Entry
How can I create a GUI quiz program to help me memorize information for a test using Java and Swing?
Jul 16th, 2002 08:49
Jason Stracner, http://www.innovation.ch/java/java_compile.htm
I have discovered that you can compile Java programs now with out even
having a Java compiler installed on your computer. There is a free
online service that I have been using called JXXX Compiler Service
that is available at:
http://www.innovation.ch/java/java_compile.htm
It seems that all you have to do is create your Java code files and
upload them to the service and it lets you download the resulting
class files. If there happens to be errors in your code it will
instead show you the errors from the compiler. At the time of this
writing there are three versions of the JDK compiler available for
your use these are: 1.0.2, 1.1.7 and 1.2.2.
To demonstrate some core Java concepts I will walk you through setting
up this program.
Steps:
1. Create the source code file.
I have thrown together a simple Java program for this task. For your
use you can just copy this code into a file called Tester.java.
/*
* Swing_Tester.java
*
* Created on June 12, 2002, 5:33 PM
*/
/**
*
* @author JasonStracner
*/
import java.io.*;
import java.util.*;
import java.util.ListIterator;
import java.awt.event.*;
import javax.swing.*;
public class Swing_Tester extends javax.swing.JFrame {
ArrayList questions = new ArrayList();
ArrayList answers = new ArrayList();
ArrayList explainations = new ArrayList();
int iTotalQuestionsAnswered=0;
int iTotalQuestionsAnsweredCorrectly=0;
int iCurrentQuestion;
boolean fQuestionWasAnswered;
/** Creates new form Swing_Tester */
public Swing_Tester() {
initComponents();
}
String replace(String sOriginal,
String sSearchFor,
String sReplacement) {
if (sOriginal.equals("")) return "";
String sNewString = "";
int iPosOfStr = sOriginal.indexOf(sSearchFor,0);
int iLastPos = 0;
while (iPosOfStr != -1) {
sNewString += sOriginal.substring(
iLastPos,iPosOfStr) +
sReplacement;
iLastPos = iPosOfStr + sSearchFor.length();
iPosOfStr = sOriginal.indexOf(sSearchFor,iLastPos);
}
sNewString += sOriginal.substring(iLastPos);
return sNewString;
}
private void setNewQuestion() {
txtQuestion.setText("");
iCurrentQuestion=(int)(Math.random()*questions.size());
txtQuestion.setText(txtQuestion.getText()
+ "\nQuestion:\n");
txtQuestion.setText(txtQuestion.getText()
+ (String)questions.get(iCurrentQuestion));
txtQuestion.setText(txtQuestion.getText() + "\n");
}
private void printScore() {
float rScore = (float)iTotalQuestionsAnsweredCorrectly /
(float)iTotalQuestionsAnswered * 100F;
rScore = java.lang.Math.round(rScore*10F)/10F;
txtQuestion.setText(txtQuestion.getText()
+ "\nYour score is: " + rScore + "%");
txtQuestion.setText(txtQuestion.getText() + "\n"
+ iTotalQuestionsAnsweredCorrectly
+ " out of " + iTotalQuestionsAnswered);
}
private void showExplaination(){
txtQuestion.setText(txtQuestion.getText()
+ "Explaination:\n"
+ (String)explainations.get(iCurrentQuestion));
}
private void checkAnswer() {
txtQuestion.setText(txtQuestion.getText()
+ "\n" + txtAnswer.getText());
if (txtAnswer.getText().equals(
(String)answers.get(iCurrentQuestion))) {
txtQuestion.setText(txtQuestion.getText()
+ "\n Right!\n");
iTotalQuestionsAnswered++;
iTotalQuestionsAnsweredCorrectly++;
} else {
txtQuestion.setText(txtQuestion.getText()
+ "\nWrong.");
txtQuestion.setText(txtQuestion.getText()
+ "\nThe correct answer is: '"
+ (String)answers.get(iCurrentQuestion)
+ "' not '" + txtAnswer.getText() + "'\n");
iTotalQuestionsAnswered++;
}
}
//
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
private void initComponents() {
jScrollPane4 = new javax.swing.JScrollPane();
txtQuestion = new javax.swing.JTextArea();
txtAnswer = new javax.swing.JTextField();
setFont(new java.awt.Font("Arial", 0, 10));
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowOpened(java.awt.event.WindowEvent evt) {
formWindowOpened(evt);
}
public void windowClosing(java.awt.event.WindowEvent evt) {
exitForm(evt);
}
});
txtQuestion.setEditable(false);
txtQuestion.setLineWrap(true);
txtQuestion.setWrapStyleWord(true);
jScrollPane4.setViewportView(txtQuestion);
getContentPane().add(jScrollPane4,
java.awt.BorderLayout.CENTER);
txtAnswer.setText("Type your answer here and press enter.
