由Java编写的计算器具备实现加减乘除的功能

java编写的计算器，能实现加减乘除。 //***该梦幻计算器与Windows附件自带计算器的标准版功能、界面相仿***// //******但还不支持键盘操作,如有需要，下一次等级将满足你**********// import java.awt.*; import java.lang.*; import javax.swing.*; import javax.swing.event.*; import java.awt.event.*; import java.awt.Component.*; import java.awt.color.*; import java.text.DecimalFormat; //*****************************************************************************// //*****************************************************************************// public class Calculator implements ActionListener //导入动作监听接口 { //******************************// //*****设计计算器界面的单位*****// JFrame frame; //定义框架 JTextField textAnswer; //定义输出显示框 JPanel panel, panel1, panel2, panel3;//定义面板作为子容器，从而达到要求的界面效果 JMenuBar mainMenu; JTextField textMemory; JLabel labelMemSpace; //labelMemSpace单纯做摆设，控制面板的形状 JButton buttonBk, buttonCe, buttonC; JButton button[]; JButton buttonMC, buttonMR, buttonMS, buttonMAdd; JButton buttonDot, buttonAddAndSub, buttonAdd, buttonSub, buttonMul,buttonDiv, buttonMod; JButton buttonSqrt, buttonDao, buttonEqual; JMenu editMenu, viewMenu, helpMenu; JMenuItem copyItem, pasteItem, tItem, sItem, numberGroup, topHelp, aboutCal,myCollege; DecimalFormat df; //设置数据输出精度 boolean clickable; //控制当前能否按键 double memoryd; //使用内存中存储的数字 int memoryi; double vard, answerd; //用来保存double型数据的中间值(vard)和最后结果(answerd) short key = -1, prekey = -1; //key用来保存当前进行何种运算,prekey用来保存前次进行何种运算 boolean clear = false; String copy; //做复制用 JTextArea help; //帮助 JScrollPane scrollHelp; static boolean One =true; //******************// //*****构造函数开始*****// public Calculator() { clickable = true; answerd = 0; frame = new JFrame("梦幻计算器--SWE08008"); frame.setResizable(false);//不允许改变计算器的大小 frame.setLocation(250,150);//设置计算器的起始位置 frame.setBackground(Color.YELLOW); df = new DecimalFormat("0.##############"); //设置数据输出精度(对于double型值) textAnswer = new JTextField("0"); textAnswer.setHorizontalAlignment(JTextField.RIGHT);//设置使数字居右 textAnswer.setText("0"); //textAnswer.setBackground(Color.pink);//设置输出显示框的背景颜色 textAnswer.setSelectionColor(Color.white);//设置选择部分的颜色 textAnswer.setEditable(false); //把输出显示框定义为不可写 textAnswer.setBackground(new Color(182,174,174)); //设置输出显示框的背景颜色 panel = new JPanel(); frame.getContentPane().add(panel); panel1 = new JPanel(); panel2 = new JPanel(); panel.setLayout(new BorderLayout()); //***设计整个面板*** //*********将所有行为与监听绑定********** //*设置菜单* mainMenu = new JMenuBar(); editMenu = new JMenu("编辑(E)"); viewMenu = new JMenu("查看(V)"); helpMenu = new JMenu("帮助(H)"); //***编辑 copyItem = new JMenuItem(" 复制(C) Ctrl+C"); copyItem.addActionListener(this); pasteItem = new JMenuItem(" 粘贴(V) Ctrl+V"); pasteItem.addActionListener(this); editMenu.add(copyItem); editMenu.add(pasteItem); //***查看 tItem = new JMenuItem(" 标准型(T)"); tItem.addActionListener(this); sItem = new JMenuItem(" 科学型(S)"); sItem.addActionListener(this); numberGroup = new JMenuItem(" 数字分组(I)"); numberGroup.addActionListener(this); viewMenu.add(tItem); viewMenu.add(sItem); viewMenu.add(numberGroup); //***帮助 topHelp = new JMenuItem(" 帮助主题(H)"); topHelp.addActionListener(this); help = new JTextArea(10, 30); scrollHelp = new JScrollPane(help); help.setEditable(false); //把输出显示框定义为不可写 help.setBackground(Color.GRAY); help.setSelectedTextColor(Color.white); //设置topHelp的显示内容 help.append("如何执行简单的运算?\n"); help.append("基本步骤:\n"); help.append("1. 键入计算的第一个数字。\n"); help.append("2. 单击 + 执行加; - 执行减、* 执行乘、/执行除。\n"); help.append("3. 键入计算的下一个数字。\n"); help.append("4. 输入所有剩余的运算符和数字。\n"); help.append("5. 单击“=”。