My Computer to access the various resources of this machine. Besides the 
usual C: and D: drives you should see a shared W: “//studentweb/” with your username. 
This is your TCU student drive space and the location you will store your work for 
grading. You will be able to access it from any computer connected to the TCU network or 
that can connect to the Internet.  
IF YOU CANNOT LOGIN OR DO NOT SEE YOUR W: DRIVE, STOP HERE AND GET 
ASSISTANCE IMMEDIATELY!  (Your account may not be set up correctly yet.)  
4.  It is wise to occasionally check the available storage space of your student account on your 
W: drive. To check the space you can open the W: drive (by double-clicking), from the Edit 
menu select “Select All”, right-click on the highlighted icons and select “Properties” from the 
drop-down menu. You will be shown the amount of used space on your account. Make sure to 
always keep plenty of available space for saving lab projects and your email. Most student 
accounts are given 50 Mbytes (approx. 50,000,000 bytes) of storage. If your space quota is 
exceeded you will not be able to run and save your labs correctly!  
	
  	
  
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II. Prepare a wwwpub directory on your W: drive. (Done only ONCE.)  1. At	
  this	
  point	
  you	
  need	
  to	
  obtain	
  some	
  files	
  to	
  set	
  up	
  a	
  WWWPUB	
  directory	
  on	
  your	
  W:	
  drive.	
   (Note:	
   you	
   must	
   be	
   in	
   one	
   of	
   the	
   labs	
   on-­‐campus	
   in	
   order	
   to	
   perform	
   the	
  following	
  steps).	
  	
  
For	
   Windows	
   8:	
   Right	
   click	
   the	
   bottom	
   left	
   Windows	
   icon	
   and	
   select	
   the	
   Run	
  application	
  and	
  selected	
  it	
  should	
  look	
  as	
  follows:	
  	
  
	
  
	
  
	
  
Type	
  in	
  in	
  the	
  search	
  	
  
	
  \\tcu.edu\dfs1\lab_common\COSC_10403	
  	
   and	
   hit	
   OK.	
   The	
   window	
   shown	
   below	
  should	
  appear.	
  	
  
	
  
	
  
For	
  Windows	
  7:	
  Go	
  to	
  the	
  MS	
  bottom	
  flag	
  or	
  start	
  Button	
  and	
  Select	
  Run.	
  	
  Type	
  in	
  \\labsrv1\lab_common\COSC_10403	
  	
  or	
  
	
  \\tcu.edu\dfs1\lab_common\COSC_10403	
  	
   and	
   hit	
   OK.	
   The	
   window	
   shown	
   below	
  should	
  appear.	
  	
  	
  
 
	
  	
  
 
 2.	
  	
   Open	
  MyComputer	
  by	
  double-­‐clicking	
  on	
  the	
  icon.	
  	
  	
  	
  3.	
  	
   Inside	
   the	
  window	
   just	
   opened	
   for	
  MyComputer,	
   open	
   your	
  W:	
   drive.	
   If	
   you	
   already	
  
have	
   a	
   wwwpub	
   directory	
   on	
   your	
   w:	
   drive	
   delete	
   the	
   wwwpub	
   file;	
   	
   otherwise,	
  
continue	
  with	
  Step	
  4	
  below.	
  
	
  	
  
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3	
  
	
  	
  4.	
  	
   Copy	
   the	
   entire	
  WWWPUB	
   (not	
   the	
   WWWPUB.zip)	
   directory	
   and	
   its	
   contents	
   from	
  
COSC_10403	
   onto	
   your	
  W:	
  drive.	
  NOTE	
   that	
   if	
   in	
   your	
  W:	
   there	
   is	
   already	
   a	
  previous	
  wwwpub	
  folder	
  you	
  should	
  delete	
  this	
  one	
  and	
  copy	
  the	
  new	
  one	
  	
  
 5.	
  	
   Close	
  your	
  W:	
  drive.	
  Skip	
  to	
  Step	
  7.	
  	
  
 6.	
  	
   Do	
   this	
   step	
   ONLY	
   if	
   you	
   did	
   not	
   do	
   Steps	
   4-­‐5	
   above	
   (because	
   you	
   already	
   had	
   a	
  
WWWPUB	
  directory	
  on	
  your	
  W:	
  drive).	
  Open	
  WWWPUB	
  in	
  the	
  COSC_10403	
  directory.	
  Select	
  all	
   items	
  inside	
  the	
  WWWPUB	
  directory	
  in	
  COSC_10403	
  and	
  drag	
  them	
  into	
  the	
  already	
  existing	
  WWWPUB	
  folder	
  on	
  your	
  W:	
  drive.	
  Close	
  your	
  W:	
  drive.	
  	
  
 7.	
  	
   Now	
   let’s	
   verify	
   that	
  WWWPUB	
   has	
   been	
   created	
   correctly.	
   Open	
   your	
  W:	
   drive	
   by	
  double-­‐clicking.	
   Open	
  WWWPUB	
   directory	
   on	
   your	
  W:	
   drive.	
   You	
   should	
   see	
   Lab0-­‐9	
  folders	
  and	
  a	
  10403labs.html	
  icon	
  as	
  shown	
  below.	
  If	
  you	
  do	
  not	
  see	
  a	
  window	
  with	
  the	
  
Address	
   and	
   contents	
   EXACTLY	
   as	
   shown	
   below,	
   ask	
   for	
   assistance.	
   Currently	
   the	
  folders	
  are	
  all	
  empty.	
  As	
  you	
  finish	
  each	
  lab	
  this	
  semester,	
  you	
  will	
  place	
  specified	
  files	
  in	
  the	
   appropriate	
   lab	
   folder.	
   These	
   files	
   can	
   then	
   be	
   accessed	
   from	
   a	
   web	
   browser	
   to	
  demonstrate	
  the	
  execution	
  of	
  your	
  Java	
  applet	
  for	
  grading.	
  	
