Verify Area Code

/*--------------------------------------------------
* VerifyAreaCode.java
*
* Example from the book:     Core J2ME Technology
* Copyright John W. Muchow   http://www.CoreJ2ME.com
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class VerifyAreaCode extends MIDlet implements CommandListener
{
  private Display display;      // Reference to Display object
  private Form fmMain;         // The main form
  private Command cmTest;      // Next label and message
  private Command cmExit;      // Command to exit the MIDlet
  private TextField tfPhone;   // Phone number
  private String areaCodeTable [][] = {
                                    {"512", "912"}, // Old area code, new area code
                                    {"717", "917"} };   
    
  public VerifyAreaCode()
  {
    display = Display.getDisplay(this);

    // Create commands
    cmTest = new Command("Test", Command.SCREEN, 1);
    cmExit = new Command("Exit", Command.EXIT, 1);

    // Textfield for phone number
    tfPhone = new TextField("Phone:", "", 10, TextField.PHONENUMBER);

    // Create Form, add Commands & textfield, listen for events
    fmMain = new Form("Area Codes");    
    fmMain.addCommand(cmExit);
    fmMain.addCommand(cmTest);    
    fmMain.append(tfPhone);
    fmMain.setCommandListener(this);   
  }

  // Called by application manager to start the MIDlet.
  public void startApp()
  {
    display.setCurrent(fmMain);
  }

  public void pauseApp()
  { }
  
  public void destroyApp(boolean unconditional)
  { }

  public void commandAction(Command c, Displayable s)
  {
    if (c == cmTest)
    {
      if (tfPhone.size() == 10)
      {
        char buffer[] = new char[10];

        // Get phone number into byte array         
        tfPhone.getChars(buffer);

        // Call method to check the area code table.
        // Create a new StringItem to display, 
        // passing in 'null' as the StringItem
        StringItem tmp = new StringItem(null, ("The area code " + (areaCodeLookup(buffer) ? "has" : "has not") + " been updated."));
        
        // Place at the end of the form
        if (fmMain.size() == 1)  // Only tfPhone on form
          fmMain.append(tmp);
        else                      // Replace previous StringItem
          fmMain.set(1, tmp);
      }
    }
    else if (c == cmExit)
    {
      destroyApp(false);
      notifyDestroyed();
    } 
  }

  /*--------------------------------------------------
  * Compare the area code the user entered with the 
  * area code table. If a match is found, replace
  * the user's code with the new code from the table
  *-------------------------------------------------*/  
  private boolean areaCodeLookup(char [] buffer)
  {
    // Get the area code (only) from the users entry
    String str = new String(buffer, 0, 3);
    
    for (int x = 0; x < areaCodeTable.length; x++)
    {
      // If we find a match in the table
      if (str.equals(areaCodeTable[x][0]))
      {
        // Delete the area code
        tfPhone.delete(0, 3);
        
        // Insert the new area code
        tfPhone.insert(areaCodeTable[x][1].toCharArray(), 0, 3, 0);
        return true;
      }
    }
    return false;
  }
}
Related examples in the same category

1.	Create Form With Items
2.	GUI Test in MIDlet
3.	Login Midlet
4.	Change Label Text
5.	Form Scroll
6.	Form Juggle
7.	Form Example MIDlet
8.	Display Stats
9.	Read Display File
Verify Area Code : Form « J2ME « Java

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