\n"); aboutCal = new JMenuItem(" 关于计算器(A)"); aboutCal.setForeground(Color.MAGENTA); aboutCal.addActionListener(this); myCollege =new JMenuItem(" 进入我的学院(W)"); myCollege.addActionListener(this); helpMenu.add(topHelp); helpMenu.add(aboutCal); helpMenu.add(myCollege); //主菜单条 mainMenu.add(editMenu); mainMenu.add(viewMenu); mainMenu.add(helpMenu); //把mainMenu、textAnswer、panel1都放进panel容器中，用BorderLayout布局管理器管理 panel.add(mainMenu, BorderLayout.NORTH); panel.add(textAnswer, BorderLayout.CENTER); panel.add(panel1, BorderLayout.SOUTH); panel1.setLayout(new BorderLayout()); textMemory = new JTextField(3); textMemory.setEditable(false); textMemory.setBackground(new Color(217, 217, 217)); labelMemSpace = new JLabel(" "); //*添加计算器界面上的按钮* //Backspace CE C buttonBk = new JButton("Backspace"); buttonBk.setForeground(new Color(255, 0, 0)); buttonCe = new JButton("CE"); buttonCe.setForeground(new Color(255, 0, 0)); buttonC = new JButton("C"); buttonC.setForeground(new Color(255, 0, 0)); buttonBk.addActionListener(this); buttonCe.addActionListener(this); buttonC.addActionListener(this); panel1.add(panel2, BorderLayout.NORTH); //把panel2放到panel1中，用BorderLayout管理器管理 panel2.setLayout(new FlowLayout(FlowLayout.RIGHT)); panel2.add(textMemory); panel2.add(labelMemSpace); panel2.add(buttonBk); panel2.add(buttonCe); panel2.add(buttonC); panel3 = new JPanel(); panel1.add(panel3, BorderLayout.CENTER); //把panel3放到panel1中，用BorderLayout管理器管理 button = new JButton[10]; for (int i = 0; i < button.length; i++) { button[i] = new JButton(Integer.toString(i)); button[i].setForeground(new Color(0,0,255)); } //MC MR MS M+ buttonMC = new JButton("MC"); buttonMC.setForeground(new Color(0, 0, 0)); buttonMR = new JButton("MR"); buttonMR.setForeground(new Color(0, 0, 0)); buttonMS = new JButton("MS"); buttonMS.setForeground(new Color(0, 0, 0)); buttonMAdd = new JButton("M+"); buttonMAdd.setForeground(new Color(0, 0, 0)); //. + - * / = buttonDot = new JButton("."); buttonDot.setForeground(new Color(0, 0, 0)); buttonAdd = new JButton("+"); buttonAdd.setForeground(new Color(10,224,5)); buttonSub = new JButton("-"); buttonSub.setForeground(new Color(10,224,5)); buttonMul = new JButton("*"); buttonMul.setForeground(new Color(10,224,5)); buttonDiv = new JButton("/"); buttonDiv.setForeground(new Color(10,224,5)); buttonEqual = new JButton("="); buttonEqual.setForeground(new Color(10,224,5)); //sqrt % 1/x +/- buttonSqrt = new JButton("sqrt"); buttonSqrt.setForeground(new Color(224,11,161)); buttonMod = new JButton("%"); buttonMod.setForeground(new Color(224,11,161)); buttonDao = new JButton("1/x"); buttonDao.setForeground(new Color(224,11,161)); buttonAddAndSub = new JButton("+/-"); buttonAddAndSub.setForeground(new Color(224,11,161)); //*用setLayout管理器对panel3按钮进行管理,将所有行为与监听绑定 panel3.setLayout(new GridLayout(4, 6)); panel3.add(buttonMC); buttonMC.addActionListener(this); panel3.add(button[7]); button[7].addActionListener(this); panel3.add(button[8]); button[8].addActionListener(this); panel3.add(button[9]); button[9].addActionListener(this); panel3.add(buttonDiv); buttonDiv.addActionListener(this); panel3.add(buttonSqrt); buttonSqrt.addActionListener(this); panel3.add(buttonMR); buttonMR.addActionListener(this); panel3.add(button[4]); button[4].addActionListener(this); panel3.add(button[5]); button[5].addActionListener(this); panel3.add(button[6]); button[6].addActionListener(this); panel3.add(buttonMul); buttonMul.addActionListener(this); panel3.add(buttonMod); buttonMod.addActionListener(this); panel3.add