  	
  
 	
  8.	
  	
   Close	
  all	
  windows	
  except	
  these	
  instructions.	
  	
  
	
  	
  
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III. Use Eclipse (version NEON) to create and run a Java applet.  
Eclipse is an open source IDE (integrated development environment) available to programmers 
who want to develop Java projects. Since it is an IDE, the tools needed for editing, compiling, 
building, debugging, executing, and obtaining online help are all integrated in one graphical user 
interface. Using these tools effectively can greatly increase your productivity. However there are 
many options available and you may get easily confused; follow these instructions to gain an initial 
feel for the IDE, later you can spend time using the various options. The current version of Eclipse 
are using is MARS. 
 
1. Before beginning, you should create a COSC10403 folder to hold all of your work related to 
this class. Note: this folder should reside on your W: drive (but outside of your wwwpub 
folder)! 
 
2. Start Eclipse by selecting Eclipse from the Start menu or by double-clicking the shortcut 
found inside the Computer Science Applications desktop folder on TTC lab computers. The 
first thing that you have to do is to select the workspace area where you will store your Eclipse 
Java Programs. This workspace will most commonly be the COSC10403 folder that you 
created in Step #1 above - so you may simply select OK after Browsing to get to that location. 
 
 
 
3. If the Eclipse Welcome Window appears, close it by clicking on the “X” to the far right of its 
title bar. (Note that the welcome page in Eclipse Neon may be a bit different) 
 
 
 
After this, you should now be observing only the File, Edit, Source … bar and the various 
Package, Tasks and empty windows (as seen in the figure below).  
 
Click Here!!   
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vvvdddyou 
You m 
	
  	
  
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4. If this is your the first time to launch Eclipse, your Package Explorer window should be 
empty indicating that you have not yet created any projects; if you have used Eclipse before 
other Java projects may be listed (for example Lab0Project, Lab1Project, Lab2Project, and so 
on). To continue working on a project that was begun earlier, simply click on the desired 
project in the Projects window and continue with the development. 
 
Note: To switch between Projects, Files, or Services windows, simply click on the desired 
window’s title bar.  
 
5. To create and run a new Java program you must first create a project.  Follow the steps below  
 
a. Choose New/Java Project… from the File menu. The screen below should appear.  
  
 
 
The following window appears - to create a new project, let us name it as Lab0Project  
and select Next. (Note: you should always name your projects as: LabiProject, where i 
will correspond to the current lab number). 
 
Make this 
selection. 
	
  	
  
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A new window appears, simply select Finish  
 
 
 
The Project Explorer window will show a new folder named Lab0Project  
 
 
6. Create an initial class for Lab0Project   
 
Name your project: 
Lab0Project 
Lab0Project 
	
  	
  
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Choose New Class… from the File menu. The screen below should appear. 
 
 
  
Name your class as Lab0, as follows: 
 
 
 
After you select Finish the right window of the IDE will display the source code for this new 
class (as shown below): 
 
 
Name your project:  
Lab0 (Note that it will be 
stored as Lab0.java) 
Make this 
selection. 
The source code of the 
selected java class is 
displayed in this window. 
	
  	
  
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7. Editing a java file.  
 
For this initial practice, replace (overwrite) the java source code in the right-side window with 
the following new java code EXACTLY as it is given here. (Otherwise you will have Java 
errors and the program will not run):  
import java.awt.*; 
import javax.swing.JApplet; 
public class Lab0 extends JApplet 
{ 
 public void init() { 
  repaint(); 
  System.out.println("hello World"); 
 } 
  
 public void paint(Graphics g) { 
  g.drawString("Hello World!", 30, 30); 
 } 
} 
Your source code window should now look like the following: 
 
 
 
 
 
 
We will be discussing the significance of each of these Java statements in class shortly but 
here is a brief explanation. The two import statements are needed to allow your program to 
access two predefined packages of Java code.  The public class is your Lab0 program and it 
consists of two methods init and paint. Each method is a set of instructions separated by 
semicolon (;) and enclosed in braces { }. The complete class is also enclosed by a pair of { }. 
 
8. Running the program  
 
To run your program you must insure that the class Lab0.java file is highlighted in the right-
side Package Explorer window.  From the top menu bar, choose the Run/Run As/Java 
Applet option as follows:  
 
Selected java reserved 
words will automatically 
be color-coded. 
	
  	
  
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Before running the program, the IDE may need to first compile your program.  If this is the 
case simply select OK.  
  
  
 
When running your program, it should open a window in the upper left corner (as shown 
below): 
 
 
 
Note that you can also run your program using the green and black arrows in the tool bar (as 
shown below) 
 
 
The Run command is part of the options in the main menu 
This window displays 
the applet class named 
Lab0 your program  
The Run command is 
also available from the 
green and bottom 
arrow icons  
Run As/Java Applet 
	
  	
  
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1. About source and binary Java Files 
 
After your program has successfully executed – an inspection will reveal that you now have 
two folders stored in your original Lab0Project folder. An src folder (containing the java 
code that you entered earlier) and a bin folder (containing a Lab0.class which is the actual 
code that will ultimately be executed by the computer). 
 
To verify this, open the COSC10403 folder. Opening a window in XP (i.e. outside Eclipse) 
you should have two subfolders in the Lab0Project, a bin and a src.  Opening the bin and src 
folders will show the screen shots below (note this is done outside of Eclipse, using the 
Windows explorer) 
 
 
 
 
 
 
 
 
 
In the bin folder you have the object code of your program Lab0.class (this is actually the code that 
the machine executes). In the src folder you will find the source code of your program Lab0.java 
(what you typed earlier). 
 
a. Saving and copying your files.   
 
