在 NetBeans IDE 中使用 Java Web Start(2)

Coding the Converter.java MIDP Form

1. In the Projects window, right-click the myconverter package. Choose File > New File/Folder.
   The New File wizard opens.
2. Under Categories, expand MIDP, then expand MIDP Forms. Under File Types choose MIDP Form. Click Next.
3. In the Name and Location page, enter Converter for the class name. Click Finish.
   A MIDP form is created and added to the myconverter package.
4. In the Source Editor, add the following fields to the code below the public class Converter declaration:
   

   private ConverterMIDlet midlet;
   private int[] translate;           

5. Add the following code to complete the constructor, so it looks like the sample below:
   

   public Converter(ConverterMIDlet midlet) {
       super("Currency Converter");
       this.midlet = midlet;
       this.translate = new int[midlet.currencies.length];
       int current = 0;
       for (int i=0; i<translate.length; i++) {
           if (midlet.selected[i]) {
               translate[current++] = i;
               append(new TextField(midlet.currencies[i], "", 12, TextField.NUMERIC));
           }
       }
       try {
           // Set up this form to listen to command events
          setCommandListener(this);
           // Set up this form to listen to changes in the internal state of its interactive items
          setItemStateListener(this);
           // Add the Currencies command
          addCommand(new Command("Currencies", Command.OK, 1));
          // Add the Exit command
         addCommand(new Command("Exit", Command.EXIT, 1));
     } catch(Exception e) {
         e.printStackTrace();
     }
   }
   

6. Add the following code to complete the method commandAction(), so it looks like the sample below:

 public void commandAction(Command command, Displayable displayable) {
    if (command.getCommandType() == Command.EXIT) {
        midlet.destroyApp(true);
    } else if (command.getCommandType() == Command.OK) {
        midlet.showSettings();
    }
 }

7. Add the following code to complete the itemStateChanged() method, so it looks like the sample below:

public void itemStateChanged(Item item) {
   try {
       long value = Long.parseLong(((TextField)item).getString());
       int from = 0;
       while (get(from) != item) from++;
       from = translate[from];
       for (int i=0; i<size(); i++) {
           int to = translate[i];
           if (from != to) {
              ((TextField)get(i)).setString(String.valueOf(midlet.convert(value, from, to)));
           }
        }
    } catch (NumberFormatException nfe) {
        for (int i=0; i<size(); i++) {
            ((TextField)get(i)).setString("");
        }
    }
}
 

This completes the Converter.java form file.

Coding the CurrenciesSelector.java MIDP List

1. In the Projects window, right-click the myconverter package. Choose File > New File/Folder.
   The New File wizard opens.
2. Under Categories, expand MIDP, then expand MIDP Forms. Under File Types choose MIDP List. Click Next.
3. In the Name and Location page, enter CurrenciesSelector for the class name. Click Finish.
   A MIDP list file is created and added to the myconverter package.
4. After the line public class CurrenciesSelector extends List implements CommandListener {, declare a field:
   

   private ConverterMIDlet midlet;

5. Add the following code to complete the constructor, so it looks like the sample below:
   

      public CurrenciesSelector(ConverterMIDlet midlet) {
           super("Select Currencies", List.MULTIPLE, midlet.currencies, null);
           this.midlet = midlet;
           setSelectedFlags(midlet.selected);
           try {
               // Set up this list to listen to command events
               setCommandListener(this);
               // Add the Save command
               addCommand(new Command("Save", Command.OK, 1));
           } catch(Exception e) {
               e.printStackTrace();
           }
       }

6. Add the following code to complete the method commandAction(), so it looks like the sample below:

    public void commandAction(Command command, Displayable displayable) {
        if (command.getCommandType() == Command.OK) {
            getSelectedFlags(midlet.selected);
            midlet.notifySettingsChanged();
        }
    }

This completes the CurrenciesSelector.java list file.

Creating a New Project Configuration

1. Choose File > "NewCurrencyConverter" Properties.
2. Click the Manage Configurations button.
   The Project Configuration Manager opens.
3. Click the Add Button.
   The Add Configuration button displays.
4. Name the new configuration QwertyDevice. Click Ok.
5. Click Close to close the Project Configuration Manager.

You now have a second configuration, QwertyDevice, that has the same properties as the DefaultConfiguration.

Changing the Device Property

1. While still in the Project Properties, choose Platform from the tree menu in the left pane of the window.
2. If it QwertyDevice is not shown as the active project configuration, choose it from the Project Configuration dropdown menu.
3. So that you can choose new values for this configuration, Uncheck the "Use Values from DefaultConfiguration" check box.
4. Choose QwertyDevice from the Device dropdown menu. Click OK.

Running the Application on Both Configurations

1. Make sure that the Configuration dropdown menu on the toolbar lists DefaultConfiguration as the active project configuration.
2. Choose Run > Run Main Project.
   The Currency Converter opens in the DefaultColorPhone Device emulator screen.
3. Choose QwertyDevice from the Configuration dropdown menu in the toolbar.
4. Choose Run > Run Main Project.
   The Currency Converter opens in the QwertyDevice Device emulator screen.
5. Now you can test and compare the application's performance on different devices at the same time.