(buttonMS); buttonMS.addActionListener(this); panel3.add(button[1]); button[1].addActionListener(this); panel3.add(button[2]); button[2].addActionListener(this); panel3.add(button[3]); button[3].addActionListener(this); panel3.add(buttonSub); buttonSub.addActionListener(this); panel3.add(buttonDao); buttonDao.addActionListener(this); panel3.add(buttonMAdd); buttonMAdd.addActionListener(this); panel3.add(button[0]); button[0].addActionListener(this); panel3.add(buttonAddAndSub); buttonAddAndSub.addActionListener(this); panel3.add(buttonDot); buttonDot.addActionListener(this); panel3.add(buttonAdd); buttonAdd.addActionListener(this); panel3.add(buttonEqual); buttonEqual.addActionListener(this); frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE); frame.pack(); frame.show(); }//*****构造函数结束*****// //设置各个按钮行为 public void actionPerformed(ActionEvent event) { boolean sign = false; //判断是否是double型数参与运算，是为true，不是为false Object temp = event.getSource(); //*********************************// //*****监控可能出现异常的按钮******// //***********try开始***************// try { //o***如果按下数据按钮，将按下的按钮代表的数据插入到当前文本框字符串之后 for (int i = 0; i <= 9; i++) { if (temp == button[i] && clickable == true) { if((clear==true)||(textAnswer.getText().equals("0"))) { textAnswer.setText(Integer.toString(i)); if(clear==true) { clear=false; } } else { textAnswer.setText(textAnswer.getText() + Integer.toString(i)); } } } //o***按下'.'按钮时，判断当前文本框内字符串中含不含'.'，如果已含，则不允许再插入'.' if (temp == buttonDot && clickable == true) { boolean isDot = false; for (int i = 0; i < textAnswer.getText().length(); i++) { if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } } if (isDot == false) textAnswer.setText(textAnswer.getText() + "."); } //M***如果按下"+"、"-"、"*"、"/""=" if(true) { //o***如果按下"+"、"-"、"*"、"/" if ( (temp == buttonAdd || temp == buttonSub || temp == buttonMul ||temp == buttonDiv) && clickable == true) { if(One==false) { System.out.println("请输入第二个操作数："); One=true; } if(clear==false) { clear=true; //'+'操作 if (temp == buttonAdd) { switch (prekey) //prekey用来保存前次进行何种运算 { case 0: answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 1: answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 2: answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 3: if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("操作非法----除数不能为零!"); System.out.println("操作非法----除数不能为零!---按C重新开始；按CE继续之前操作！"); clickable = false; } else { answerd /= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } break; default:answerd = Double.parseDouble(textAnswer.getText()); } prekey = key = 0; } //'-'操作 if (temp == buttonSub) { switch (prekey) //prekey用来保存前次进行何种运算 { case 0: answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 1: answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 2: answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 3: if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("操作非法----除数不能为零!"); System.out.println("操作非法----除数不能为零!---按C重新开始；按CE继续之前操作！"); clickable = false; } else { answerd /= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } break; default:answerd = Double.parseDouble(textAnswer.getText()); } prekey = key = 1; } //'*'操作 if (temp == buttonMul) { switch (prekey) //prekey用来保存前次进行何种运算 { case 0:answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 1:answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 2:answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 3:if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("操作非法----除数不能为零!"); System.out.println("操作非法----除数不能为零!