Your files are automatically saved before any run command, but you can also select to 
save the file using the File …Save option once you have selected the given file.  
 
As seen in the previous windows, if you are using computers located in one of the TCU 
labs (e.g., TTC 353/357, Library, etc), your files are most likely being saved on your W: 
drive in the COSC10403 folder that you created at the beginning of the IDE session.  
In your COSC10403 folder 
you will find a subfolder for 
Lab0Project that contains 
two subfolders: src and bin The bin folder contains the 
Lab0.class file, while the src folder 
contains the Lab0.java source  	
  
	
  	
  
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If you are using your own computer, at home on in your dorm room, your files most likely 
reside on your local C: drive.  You will have to take steps to transfer both the .class and 
.java program files to your TCU W: drive in order for your work to be graded.  (We cover 
this topic in section IV of this guide). 
 
2.  Creating a New Project 
 
Back again in the Eclipse IDE, you can now use this initial template (saved now as 
Lab0.java) to create other projects.  
 
Create the new project by selecting the File/New/Java Project option and name the project 
Lab1Project (as shown in the window below): 
 
 
 
 
 
In order to create a new class, this time let us use, as a starting point, the code we created for 
Lab0.java.  
 
Select the Lab0.java code and using the Save As option from the File menu, save the class 
in the src folder of your new Lab1Project.  
 
 
Lab1Project 
	
  	
  
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See the following screen.  Note: that Lab1.java has been entered into the File name field. 
 
                                          
 
 
 
 
After selecting the OK, you now have a copy of your Lab0.java file in the src subfolder of 
your new Lab1Project.  You can use Eclipse to open it to edit this new java (as shown in the 
window below): 
 
Use the Save As to make a copy 
in the new project Lab1Project. In 
this way you now have a template 
for future projects.  
 
In this case the new name is 
Lab1.java 
 
 
	
  	
  
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Obviously the IDE expects you to correct the errors in the new program before it will run; for 
example: the class should be named Lab1 instead of Lab0 since it is located in the Lab1.java 
file. Make that correction and run the Applet again, as you did with Lab0. 
 
For the sake of practice, modify your Lab1 class by EXACTLY replacing its current source 
code with the following code: 
 
import java.awt.*; 
 import javax.swing.*; 
 public class Lab1 extends JApplet 
 {   public JButton btnStop = new JButton("STOP"); 
  public void init() { 
  add(btnStop); 
  } 
} 
Run this applet from Run  …  Run As Java Applet option using Lab1.java this time and you 
should get the following results: 
 
 
 
3.  Testing your Programs 
 
When you work on a new programming assignment you will enter Java source code for the 
new project (such as the Lab0.java file as done above) and test and retest it until everything 
looks perfect. Each time that you Run the program – Eclipse generates two files: an updated 
You have to correct the errors you have. 
The IDE marks them with red flags. For this 
case the new class should be named Lab1 
rather than Lab0. 
The new code that displays a 
button in the window applet. 	
  
Results attained after 
running the applet. 	
  
	
  	
  
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Lab1.java file and a new Lab1.class file containing the new executable code.   
 
A default internal browser (the Applet Viewer) is then used to display the applet. 
 
Once you are satisfied with your program’s results, and it is perfect – you must submit the 
assignment for grading. TWO things must be done.  
 
i. YOU MUST place the program on the web for viewing. This involves copying 
specified files into the appropriate lab folder of the WWWPUB directory on your 
W: drive. (See Section IV below) and  
 
ii.  YOU MUST submit your source code with TURNIN. (See Section V)  
 
4. Other options in Eclipse  
 
a. Occasionally, in order for your applet to be properly displayed on the web, you will have 
to make changes to the width and height parameters of the program. You can change these 
values by selecting the Run … Run Configurations option from the top menu.  From 
there select the Parameters Tab to change the width and height of the applet to be 
displayed. The default dimension is 200 pixels x 200 pixels. 
 
  
 
For example in this case we have changed the width of the window to width = 400, height = 
200.  Running the applet again yields the following results (notice the different size window):  
 
 
b. As you can see the options available in the Eclipse IDE are multiple and one can get lost 
rather easily. You will need to use Eclipse for a while in order to become comfortable with 
it. For example you can add different views in your left most window by selecting on the 
menu bar Window… Show View option as follows:  
 
Using the Run  … Run Configurations command,  
By selecting the parameters tab you can change the Width 
and Height of the applet window 
Observe the larger dimensions. 
Also, 
observe that files will be 
automatically compiled and 
saved as needed, i.e., you do not 
have to explicitly save, then 
compile, then execute. 
	
  	
  
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By using the Navigator tab you can now see both the src and bin folders for both 
projects that we’ve created (as shown below). 
 
 
 
 
 
c. Closing Eclipse 
 
To close Eclipse you only need to get out of the application by selecting the exit option (in 
the right most corner).  However, before you do that you may want to close the Applet 
you have running, you can do that by selecting the red square in the bottom window (as 
shown below)  
 
The navigator option will show you both the src and bin 
contents of your projects  
	
  	
  
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You should now have a working applet that runs inside Eclipse. Close all windows in 
preparation for the 4-step submission process outlined below. 
You can stop the execution of your applet by selecting the red 
box in the console tab 
Exit…. 
	
  	
  
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IV. Place your lab on the web (in wwwpub) and access it from a web browser.  
In order to complete an assignment, and to prepare your applet to run on the web, five steps must be 
taken. These are: 
1. Copying the contents of the assignment’s bin folder (i.e., the .class file(s)) into the 
corresponding folder in your WWWPUB folder, 
2. Prepare an html file that can be used to execute the .class file. 
 