Press enter a second time to move to the next question.");
txtAnswer.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
txtAnswerKeyPressed(evt);
}
});
getContentPane().add(txtAnswer, java.awt.BorderLayout.SOUTH);
pack();
java.awt.Dimension screenSize =
java.awt.Toolkit.getDefaultToolkit().getScreenSize();
setSize(new java.awt.Dimension(600, 300));
setLocation((screenSize.width-600)/2,
(screenSize.height-300)/2);
}
private void txtAnswerKeyPressed(java.awt.event.KeyEvent evt) {
if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
if (fQuestionWasAnswered) {
txtAnswer.setText("");
setNewQuestion();
} else {
checkAnswer();
showExplaination();
printScore();
}
fQuestionWasAnswered = !fQuestionWasAnswered;
}
}
private void formWindowOpened(java.awt.event.WindowEvent evt) {
// Add your handling code here:
BufferedReader oBufferedReader;
String sLineOfText;
try {
oBufferedReader = new BufferedReader(
new FileReader("fill_in_the_blanks.txt"));
String sSection = "q";
String sLineToAdd = "";
while((sLineOfText = oBufferedReader.readLine())!= null) {
if (sLineOfText.indexOf("<q>")>=0) {
sSection = "q";
sLineOfText = replace(sLineOfText, "<q>","");
} else if (sLineOfText.indexOf("<a>")>=0) {
sSection = "a";
sLineOfText = replace(sLineOfText, "<a>","");
} else if (sLineOfText.indexOf("<e>")>=0) {
sSection = "e";
sLineOfText = replace(sLineOfText, "<e>","");
}
if (sLineOfText.indexOf("</q>")>=0) {
sSection = "/q";
sLineOfText = replace(sLineOfText, "</q>","");
} else if (sLineOfText.indexOf("</a>")>=0) {
sSection = "/a";
sLineOfText = replace(sLineOfText, "</a>","");
} else if (sLineOfText.indexOf("</e>")>=0) {
sSection = "/e";
sLineOfText = replace(sLineOfText, "</e>","");
}
if (sLineToAdd.equals("")) {
sLineToAdd = sLineOfText;
} else {
sLineToAdd = sLineToAdd + "\n" + sLineOfText;
}
if (sSection.equals("/q")) {
questions.add(sLineToAdd);
sLineToAdd = "";
sSection = "";
} else if (sSection.equals("/a")) {
answers.add(sLineToAdd);
sLineToAdd = "";
sSection = "";
} else if (sSection.equals("/e")) {
explainations.add(sLineToAdd);
sLineToAdd = "";
sSection = "";
}
}
oBufferedReader.close();
} catch (IOException ioe) {
JOptionPane.showMessageDialog(this,
"Couldn't open the file fill_in_the_blanks.txt.",
"Question file error:", JOptionPane.INFORMATION_MESSAGE);
System.exit(0);
};
txtAnswer.requestFocus();
txtAnswer.setSelectionStart(0);
txtAnswer.setSelectionEnd(txtAnswer.getText().length());
//Show the first question.
setNewQuestion();
}
/** Exit the Application */
private void exitForm(java.awt.event.WindowEvent evt) {
System.exit(0);
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
new Swing_Tester().show();
}
// Variables declaration - do not modify
private javax.swing.JScrollPane jScrollPane4;
private javax.swing.JTextArea txtQuestion;
private javax.swing.JTextField txtAnswer;
// End of variables declaration
}
//End of code----------------
2. Next go to the JXXX Compiler Service’s web page and choose the file
you created in step one and be sure to select the JDK version 1.2.2
so that you will have access to the new Java 2 Swing GUI libraries.
Then click ‘Compile’.
3. Wait.
4. When the browser displays the compiled class files select the file
that is a zip file. This file will contain all the class files
that are needed to run your application. Download and unzip these
files into an empty folder.
5. One of the best ways to run Java applications is to turn them into
executable JAR files. In windows you can simply double-click on an
executable JAR file and it will run just like an .exe file. Here is
how you can use the zip file we just made to turn it into an
executable JAR file.
a. Within the folder you unzipped the compiled class files into in
step four create a subfolder called “meta-inf”. Create a file in
this subfolder called “Manifest.mf”.
b. Inside this new file put a single line of text:
Main-Class: Tester
Make sure that you press the Enter key at the end of the single
line of text. I have heard of people having problems by not
having that extra character that is made by the Enter key at the
end of the manifest.mf file.
c. Use WinZip or some other zip utility to zip the class files and
the “meta-inf” folder into a zip file. The structure within the
zip file should be like this:
Tester.class
Tester$1.class
Tester$2.class
meta-inf\ Manifest.mf
d. Rename the zip file to “Tester.jar”.
e. Now as long as you have a copy of the JRE or JDK of 1.3 or
greater you can just double-click on the jar file to run the
program.
f. You will also need the ‘questions and answers’ file in order for
this program to be of much use. All you have to do to get the
thing to display you questions is to create a file that is in the
same folder as your JAR file called “fill_in_the_blanks.txt”. In
this file the program identifies the text between the <q> and
the </q> tags as a question, the text between the <a> and the
</a> as the answer and the text between the <e> and </e> tags
as the explaination for the answer. All three sections must
be present for each question. Remember that the text that you
give for the answer shouldn't contain a new line character
(The enter key) because you can only type a single line for the
answer.
I hope this helps someone out on a test or maybe helps programmers
understand some of the basic concepts of doing Java programming. If
you have any comments on this article please email me at:
article_comments@lr-tc.com.
