java计算器程序源代码

Java 計算器源代碼—初級

這是我在04年剛開始接觸java時,跟着一本書學習GUI和事件而寫的,思想還是Vb和Pb的,隻不過是語言不一樣暸.整理以前文件的時候,髮現對于初學者還是有幫助的,就把它放在網上.

這個小程序可是我用記事本和命令行編的,當時侯捷先生的書上建議初學者最簡單的IDE還是這樣的,這對于學Java非常的好.現在在看這個程序對自己的縮進和初步的糢塊設計,還是有些訢慰的.

這是幾個截圖:

启动画面

一些簡單的錯誤處理

一個對話框的幫助文件

我希望如果妳在看這個例子的時候，窗體佈侷，簡單的事件處理，資源文件的定位等方法對妳有所幫助，這裏的所有東西都是簡單的命令行和記事本的成果。

源代碼中，我有暸註釋還是比較詳細的，如果有什么建議或是補充，我真誠的希望妳能提齣來，這樣我纔能夠有所提高，謝謝！！

以下是源碼文件壓縮和jar文檔：

對于jar文檔的執行請妳參攷：Java 程序無Shell調用窗口

由于blog不支持上传压缩文件,我也只能把代码清单贴出来,如果需要压缩的源代码,给我留言。

主文件：

package com.blogchina.qb2049.counter;

import javax.swing.*;

public class CounterDriv

{

public static void main(String[] arg)

{

String str="feiji.gif";

Counter mycounter = new Counter();

SplashWindow wel=new SplashWindow(str,mycounter);

}

}

欢迎界面：

package com.blogchina.qb2049.counter;

//欢迎界面的代码

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import https://www.360docs.net/doc/613462780.html,.URL;

class SplashWindow extends JWindow

{

public SplashWindow(String filename,Frame f)

{

JPanel soth = new JPanel();

JRadioButton quck=new JRadioButton("下次不再显示");

soth.setLayout(new BorderLayout());

JLabel infor=new JLabel("欢迎使用小型计算器",JLabel.CENTER);

JLabel quit =new JLabel("点击鼠标退出",JLabel.RIGHT);

URL icoURL=SplashWindow.class.getResource("/image/"+filenam e);

JLabel welpic =new JLabel (new ImageIcon(icoURL));

getContentPane().add(infor,BorderLayout.NORTH);

getContentPane().add(welpic, BorderLayout.CENTER);

soth.add(quit,BorderLayout.EAST);

soth.add(quck,BorderLayout.WEST);

getContentPane().add(soth,BorderLayout.SOUTH);

//pack()使得Swing把窗口调整到适当的大小

pack();

//显示位置设置

Dimension screenSize = Toolkit.getDefaultToolkit().getScree nSize();

Dimension labelSize=welpic.getPreferredSize();

setLocation((screenSize.width-labelSize.width)/2,(screenSiz e.height- labelSize.height)/2);

//鼠标事件点击退出

addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

setVisible(false);

dispose();

}

});

/*为了解决这个问题，Swing设计者赋予我们安全地把Runnable对象加入UI事件队列的能力。在本例中，

我们用可运行对象closerRunner完成最关键的工作。我们把可运行对象传入 SwingUtilities.invoke AndWait()静态方法，然后wingUtilities.invokeAndWait()进行所有未完成的 UI操作，并执行传递给该方法的可运行对象closerRunner的run方法。通过运用一个独立的线程负责欢

迎屏幕的关闭操作，应用担负起了显示和关闭欢迎屏幕之间的所有操作。*/

//显示停止的时间,运用线程

final int pause=10000;

//线程启动时,关闭界面

final Runnable closeRunner =new Runnable()

{

public void run()

{

setVisible(false);

dispose();

}

};

//线程参数的设置

/* 由于Swing是非线程安全的，除非代码在事件分派线程上执行，否则它就不应该影响任何UI组件的状

态。所谓事件分派线程，就是Swing中负责绘图和事件处理的线程。*/ Runnable waitRunner =new Runnable()

{

public void run()

{

try{

Thread.sleep(pause);

SwingUtilities.invokeAndWait(closeRunner);

}catch(Exception e)

{

e.printStackTrace();

}

}

};

setVisible(true);

//定义线程

Thread splashThread =new Thread(waitRunner,"splashThread"); //启动线程

splashThread.start();

}

}

计算器的界面：

package com.blogchina.qb2049.counter;

//Counter.java

import javax.swing.*;

import javax.swing.event.*;

import java.awt.*;

import java.awt.event.*;

public class Counter extends JFrame implements ActionListener {

Counter frame;

String left="";

String right="";

String mid="";

char flag='\0';

boolean pit=true;

JTextField answer=new JTextField("0.",2);

Container counterpanel=this.getContentPane(); JPanel panel = new JPanel();

JPanel pane=new JPanel();

//面板上的控制按钮

JButton clear = new JButton("CN");