3. Enable the URL to allow the browser to run your Applet. 
 
4. Use Firefox to validate that you applet is running properly over the web. 
 
5. Use Turnin to submit your assignment’s .java file to your instructor for grading. Note: 
this step should be done last – only after you have verified that your applet is executing 
properly over the web!! 
 
1. Step 1 – copying contents of the object code 
This step involves copying ONLY the Lab0.class from bin folder from your 
COSC10403/Lab0Project folder into the corresponding Lab0 folder in your WWWPUB 
directory on your W: drive. The procedure below should work on-campus anywhere you 
have access to your W: drive. It will also be possible to FTP from off-campus using a 
browser (https://stuftp.tcu.edu) or an FTP program such as Core FTP Lite.  
Open My Computer (by double-clicking on the icon). Open your W: drive. Open your 
COSC10403 folder and, finally, open the Lab0Project folder to view its contents. (Seen in 
the window on the left below.)  
Open the WWWPUB directory on your W: drive. Open the Lab0 folder inside your 
WWWPUB. (Seen in the window on the right below.).  It should be empty at this point.  
 
Note: The icons might appear differently depending on the operating system and 
viewing options that are set.  
Copy (DO NOT Move or Drag & Drop) the Lab0.class found in the Lab0Project 
folder into your wwwpub\Lab0 directory. Copy by right-clicking on the Lab0.class, 
	
  	
  
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selecting Copy, and then right-clicking inside the Lab0 folder and selecting Paste 
 
 
 
2. Step 2 – prepare the html file 
Write a simple html file to run your applet.  In this case you will have to write the 
following html file and save it in you wwwpub\Lab0 folder. To do this you should use 
Eclipse with the option file new Untitled Textfile File and then save it with the name 
Lab0.html in your Lab0Project Folder 
 
 
 
 
 
 
 
 
 
 
Using Eclipse this how you create an text file:  
 
 
 
Copy/Save this file into your WWWPUB\Lab0 folder and you will be able to run your 
applet from the web by pointing a browser to the .html file. 
 
 
You should use the eclipse text 
editor to write the Lab0.html file.  
Note that you may need to 
change the width=xxx and 
height=xxx parameters. 
Note that the extension may not 
show, but you have copied the 
Lab0.class file in your LAB0 folder  
	
  	
  
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3. Step 3 – Enable the URL to allow the browser to run your Applet  
In this part you will instruct java to allow applets to run in your browser. For security 
reasons you need to register the URL sites that contain secure Applets. To do this follow the 
instructions given below. 
For Windows 8: Right click the bottom left Windows icon and select Control Panel and 
search for the java panel 
  
 
 
The Lab0.html file that was created. 
Note: Firefox is the default browser.  
The applet can be tested by double-
clicking on this file or by pointing a 
browser to the file. 
  
Note that both files the Lab0.class 
and the Lab0.html are in the LAB0 
folder 
 
	
  	
  
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For Windows 7: Look for the Control Panel in Windows. Using the MS bottom flag or start 
and search for control panels as shown below: 
 
and type the word java : 
 
  
For Windows 7 or 8, click on the java icon and you will get the following control window, 
Search for control panel. 
	
  	
  
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 select the Security tab  
 
and there you have to register the following URL, this you do by editing the site list with the 
following URL’s exactly as written here: 
 
file:/// 
http://student.tcu.edu/ 
http://csfaculty.tcu.edu/10403/ 
 
 
 
 
Once this is done select Apply and OK and you are ready to test you applet 
 
 
4. Step 3 – test you applet to insure that it is running properly 
Start-up one of the Java-enabled web browsers. Graders will use Internet Explorer 6.0 (or 
later) to grade the execution of your applet on the web - so ALWAYS make sure you view 
your applets in Firefox, in Windows machines in the lab we are using the 32 bit version. On 
your laptop machine make sure that the Firefox is the 32 bit version rather than the 64 bit, 
this because the newer versions of Firefox do not allow for the java plugin. Do not use 
Google Chrome. You may also use Microsoft InternetExplorer as long as it runs the java 
plugin 
Edit the Site List 
	
  	
  
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If your account is set up correctly, you should be able to run your Lab0 applet by typing 
http://student.tcu.edu/comer1/10403labs.html (where you have to replace comer1 with 
whatever your assigned username is) for the URL and then clicking on the lab number you 
want to view, Lab #0 in this case. When running the internet explorer browser you might 
need to allow for ActiveX control, allowing the block content as follows: 
 
 
 
 
  
 
 
 
Note:  If you did not have a WWWPUB on your W: drive and have just created it for the 
first time, you will probably get the error “The page cannot be found” (shown below) when 
you try to access your 10403labs.html. This may be because the system has not yet run the 
update program to register your WWWPUB. (At last check with Technology Resources this 
update operation was being performed every hour, on the hour.)  
Try to view it again in an hour or so! If you still cannot access your Lab0 see your instructor 
immediately! You should not have this problem in future labs because the WWWPUB will 
already be created and updated  
Your applet 
executing over the 
web. 
	
  	
  
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Once your WWWPUB directory is registered you should not ever see this 
problem again.  If you do get “The page cannot be found” message, it will 
probably be because you did not correctly place a Labx.html file in the Labx 
folder (x is the lab number). 
IF THAT HAPPENS, GET IT FIXED IMMEDIATELY OR THE 
GRADER WILL ASSIGN A GRADE OF 0 !! (The grader has nothing to 
grade!!) 
Note: If you get a dialog box asking for username and password, simply enter it 
and view your web page. (This indicates that World read permissions have not been 
given to your files yet. That should happen when Technical Resources runs a 
program to update the file access privileges – currently every hour on the hour.) 
However, if this continues to happen, tell your instructor AND go talk to the TCU 
Help Desk personnel immediately!  
Always make sure you view your applet on the Web using Internet 
Explorer! Viewing the applet on the web is a major part of your lab 
grade!!!  
 