---按C重新开始；按CE继续之前操作！"); clickable = false; } else { answerd /= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } break; default:answerd = Double.parseDouble(textAnswer.getText()); } prekey = key = 2; } //'/'操作 if (temp == buttonDiv) { switch (prekey) //prekey用来保存前次进行何种运算 { case 0:answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 1:answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 2:answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); break; case 3:if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("操作非法----除数不能为零!"); System.out.println("操作非法----除数不能为零!---按C重新开始；按CE继续之前操作！"); clickable = false; } else { answerd /= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } break; default:answerd = Double.parseDouble(textAnswer.getText()); } prekey = key = 3; } } } //o***如果按下"="键 //'='操作 if (temp == buttonEqual && clickable == true) { //如果连续按'=',则进行连续运算 if (prekey == 5) //prekey用来保存前次进行何种运算 { if (key == 0) //key用来保存当前进行何种运算 { //(vard)用来保存double型数据的中间值;(answerd)用来保存double型数据的最后结果 answerd += vard; textAnswer.setText(df.format(answerd)); } if (key == 1) { answerd -= vard; textAnswer.setText(df.format(answerd)); } if (key == 2) { answerd *= vard; textAnswer.setText(df.format(answerd)); } if (key == 3) { if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("操作非法----除数不能为零!"); System.out.println("操作非法----除数不能为零!---按C重新开始；按CE继续之前操作！"); clickable = false; } else { answerd /= vard; textAnswer.setText(df.format(answerd)); } } } else { vard = Double.parseDouble(textAnswer.getText()); if (key == 0) { prekey = -1; answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } if (key == 1) { prekey = -1; answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } if (key == 2) { prekey = -1; answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } if (key == 3) { prekey = -1; if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("除数不能为零"); System.out.println("操作非法----除数不能为零!---按C重新开始；按CE继续之前操作！"); clickable = false; } else { answerd /= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } } } prekey = 5; } } //M如果按下'%''sqrt''1/x''-/+' if(true) { //o'%'操作，对第二个操作数除以100 if (temp == buttonMod && clickable == true) { if (answerd == 0) { String s = textAnswer.getText(); textAnswer.setText(s); } else { boolean isDot = false; for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } //如果是double数，除100 if (isDot == true) { double dtemp = Double.parseDouble(textAnswer.getText()); dtemp = dtemp / 100.0; textAnswer.setText(Double.toString(dtemp)); } else { //如果是int数但能被100整除，则去掉末尾两个零 if (Integer.parseInt(textAnswer.getText()) % 100 == 0) { int itemp = Integer.parseInt(textAnswer.getText()); itemp /= 100; textAnswer.setText(Integer.toString(itemp)); } //如果是int数，但不能被100整除，则按double数处理 else { double dtemp = Double.parseDouble(textAnswer.getText()); dtemp = dtemp / 100.0; textAnswer.setText(Double.toString(dtemp)); } } } } //o开根号运算 if (temp == buttonSqrt && clickable == true) { String s = textAnswer.getText(); if (s.charAt(0) == '-') { textAnswer.setText("负数不能开根号"); System.out.println("操作非法----负数不能开根号!---按C重新开始；按CE继续之前操作！"); clickable = false; } else textAnswer.setText(Double.toString(java.lang.Math.sqrt(Double.parseDouble(textAnswer.getText())))); } //o倒数运算 if (temp == buttonDao && clickable == true) { if (textAnswer.getText().charAt(0) == '0' && textAnswer.getText().length() == 1) { textAnswer.setText("零不能求倒数"); System.out.println("操作非法----零不能求倒数!