JButton l1=new JButton("1");

JButton l2=new JButton("2");

JButton l3=new JButton("3");

JButton l4=new JButton("4");

JButton l5=new JButton("5");

JButton l6=new JButton("6");

JButton l7=new JButton("7");

JButton l8=new JButton("8");

JButton l9= new JButton("9");

JButton l0= new JButton("0");

JButton sum= new JButton("+");

JButton sub= new JButton("-");

JButton drv=new JButton("÷");

JButton tim=new JButton("×");

JButton sqr=new JButton("SQR");

JButton back=new JButton("←");

JButton point=new JButton(".");

JButton ad=new JButton("=");

JButton cos= new JButton("cos()");

JButton sin =new JButton("sin()");

JMenu jmenufile =new JMenu();

JMenu jmenuhelp = new JMenu();

JMenuBar bar = new JMenuBar();

JMenuItem jmenufile_quit = new JMenuItem();

JMenuItem jmenufile_copy =new JMenuItem();

JMenuItem jmenufile_past =new JMenuItem();

JMenuItem jmenuhelp_help =new JMenuItem();

JMenuItem jmenuhelp_about =new JMenuItem();

public Counter()

{

this.setTitle("小型计算器");

panel.setLayout(new BorderLayout());

pane.setLayout(new GridLayout(5,4));

clear.addActionListener(this);

l1.addActionListener(this);

l2.addActionListener(this);

l3.addActionListener(this);

l4.addActionListener(this);

l5.addActionListener(this);

l6.addActionListener(this);

l7.addActionListener(this);

l8.addActionListener(this);

l9.addActionListener(this);

l0.addActionListener(this);

sum.addActionListener(this);

sub.addActionListener(this);

point.addActionListener(this);

ad.addActionListener(this);

cos.addActionListener(this);

sin.addActionListener(this);

drv.addActionListener(this);

tim.addActionListener(this);

back.addActionListener(this);

sqr.addActionListener(this);

pane.add(l1);

pane.add(l2);

pane.add(l3);

pane.add(sum);

pane.add(l4);

pane.add(l5);

pane.add(l6);

pane.add(sub);

pane.add(l7);

pane.add(l8);

pane.add(l9);

pane.add(tim);

pane.add(l0);

pane.add(point);

pane.add(ad);

pane.add(drv);

pane.add(cos);

pane.add(sin);

pane.add(sqr);

pane.add(back);

panel.add(clear,BorderLayout.NORTH);

panel.add(pane,BorderLayout.CENTER);

answer.setHorizontalAlignment(JTextField.RIGHT );

answer.setColumns(2);

answer.setEditable(false);

answer.setBackground(Color.white);

Font f=new Font(null,Font.BOLD,18);

answer.setFont(f);

counterpanel.add(answer,BorderLayout.NORTH);

counterpanel.add(panel,BorderLayout.CENTER);

this.setSize(300,320);

Dimension framesize = this.getSize();

Dimension screensize=Toolkit.getDefaultToolkit().getScreenSize ();

this.setLocation((screensize.width-framesize.width)/2,(screensi ze.height

- framesize.height)/2);

jmenufile.setText("编辑");

jmenufile_copy.setText("复制");

jmenufile_past.setText("粘贴");

jmenufile_quit.setText("退出");

jmenufile_quit.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e )

{

Counter.this.dispose();

System.exit(0);

}

});

jmenufile.add(jmenufile_copy);

jmenufile.add(jmenufile_past);

jmenufile.add(jmenufile_quit);

jmenuhelp.setText("帮助");

jmenuhelp_help.setText("帮助主题");

jmenuhelp_about.setText("关于本软件");

jmenuhelp_about.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e )

{

Counter_About about =new Counter_About(frame); }

});

jmenuhelp.add(jmenuhelp_help);

jmenuhelp.add(jmenuhelp_about);

bar.add(jmenufile);

bar.add(jmenuhelp);

this.setJMenuBar(bar) ;

WindowListener bw =new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{

Counter.this.dispose();

System.exit(0);

}

};

this.addWindowListener(bw);

this.setVisible(true);

}

//进行算术的运算

public void actionPerformed(ActionEvent e ) {

if(e.getSource()==l1)

{

mid=mid+"1";

answer.setText(mid);

}

if(e.getSource()==l2)

{

mid=mid+"2";

answer.setText(mid);

}

if(e.getSource()==l3)

{

mid=mid+"3";

answer.setText(mid);

}

if(e.getSource()==l4)

{

mid=mid+"4";

answer.setText(mid);

}

if(e.getSource()==l5)

{

mid=mid+"5";

answer.setText(mid);

}

if(e.getSource()==l6)

{

mid=mid+"6";

answer.setText(mid);

}

if(e.getSource()==l7)

{

mid=mid+"7";

answer.setText(mid);

}

if(e.getSource()==l8)

{

mid=mid+"8";

answer.setText(mid);

}

if(e.getSource()==l9)

{

mid=mid+"9";

answer.setText(mid);

}

if(e.getSource()==l0)

{

mid=mid+"0";

answer.setText(mid);

}

if(e.getSource()==point)

{

String chk=answer.getText();

if(!chk.equals("0."))

