Simulate a Checkout Line at a Supermarket - Project 2 | CS 402, Study Guides, Projects, Research of Computer Science

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CS

Java Handout for Project

Simulate a Checkout Line at a

Supermarket

Implementation Help

Project2: Simulate a checkout

line at a supermarket (JApplet)

• Note:
  • ChkOutApplet.bat

appletviewer -J-Djava.security.policy=ChkOutApplet.policy ChkOutApplet.html

• ChkOutApplet.policy

grant {

permission java.security.AllPermission;

• ChkOutApplet.html

JFileChooser: showSaveDialog

and showOpenDialog method

• javax.swing.JFileChooser extends JComponent implements Accessible
• int showSaveDialog(Component parent)
  • Pops up a "Save File" file chooser dialog.
  • Return: JFileChooser.CANCEL_OPTION, JFileChooser.APPROVE_OPTION and JFileCHooser.ERROR_OPTION
• int showOpenDialog(Component parent)
  • Pops up an "Open File" file chooser dialog.
• Ex.

JFileChooser fileSelect = new JFileChooser();

int option = fileSelect.showSaveDialog (this); // showOpenDialog(this);

if (option == JFileChooser.APPROVE_OPTION) {

// statements

JFileChooser: getSelectedFile

method

• javax.swing.JFileChooser

extends JComponent

implements Accessible

• File getSelectedFile()
  • Returns the selected file.
• Ex.

JFileChooser fileSelect = new JFileChooser(); File fileName = fileselect.getSelectedFile ();

JComboBox: getSelectedIndex

method

• javax.swing.JComboBox

public class JComboBox extends JComponent

• int getSelectedIndex()
  • Returns the first item in the list that matches the given item.
• Ex.

simulate (customerArrivalRate.getSelectedIndex()+3, customerArrivalRate.getSelectedIndex()+3); int next_arrival = (int)(Math.random () * selectArrival + 1);

FileWriter and FileReader

• java.io.FileWriter

public class FileWriter

extends OutputStreamWriter

• Convenience class for writing character files.
• java.io.FileReader

public class FileReader

extends InputStreamReader

• Convenience class for reading character files.

BufferedReader: readLine

method

• java.io.BufferedReader public class BufferedReader extends Reader
  • Read text from a character-input stream, buffering characters so as to provide for the efficient reading of characters, arrays, and lines.
• String readLine()
  • Read a line of text.
• Ex. BufferedReader br = new BufferedReader(new FileReader(fileName)); outputArea.setText(""); String line; while ( (line = br.readLine() )!= null ) { outputArea.append(line); outputArea.append("\n"); } // display data in GUI br.close();

Simulate a Checkout Line at a

Supermarket

ComboBox