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1. Introduction | |
2. Hello World Example | |
3. More complex example using dialog boxes | |
4. Example with content pane. |
Java Swing includes a class JApplet contained in the javax.swong package) which replaces the Applet found in previous examples. A trivail example using the JApplet class is presented below in Table 1:
The copde given in Table 1 is the the standrad "Hello World" program as a JApplet.
// Hello World Japplet Example // Frans Coenen // 13 June 3003 // University of Liverpool // Java Core Packages import java.awt.Graphics; // Jave extension packages import javax.swing.JApplet; public class HelloWorldJApplet extends JApplet { public void paint(Graphics g) { // Call super class constuctors super.paint(g); // Hello word g.drawString("Helo Word in a JApplet",25,25); } } |
Table 1: Hellow Word JApplet
The code presented in Table 2 gives a more complex JApplet using input and message dialog boxes.
// ADDITION Japplet Example // Frans Coenen // 13 June 3003 // University of Liverpool // Java Core Packages import java.awt.Graphics; // Jave extension packages import javax.swing.*; public class AdditionJApplet extends JApplet { /* ------ FIELDS ------ */ int num1, num2 = 0; boolean errorFlag=false; final int START = 1; final int END = 10; /* INITILISE JAPPLET */ public void init() { String stNum1, stNum2; try{ // Get first number] while (true) { stNum1 = JOptionPane.showInputDialog("Enter first integer value between " + START + " and " + END); num1 = Integer.parseInt(stNum1); if (num1>=START && num1<=END) break; JOptionPane.showMessageDialog(null,"ERROR 1: Input for first integer value " + " must be a between " + START + " and " + END); } // Get second number while (num2 |
Table 2: More complicated JApplet
Here is the applet:
Code in Table 3 retrieves the applrets content pane and then adds to this.
// TEXT AREA Japplet Example // Frans Coenen // 13 June 3003 // University of Liverpool // Java Core Packages import java.awt.*; import java.awt.event.*; // Jave extension packages import javax.swing.*; public class TextAreaJApplet extends JApplet implements ActionListener { /* ------ FIELDS ------ */ JTextArea textArea1, textArea2; /* INITILISE JAPPLET */ public void init() { // Get the applet's GUI component display area Container container = getContentPane(); container.setBackground(Color.pink); container.setLayout(new FlowLayout()); // Text area 1 String string = "Some text in here, Some text in here, Some text in here"; textArea1 = new JTextArea(string, 10, 15); container.add(new JScrollPane(textArea1)); // Copy button JButton copyButton = new JButton("COPY"); copyButton.addActionListener(this); container.add(copyButton); // Text area 2 textArea2 = new JTextArea(10, 15); textArea2.setEditable(false); container.add(new JScrollPane(textArea2)); } public void actionPerformed(ActionEvent event) { textArea2.setText(textArea1.getSelectedText()); } } |
Table 3: JApplet with content pane
Here is the applet:
Created and maintained by Frans Coenen. Last updated 14 June 2003