*** When you finish this operation, your W:/wwwpub/Lab0 directory should 
have the contents shown above. If it does not, ask for assistance. *** 
 
	
  	
  
25	
  
25	
  
V. Submit your Java source code (.java file) for grading – TURNIN.  
1.  Run the TURNIN program to submit the lab for grading. TURNIN is accessible from the Start 
menu or possibly from a desktop shortcut.  
a.  Enter your email address (e.g., j.doe@tcu.edu) in the box provided, select your course & 
section number, and select the assignment to be turned in (in this case, Lab0) as illustrated 
below. Click the Submit button. 
 
b.  If the information you entered was correct, AND your instructor has set up your Turnin 
account, you should be presented with a window that will allow you to navigate and find your 
.java file.  
 
You will receive a caution that only your .java file is to be turned in. DO NOT SUBMIT 
YOUR .html FILE OR YOUR .class FILE. You will get a grade of 0 (zero) if you do!!!  
Note: For some future labs you will be submitting a .zip file that will encapsulate several .java 
files together as a single file – we will discuss this later. 
 
b. Navigate to the .java file you created for Lab0 (Lab0.java in the project’s src directory) and 
click Open (or simply double-click the .java file). Be sure you only turn in the .java file with 
Turnin. 
 
 
 
	
  	
  
26	
  
26	
  
 
c.  If the submission went through correctly, you should be given a receipt number on the 
submission screen. Be sure to keep the receipt number as this is your proof that you did 
submit the lab, should any questions arise.  
 
 
 
 
 
***************Important****************  
You must run the TURNIN program to submit your lab for grading. Turnin only 
the .Java file. Always keep your receipt as proof of submission.  
Also, always verify the execution of your lab from the web using Internet Explorer 
and make absolutely sure it is submitted as the correct lab number! (This means 
going to http://stuwww.tcu.edu/username/10403labs.html and viewing the lab.)  
Later in the semester, if you experience any difficulties with the submission 
process, or viewing on the Web notify your instructor immediately!  
***************************************  
1. Your Lab 1 assignment has been posted on the 10403 Assignments web page. Go to 
http://www.cs.tcu.edu/10403 and get your Lab 1 assignment now. You may begin work on it 
today, while an instructor is available for assistance.  
 
2. Be sure to ALWAYS logoff of your account on the PC by clicking the Start menu on the Task 
bar, selecting ShutDown and Log off. If you do not do this, your account (and your labs) will 
be open to the public!  
 
	
  	
  
27	
  
27	
  
VI. Running a JApplet as a Java Application  (VERY IMPORTANT) 
      Once you have your Applet running it is also possible to run it as stand alone local Java application I 
your computer. With this you gain the versatility of the Applet in your own machine, so if for any 
reason you can not see the Applet running in the browser, ypou will be able to run it locally by a 
simple double click application. Using Eclipse and Java, you will be able to do so as it is described 
below. This is a very important part since Java Applets eventually will stop running over the 
web, so in order to show your work you will have to run your programs as Applications 
outside of Eclipse. 
1. Add a main class:  First you have to add a main method to your Applet class. Copy the 
following code and add to your Applet class:  
public static void main(String args[]) {   
        JFrame appletFrame = new JFrame("Applet as an application");   
        appletFrame.setLayout(new GridLayout(1,0));   
           appletFrame.setSize(200, 200);   
        // after the new put the name of your Applet Class 
        JApplet myApplet = new Lab1(); 
        myApplet.init();   
        myApplet.start();   
           appletFrame.add(myApplet);  
        appletFrame.setVisible(true);  
  }  
   
2. Run the applet as an application: If you read through the code of the main method you will see  
that a frame is created, this frame is a pop up window that will serve as the browser call, to run 
the applet now you will see in the Eclipse menu two options: to run as an Applet or as an 
Application: 
 
 
if you select Java Application a pop up window will appear (we call it a Frame) looking as 
follows for the case we have been working on 
	
  	
  
28	
  
28	
  
 
 
Notice it runs under the title Running as application, rather than as it did before under the 
browser as the host 
 
 
3.   Creating a clickable Jar file: Now we want to create this program as single clickable application, 
Eclipse will help doing so, by selecting the option export if you click on the directory where you have 
the applet class, as follows:  
 
when you select the export function you will get a window asking the type of java jar you want, here 
you select runnable jar as follows: 
	
  	
  
29	
  
29	
  
 
by selecting the next button a new will appear asking to select the launch configuration where you have 
to select the directory and the java class you are working on, for this example in this case Lab1. Also 
you will need to determine the export destination and the name of the jar file, for this example we have 
place it on the Desktop with the name Lab1.jar, as shown below 
 
After selecting Finish we will have the file Lab1.jar on the desktop. If just double click on it our 
application will run on the frame as shown before. 
 
The importance of this approach is that you can run this jar file in any machine that has java and it will 
run perfectly.  
 
