interest.java

还不错的java基本实例

/*
 * 创建日期 2006-1-26
 *
 * TODO 要更改此生成的文件的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
package ch4;

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.text.NumberFormat;
public class Interest extends JFrame{
   private JLabel amountLabel;
   private JLabel annualRateLabel;
   private JLabel periodLabel;
   private JTextField amountText;
   private JTextField annualRateText;
   private JTextField periodText;   
 private JTextArea text1;   
    private JButton btnShow;
    private JButton btnClear;
    private JButton btnClearInputField;

    public Interest() {
        createComponents();
        registerEventHandlers();
        layoutComponents();
         setTitle("复利存款应用程序");
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         pack();
    }

     private void createComponents() {  //组件实例化
      amountLabel=new JLabel("本金");
      annualRateLabel=new JLabel("年利率");
      periodLabel=new JLabel("年   数");
      amountText=new JTextField(10);
        annualRateText=new JTextField(10);
        periodText=new JTextField(10);
               text1 = new JTextArea();            
              
               btnClear=new JButton("清除");
               btnShow = new JButton("计算");
             
     }

     private void registerEventHandlers() {  //注册事件
          btnShowActionEventHander hander1=new btnShowActionEventHander();
          btnShow.addActionListener(hander1);
      
          btnClearActionEventHander hander2=new btnClearActionEventHander();
          btnClear.addActionListener(hander2);
     }

     private void layoutComponents() {  //布局
         Container c=this.getContentPane();
         c.setLayout(new FlowLayout());
        //存放文本框和标签
        JPanel loanAmountPane = new JPanel();
        loanAmountPane.add(amountLabel);
        loanAmountPane.add(amountText);
        //存放文本框和标签
        JPanel annualRatePane = new JPanel();
        annualRatePane.add(annualRateLabel);
        annualRatePane.add(annualRateText);
        //存放文本框和标签
        JPanel loanPeriodPane = new JPanel();
        loanPeriodPane.add(periodLabel);
        loanPeriodPane.add(periodText);
        
        //存放按钮
        JPanel buttonPane = new JPanel();
         buttonPane.add(btnShow);       
         buttonPane.add(btnClear);
        
        
        //存放文本框和按钮
        JPanel leftPane = new JPanel(new GridLayout(4,1));
        leftPane.add(loanAmountPane);
        leftPane.add(annualRatePane);
        leftPane.add(loanPeriodPane);
        leftPane.add(buttonPane);
     
        JScrollPane scrollPane=new JScrollPane(text1);
        scrollPane.setPreferredSize(new Dimension(200,150));
      
        c.add(leftPane);
        c.add(scrollPane);         
    }

      private class btnShowActionEventHander implements ActionListener{
        public void actionPerformed(ActionEvent e) {        
            double amount , principal ;
			double rate ;
			int n ;			
			String output  = "年" + "\t"+ "复利存款" + "\n";
			int year  = 1;
			NumberFormat currencyformatter=NumberFormat.getCurrencyInstance();
			principal = Double.parseDouble(amountText.getText());
			rate =Double.parseDouble(annualRateText.getText());
			n = Integer.parseInt(periodText.getText());
			
			 do{
			    amount = principal * Math.pow(1 + rate, year);
				output += year +"\t" + currencyformatter.format(amount)+ "\n";
				year = year + 1;
			}while(year <= n);
			text1.setText(output);
		} 
    }
      private class btnClearActionEventHander implements ActionListener{
        public void actionPerformed(ActionEvent e) {
         amountText.setText("");
            annualRateText.setText("");
            periodText.setText("");
            text1.setText("");
        }
    }
    
    public static void main(String[] args) {
        JFrame.setDefaultLookAndFeelDecorated(true);
        Interest frame=new Interest();
        frame.setVisible(true);
       }
    
}