{

if(pit && answer.getText().length()!=0)

{

mid=mid+".";

answer.setText(mid);

pit=false;

}

}

}

if(e.getSource()==back)

{

if(answer.getText().length()!=0)

{

int len=answer.getText().length();

mid=answer.getText().substring(0,len-1); answer.setText(mid);

}

int g=mid.indexOf(".");

if(g==-1)

{

pit=true;

}

}

if(e.getSource()==clear)

{

mid="";

answer.setText("0.");

}

if(e.getSource()==sum)

{

flag='+';

pit=true;

left=answer.getText();

mid="";

answer.setText("");

}

if(e.getSource()==sub)

{

String chk=answer.getText().trim(); if(chk.equals("")||chk.equals("0.")) {

mid=mid+"-";

answer.setText(mid);

}

else

{

flag='-';

pit=true;

left=answer.getText();

mid="";

answer.setText("");

}

}

if(e.getSource()==tim)

{

flag='×';

pit=true;

left=answer.getText();

mid="";

answer.setText("");

}

if(e.getSource()==drv)

{

flag='÷';

pit=true;

left=answer.getText();

mid="";

answer.setText("");

}

try{

if(e.getSource()==sqr)

{

double res1=0;

if(!answer.getText().equals(""))

{

double sq=Double.parseDouble(answer.getText()); if(sq>=0)

{

res1=Math.sqrt(sq);

answer.setText(String.valueOf(res1));

}

else

{

answer.setText("0");

}

}

}

if(e.getSource()==cos)

{

if(!answer.getText().equals(""))

{

double res2=Math.cos(Double.parseDouble(answer.getTe xt()));

answer.setText(String.valueOf(res2));

}

}

if(e.getSource()==sin)

{

if(!answer.getText().equals(""))

{

double res2=Math.sin(Double.parseDouble(answer.getTe xt()));

answer.setText(String.valueOf(res2));

}

}

}catch(NumberFormatException ex)

{

System.out.println("出现了对非数字计算问题!");

}

if(e.getSource()==ad)

{

double res=0;

mid="";

if(!left.equals("")&&!answer.getText().equals(""))

{

try{

switch(flag)

{

case '+':

right=answer.getText();

res=Double.parseDouble(left) + Double.parseD ouble(right);

answer.setText(String.valueOf(res));

break;

case '-':

right=answer.getText();

res=Double.parseDouble(left) - Double.parseD ouble(right);

answer.setText(String.valueOf(res));

break;

case '×':

right=answer.getText();

res=Double.parseDouble(left) * Double.parseD ouble(right);

answer.setText(String.valueOf(res));

break;

case '÷':

right=answer.getText();

if(Double.parseDouble(right)!=0)

{

res=Double.parseDouble(left) / Double.pars eDouble(right);

answer.setText(String.valueOf(res));

}

else

{

JOptionPane.showMessageDialog(null,"除数

不能为零,请改正!","错误提示",

https://www.360docs.net/doc/613462780.html,RMATION_MESSAGE);

left="";

}

break;

} }catch(NumberFormatException ex)

{

System.out.println("出现了输入的异常"); }

catch(RuntimeException ex)

{

System.out.println("运行过程中出现异常"); }

}

}

}

}

计算器关于对话框：

package com.blogchina.qb2049.counter;

//计算器的关于菜单

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

import https://www.360docs.net/doc/613462780.html,.URL;

public class Counter_About extends JDialog

{

private JLabel ico;

private JLabel tit;

private JLabel con1;

private JLabel con2;

private JLabel con3;

private JLabel con4;

private JLabel con5;

private JPanel upane;

private JPanel botpane;

Counter_About(JFrame frame)

{

//标题显示

super.setTitle("欢迎使用小计算器");

Container pan = this.getContentPane();

String str="counter.gif";

URL icoURL=Counter_About.class.getResource("/image/"+str);

ico=new JLabel(new ImageIcon(icoURL));

tit=new JLabel("欢迎使用本小计算器",JLabel.CENTER);

con1=new JLabel("本小计算器是在JDK1.4.2的基础上,运行与开发出来");

con2=new JLabel("希望本小计算器能给你带来方便");

con3 =new JLabel("本小型计算器如有错误和不足请联系:tiezhou@qgzx https://www.360docs.net/doc/613462780.html,");

con4 =new JLabel("谢谢使用!!",JLabel.CENTER);

con5 =new JLabel("2004年8月",JLabel.RIGHT);

upane =new JPanel();

botpane=new JPanel();

upane.setLayout(new BorderLayout());

botpane.setLayout(new GridLayout(5,1));

try {