3. Handling images in Applications: There is a very important consideration to make here when 
dealing with images. While applets can read images rather simply from the bin folder, as you 
will learn in class using the  img = getImage( getCodeBase( ), "imgFile.jpg" ); command. The 
case of Applications is different in this case you will have to change the previous line of code by 
the following one: 
           img = Toolkit.getDefaultToolkit().getImage("imgFile.jpg"); 
	
  	
  
30	
  
30	
  
Notice also that the location of the imgFile.jpg will have to be placed outside the bin folder 
and not inside otherwise the image will not be found 
 
4.  Handling Sounds in Applications: Later in the course you will also learn to add sound to your 
programs using the s = getAudioClip(getCodeBase(),"soundFile.wav"); Applet command. Again for the 
case of Application programs this will have to be changed to a more obscure code as follows: 
                       try{        File myFile = new File("soundFile.wav"); 
    s = JApplet.newAudioClip(myFile.toURI().toURL()); 
    //Or s = JApplet.newAudioClip(myFile.toURL()); 
       } 
  catch (Exception e) {} 
 
Again note also that the location of the soundFile.wav will have to be placed outside the bin folder and 
not inside otherwise the image will not be found. BUT for the time being do not worry about this last 
piece of code yet.  
 
However, it is important to note that you may be required to turn both the jar file and the source 
java later in the course using Turnin. This is done by compressing both file in a single .zip file. 
 
 
	
  	
  
31	
  
31	
  
VII. Working remotely on your own computers.  
1.  Get and install java from the site https://java.com/en/download/. Then install Eclipse version 
MARS. Eclipse provides the development environment for writing and testing Java code.  For 
Windows users Eclipse use the new installer guide https://www.eclipse.org/downloads/installer-
instructions.php. For Mac user you can install directly fro the eclipse site 
https://eclipse.org/downloads/ 
2.  Get and install TURNIN (also see the Course Policies document). If you are connected to the 
Internet (and have Java installed on your machine) you should be able to run the TURNIN program 
and submit .java files from remote locations.  
 
3.  You should be able to access your W:\wwwpub remotely (to place applets on the web for viewing) 
in one of two ways.  
 
a.  From a browser access your W: drive by going to https://stuftp.tcu.edu and login with your TCU 
username and password. You should get a screen similar to the left window shown below. 
Double-click on a directory to navigate though the directory structure (eg., into 
WWWPUB\LABx). Use the Browse button to find the files (probably on your local C: drive) 
that you wish to upload (classes directory and LABx.html file).  
 
 
b. Or by using an FTP client that supports SSH, such as Core FTP Lite for Windows machines or 
FETCH for Macs. (Go to www.coreftp.com for a free download of CoreFTP Lite.). 
 
Run CoreFTP. From the Sites menu select Site Manager and setup as shown in the window 
below. Provide your TCU username and password.  
 
 
 
 
	
  	
  
32	
  
32	
  
 
 
 
 
 
 
When you press Connect and a connection is established you should see a screen similar to the 
window below. Navigate to find the files or directories you want to move (Source) in the left 
pane and the location where you want to place them (Destination) in the right pane (shown 
below). Then simply press the appropriate blue arrow to start the transfer. 
 
4.  ******* ALWAYS verify the transfer. **********  
From Internet Explorer access http://stuwww.tcu.edu/username/10403labs.html (provide your 
username) and click on the lab you just transferred. You should see your applet run.  
	
  	
  
33	
  
33	
  
VIII. Using Eclipse 
So far we have only used a small portion of the facilities of the Eclipse IDE. Gain more familiarity with 
the IDE by using the various facilities available. Here we explore some of them. Remember always to 
BACK UP YOUR SOURCE FILES outside of Eclipse to make sure you always have a way to get 
back if for some unexpected reason your lose some files while testing the IDE.  
1. Refreshing and cleaning a project. 
Although most of the time you will be working within the IDE it may be possible that you 
modify a file of your workspace using a different editor. If this is the case when you go back to 
Eclipse be sure to select the project folder and using the right mouse button select the option 
Refresh, in this way the IDE will read the latest version in the workspace. See the following 
example:  
 
 
 
When a project has been modify externally in its source or object code it is a good practice to 
clean the object code and rebuild it. This is done by selecting the option Project… Clean of the 
menu bar as shown below 
 
 
By using the Right Mouse Button 
you have access to various 
functions 
 
Among them the Refresh updates 
the selected folder for any external 
modifications  
Using the Right Mouse Button 
you have access to various 
functions 
 
You can run your program, 
selecting the Run option 
	
  	
  
34	
  
34	
  
 
 
2. Exporting a project using a Jar.  
In Java it is customary to wrap all the object class into one single compressed file, similar to 
a zip file. In Java these files are called JAR files (Java Archived Resources). Any project 
can be turned into a Jar using the export facilities available in Eclipse. Use the Right Mouse 
Button to select the option Export and follow the sequence of windows, as presented below:  
 
From the Main Menu select  
The Clean option of Project 
 
Note that the Build 
Automatically 
Is checked so that the 
program is recompiled after 
the clean or any later 
modification is performed   
	
  	
  
35	
  
35	
  
 
 
 
Continue selecting Next until you get to the Finish and Eclipse will generate a JAR file that 
will be located in the project’s workspace. The JAR file contains all the necessary file to run 
your program, for the case of Applets, you will change the html call to specify the location 
on the desired applet, For example in this case the new html code will have the following 
applet clause: 
 
Note that in this case the file is located in the archive named Lab0Project.jar 
Select the export Java folder 
And then the Jar file  
Name the jar file, 
in this case as an 
example 
Lab0Project.jar  
	
  	
  
36	
  
36	
  
3. Documenting your code using JavaDoc 
In any programming language it is important to document your work. For the case of Java we 
use the double slash ( e.g. // ) for inline comments and the /**       */  for paragraph 
documentation. Assume we have a program that determines the Julian Number for a given date, 
the method to compute the number requires as parameters the day, the month and the year and 
returns a unique sequential number that identifies that date. A possible documentation for the 
method would look as follows: 
 /** 
    * This method computes the Julian Number 
    * @param    day     (e.g.   1 to  31 ) 
    *  @param   month  ( e.g.  1 to 12 ) 
    *  @param   year     (  e.g.  an positive integer ) 
    *  @return  Julian Number    
    */      
public int calcJDN( int day, int month, int year) { 
    //   here the code for the Julian Number method  
    //    to do     instructions  …….  
} 
 
But Java goes further in the documentation because it allows us to generate an standardized 
webpage documentation named the (Application User Interface) that we can use to learn how to 
use the specific Java class. 
 
