weightconventer.java

JAVA不同星球重力转换程序

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class WeightConventer extends Applet implements ActionListener
{
	WeightConvent weightInEarth=new WeightConvent();

	Button b1,b2;
	Label lab1,lab2;
	TextField text1,text2;
    public void init()
    {
    	lab1=new Label("输入地球上的重量");
    	add(lab1);
    	text1=new TextField(20);
    	add(text1);
    	text1.addActionListener(this);
    	
    	lab2=new Label("相应月球上的重量");
    	add(lab2);
    	text2=new TextField(20);
    	add(text2);
    	
    	b1=new Button("确认");
    	add(b1);
    	b1.addActionListener(this);
    	b2=new Button("清除");
    	add(b2);
    	b2.addActionListener(this);
    	
    	text2.setEditable(false);
    }
    public void actionPerformed(ActionEvent e)
    {
    	if(e.getSource()==b1||e.getSource()==text1)
    	{
    		try{
    			weightInEarth.setWeight(Double.valueOf(text1.getText()).doubleValue());
    		    text2.setText(""+weightInEarth.toMoon());
    	    }
    	    catch(NumberFormatException event)
    	    {
    		    text2.setText("请输入数字字符");
    	    }
        }
        else if(e.getSource()==b2)
        {
        	text1.setText("0");
        	text2.setText("");
        }
    }
}
    
    	
    		 
class WeightConvent{
	private double exchangeRate=1.0/6;
    private double weight;
	
	public void setWeight(double weight){
	    this.weight=weight;
	}
	
	public double toMoon(){
		return(weight*exchangeRate);
	}
	public double fromMoon(){
		return(weight/exchangeRate);
	}
}