actionexample.java

window下使用j2ee的jms工具做的网络应用的一个架构程序

/* Now you will be able to perform actions when a button is clicked
to get and place text in/out a textfield and to get the state of checkboxes.
This example will only let the button do actions.
*/

import java.awt.*;
import java.applet.*;
// import an extra class for the ActionListener
import java.awt.event.*;

// Tells the applet you will be using the ActionListener methods.

public class ActionExample extends Applet implements ActionListener
{

	Button okButton;
	Button wrongButton;
	TextField nameField;
	CheckboxGroup radioGroup;
	Checkbox radio1;
	Checkbox radio2;
	Checkbox radio3;
	
	
	
	public void init() 
	{
		// Now we will use the FlowLayout
		setLayout(new FlowLayout());
		okButton = new Button("Action!");
		wrongButton = new Button("Don't click!");
		nameField = new TextField("Type here Something",35);
		radioGroup = new CheckboxGroup();
		radio1 = new Checkbox("Red", radioGroup,false);
		radio2 = new Checkbox("Blue", radioGroup,true);
		radio3 = new Checkbox("Green", radioGroup,false);
		add(okButton);
		add(wrongButton);
		add(nameField);
		add(radio1);
		add(radio2);
		add(radio3);
		
		// Attach actions to the components
		okButton.addActionListener(this);
		wrongButton.addActionListener(this);
	}
	
	// Here we will show the results of our actions
	public void paint(Graphics g)
	{
		// If the radio1 box is selected then radio1.getState() will
		// return true and this will execute
		if (radio1.getState()) g.setColor(Color.red);
		// If it was not red we'll try if it is blue
		else if (radio2.getState()) g.setColor(Color.blue);
		// Since always one radiobutton must be selected it must be green
		else g.setColor(Color.green);
		
		// Now that the color is set you can get the text out the TextField
		// like this
		g.drawString(nameField.getText(),20,100);
	}

	// When the button is clicked this method will get automatically called
	// This is where you specify all actions.
	
	public void actionPerformed(ActionEvent evt) 
	{
		// Here we will ask what component called this method
		if (evt.getSource() == okButton) 
		{	
			// So it was the okButton, then let's perform his actions
			// Let the applet perform Paint again.
			// That will cause the aplet to get the text out of the textField
			// again and show it.
			repaint();
		}
		
		// Actions of the wrongButton
		else if (evt.getSource() == wrongButton) 
		{
			
			// Change the text on the button for fun
			wrongButton.setLabel("Not here!");
			// Changes the text in the TextField
			nameField.setText("That was the wrong button!");
			// Lets the applet show that message.
			repaint();
		}
	}	
	
}


// That gives you an idea of how to implement actions.
// Note that clicking the radiobuttons only shows it's effect when the
// applet is repainted. That is because no ActionListener is added
// to the radio buttons. You can do that in the same way as the buttons.

// Next example is about MouseListener, a way to let the user interact with mouse-clicks.

// Go to MouseClickExample.java