For the sake of practice using Eclipse using the Right Button select the export option of a given 
project as we did before; however this time select the option export as Javadoc in the 
corresponding window: 
 
                
Follow the wizard windows by selecting Next, you will need to provide a name for the folder 
where you want the documentation to be placed or simple accept the default doc folder. 
Continue until you get to the Finish option. 
 
Exporting using the Javadoc option of the Java folder    
	
  	
  
37	
  
37	
  
 
 
Once you have finished you will find that you have a new folder with the documentation of the 
program. This folder contains the API documentation of your class and you can select the 
index.html file to start the navigation using any browser as follows: 
 
 
In order to get meaningful and useful information in the API it is your responsibility to 
document your source code using the /**     */  standards described before. As your get a better 
understanding of the Java language you will notice that only the public methods are documented 
in the API.  Look for the Fahrenheit Applet in the webpage of the course for a complete 
example of proper documentation of Java Programs. 
 
 
Select the index.html file of the doc folder to 
review the documentation of the Lab0 class  
	
  	
  
38	
  
38	
  
4. Converting an Applet into a stand alone Application.  
Another way to run an JApplet is to fully convert it into an Application, this is similar to what we 
did in section VI, but a bit more complete since the JApplet is transformed into an application So far 
we have been working with applets that run using a web browser to start the application. Here we 
provide a short introduction to this process. 
 Java also allows to generate stand alone programs that run as an application triggered from a local 
machine. Furthermore using the concept of a Jar we can create clickable applications that run by a 
simple click. This might not sound of little relevance, however bear in mind that we can generate 
the program in any machine (e.g. a Mac) and run the program flawlessly in a different machine (e.g. 
a WinXP) with no reprogramming or recompilation. This is an important benefit of Java.  
4.1 To show how we do this in Eclipse let us convert the Lab1Project by select “New Project” 
from the File menu. Select General/Java Application and press “Next”. Let us call the project 
Lab1App.  
 
 
 
4.2 Create a new Class for this project and named it Lab1main.  The Eclipse IDE will show 
you a set of windows to do so.  
 
	
  	
  
39	
  
39	
  
 
 
a. Let us now edit this class with the following code that resembles the code we used for the 
Lab1Applet, with some important changes we discuss below.  
      import java.awt.*; 
  
  public class Lab1main extends Frame 
  {   public Button btnStop = new Button("STOP"); 
   public Lab1main() { 
    add(btnStop); 
    this.pack(); 
    this.setVisible(true); 
   } 
   public static void main(String[ ] args) 
      {   new Lab1main(); 
       }  // trigger class 
    
   } 
	
  	
  
40	
  
40	
  
 
This code changes the Applet into a Java Application. And so rather than using an Applet we 
will use a Frame to pop up a window. Also rather than the method init() we have a new method 
named as the class itself, Lab1main. Note that we have added two lines of code: 
                        this.pack(); 
    this.setVisible(true); 
 
they are needed in order make a visible pop up window in the case of Java Applications, 
Applets are displayed directly by the web browser and that is why we did not added these lines 
in the previous case. 
 
Finally we need to create a method that will trigger the Application, this is the second method in 
the code and must be named main(). We will discuss in class all the details of it when we 
discuss applications.  
In any case, provided that you have copied verbatim the code the IDE should look as follows: 
 
and you will be able to run this method, by selecting the option as shown above. The outcome of 
this is shown below: 
Extra lines of code needed 
 
Main method required to trigger the application  
Run the program as a Java Application  
	
  	
  
41	
  
41	
  
 
 
Note that the performance of this applet is similar to the performance when we run the 
Lab1Applet. However we did not require the web browser to trigger the program.  
We can now convert this program into a Jar file in order to run it outside the IDE. For this you 
should follow the steps presented in section VII.2 of this guide. 
As we gain more familiarity with Java we will introduce other important features required in a 
Frame to be fully compatible with an Applet. Such as adding more classes and controlling the 
event of the window using a WindowListener, adding extra imports and many more.   
5. Running the Debugger using JApplets  
By now you have realized that tracing the execution of a program is a rather important part of 
your work as a programmer. This task is generally known as debugging a program, i.e. getting 
rid of the logical bugs you might have made. A simple solution to it is the use of messages sent 
to the console by means of the System.out.println() method. However a more complete help is 
to use the tools provided by the Eclipse Debugger. In this section we provide a brief 
introduction to let you get acquainted with the tool available so that you might learn to use it 
when you have a more complex programming task.  
In this guide we will use the following code, but we invite you to use any code of your previous 
labs to one feel more familiar with. 
Pop up frame displaying the Button 
	
  	
  
42	
  
42	
  
 
To start the debugging we must select the instructions we want to trace, this is done by adding 
breakpoints in the blue left side of source window where we want the program to pause. A 
breakpoint is a location in your source code that will halt execution so that you can view the 
information about a program's state. To do this right-click along the left side of the Java editor 
on the line of code you wish to break on, (Also, double-clicking on the left side of the editor will 
create a breakpoint.). See in the following figure how to toggle a breakpoint.  
 
After you do it you will see the breakpoint (a blue dot) and if you pass the mouse over it you 
	
  	
  
43	
  
43	
  
get the following message. To turn it off double click it again.   
 
 
We are now ready to run the debugger.  So far you have use the command Run As  .. Java 
Applet; but now we will use the command below in the options Debug As .. Java Applet, as 
shown in the figure 
 
 
 When	
  you	
  run	
  the	
  debugger	
  your	
  window	
  perspective	
  will	
  change	
  from	
  that	
  of	
  java	
  running	
  to	
  debugging,	
  this	
  in	
  order	
  to	
  provide	
  you	
  with	
  other	
  useful	
  windows	
  in	
  the	
  process.	
  You	
  may	
  get	
  a	
  message	
  from	
  Eclipse	
  telling	
  you	
  about	
  it,	
  as	
  shown	
  below	
  	
  
	
  	
  In	
  any	
  case	
  the	
  new	
  look	
  of	
  the	
  perspective	
  is	
  similar	
  to	
  the	
  one	
  shown	
  here:	
  	
  	
  
	
  	
  
44	
  
44	
  
	
  	
  Let	
  us	
  pay	
  attention	
  to	
  the	
  debugging	
  buttons	
  located	
  at	
  the	
  right	
  side	
  of	
  the	
  menu	
  of	
  the	
  debug	
  window:	
  
	
  	
  This	
  window	
  shows	
  the	
  live	
  stack	
  trace	
  of	
  methods.	
  When	
  	
  working	
  with	
  JApplet	
  we	
  are	
  at	
  the	
  highest	
   stack	
   level	
   object	
   so	
   in	
   order	
   to	
   get	
   down	
   to	
   a	
   breakpoint	
   select	
   couple	
   times	
   the	
  Resume	
   button 	
   	
   until	
   the	
   	
   code	
   of	
   your	
   program	
   is	
   displayed	
   in	
   the	
   source	
   window	
  showing	
  the	
  temporary	
  halt	
  at	
  the	
  selected	
  breakpoint.	
  Looking	
  at	
  the	
  Variables	
  Window	
  you	
  will	
  see	
  the	
  values	
  currently	
  assigned	
  to	
  them.	
  In	
  our	
  example	
  we	
  see	
  that	
  num1	
  =	
  9	
  and	
  myS	
  =	
  “Hello”	
  as	
  shown	
  below:	
  	
   	
  
	
  	
  
	
  	
  
45	
  
45	
  
If	
  you	
  keep	
  selecting	
  the	
  resume	
  icon	
   you	
  will	
  move	
  to	
  the	
  next	
  breakpoint.	
  Note	
  that	
  if	
  the	
  breakpoint	
  is	
  located	
  in	
  another	
  class	
  i.e.	
  another	
  program,	
  the	
  debugger	
  will	
  jump	
  into	
  it	
  and	
  deliver	
  the	
  values	
  of	
  the	
  objects	
  associated.	
  In	
  the	
  case	
  of	
  the	
  example	
  we	
  present	
  here	
  a	
  for	
  loop	
  and	
  the	
  values	
  associated	
  with	
  it	
  as	
  it	
  the	
  debugger	
  program	
  runs	
  through	
  it	
  	
  
	
  	
  
	
  	
  	
  	
  	
  The	
   debugger	
   also	
   has	
   two	
   stepping	
   buttons:	
   Step	
  Over	
   	
   	
   and	
   Step	
   Into	
   	
   .	
   Step	
   over	
  takes	
  you	
  to	
   the	
  next	
   instruction	
  within	
   the	
  code	
  and	
  Step	
   Into	
   jumps	
   into	
   the	
  code	
  when	
  a	
  method	
  is	
  called.	
  Again	
  you	
  can	
  see	
  assigned	
  value	
  for	
  the	
  variables	
  changing	
  accordingly.	
  As	
  you	
   can	
   imagine,	
   knowing	
   the	
   values	
   of	
   your	
   variables	
   eliminates	
   the	
   need	
   for	
   using	
  System.out.println()	
  statements	
  throughout	
  your	
  code.	
  Finally	
  the	
  Stop	
  button	
   	
  stops	
  the	
  execution	
  of	
  the	
  debugging.	
  You	
  can	
  debug	
  again	
  or	
  go	
  back	
  to	
  the	
  regular	
  java	
  execution	
  by	
  using	
  the	
  Run	
  As	
  command.	
  Note	
  that	
  you	
  can	
  always	
  go	
  back	
   to	
   the	
   Java	
   perspective	
   by	
   selecting	
   from	
   the	
   Window	
   Menu	
   in	
   eclipse	
   the	
   desired	
  perspective.	
  	
  	
  	
  
	
  	
  
46	
  
46	
  
	
  	
  A	
  useful	
  aspect	
  during	
  debugging	
  is	
  the	
  fact	
  that	
  you	
  can	
  change	
  the	
  internal	
  assigned	
  values	
  of	
  your	
  program,	
  for	
  example	
  assume	
  we	
  change	
  the	
  value	
  of	
  variable	
  num2	
  in	
  the	
  variables	
  window.	
  Initially	
  assigned	
  to	
  4.0	
  and	
  we	
  change	
  it	
  to	
  6.0	
  	
  
	
  if	
  we	
  step	
  over	
  the	
  code	
  using	
   	
  we	
  will	
  get	
  to	
  the	
  line	
  	
  	
  
if (num2>5) System.out.println( " Value changed for num2 " + num2  ); 
 
this line should not have not been executed, but since we have changed its value 
we will get in the console the message: value changed for num2 6.0. There are many 
other features available for debugging such as establishing watchpoints. We have provided 
only an introduction. We recommend you look at the following informative links:  
 
http://agile.csc.ncsu.edu/SEMaterials/tutorials/eclipse-
debugger/http://www.vogella.com/articles/EclipseDebugging/article.html