---按C重新开始；按CE继续之前操作！"); clickable = false; } else { boolean isDec = true; int i, j, k; String s = Double.toString(1 / Double.parseDouble(textAnswer.getText())); for (i = 0; i < s.length(); i++) if (s.charAt(i) == '.') break; for (j = i + 1; j < s.length(); j++) if (s.charAt(j) != '0') { isDec = false; break; } if (isDec == true) { String stemp = ""; for (k = 0; k < i; k++) stemp += s.charAt(k); textAnswer.setText(stemp); } else textAnswer.setText(s); } } //按下'+/-'按钮时处理 if (temp == buttonAddAndSub && clickable == true) { boolean isNumber = true; String s = textAnswer.getText(); for (int i = 0; i < s.length(); i++) if (! (s.charAt(i) >= '0' && s.charAt(i) <= '9' || s.charAt(i) == '.' ||s.charAt(i) == '-')) { isNumber = false; break; } if (isNumber == true) { //如果当前字符串首字母有'-'号,代表现在是个负数,再按下时,则将首符号去掉 if (s.charAt(0) == '-') { textAnswer.setText(""); for (int i = 1; i < s.length(); i++) { char a = s.charAt(i); textAnswer.setText(textAnswer.getText() + a); } } //如果当前字符串第一个字符不是符号，则添加一个符号在首字母处 else textAnswer.setText('-' + s); } } } //***计算器有关内存操作***// //****'MC''MS''MR''M+'事件**** if(true) { //'MC'的操作，将内存清0 if (temp == buttonMC && clickable == true) { memoryd = memoryi = 0; textMemory.setText(""); } //'MS'的操作，将当前文本框内容保存入内存，显示'M' if (temp == buttonMS && clickable == true) { boolean isDot = false; textMemory.setText(" M"); for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } //如果是double,则存入memoryd(double存储器) if (isDot == true) { memoryd = Double.parseDouble(textAnswer.getText()); memoryi = 0; //保证存储器中存放最新的值 } //如果是int,则存入memoryi(int存储器) else { memoryi = Integer.parseInt(textAnswer.getText()); memoryd = 0; //保证存储器中存放最新的值 } } //'MR'的操作，将存储器中的信息输出 if (temp == buttonMR && clickable == true) { if (memoryd != 0) textAnswer.setText(Double.toString(memoryd)); if (memoryi != 0) textAnswer.setText(Integer.toString(memoryi)); } //'M+'的功能，将当前文本框里的数据和存储器中数据相加后，再存入存储器 if (temp == buttonMAdd && clickable == true) { boolean isDot = false; for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } if (memoryi != 0) { //存储中是一个int型数 if (isDot == false) //被加数是一个int型数 memoryi += Integer.parseInt(textAnswer.getText()); else { //被加数是一个double型数，则将int存储器中数传入double存储器与当前数相加，int存储器清零 memoryd = memoryi + Double.parseDouble(textAnswer.getText()); memoryi = 0; } } else memoryd += Double.parseDouble(textAnswer.getText()); } } //****'Backspace''CE''C'事件**** if(true) { //按下'Backspace'键，利用循环将当前字符串中的最后一个字母删除 if (temp == buttonBk && clickable == true) { String s = textAnswer.getText(); textAnswer.setText(""); for (int i = 0; i < s.length() - 1; i++) { char a = s.charAt(i); textAnswer.setText(textAnswer.getText() + a); } } //按下'CE'按钮，将当前文本框内数据清除 if (temp == buttonCe) { textAnswer.setForeground(Color.BLACK); textAnswer.setText("0"); clickable = true; clear=false; } //按下'C'按钮，文本框内数据清除，同时var,answer清0 if (temp == buttonC) { if(true) { System.out.println("请输入第一个操作数："); One=false; } textAnswer.setForeground(Color.BLACK); vard = answerd = 0; textAnswer.setText("0"); clickable = true; clear=false; key = -1; prekey = -1; } } //****菜单栏事件**** if(true) { //按下'复制'菜单栏 if (temp == copyItem) { copy = textAnswer.getText(); } //按下'粘贴'菜单栏 if (temp == pasteItem) { textAnswer.setText(copy); } //按下'标准型'菜单栏 if (temp == tItem) { //无变化 } //按下'科学型'菜单栏 if (temp == sItem) { JOptionPane.showMessageDialog(panel, "当前是标准型梦幻计算器!\n科学型计算器暂时无此功能，期待下一次的升级吧!\n谢谢使用！"); } //按下'数字分组'菜单栏 if (temp == numberGroup) { JOptionPane.showMessageDialog(panel, "梦幻计算器暂时无此功能，期待下一次的升级吧!\n谢谢使用！"); } //按下'帮助主题'菜单栏 if (temp == topHelp) { JOptionPane.showMessageDialog(panel, scrollHelp,"帮助主题",JOptionPane.INFORMATION_MESSAGE); } //按下'关于'菜单栏 if (temp == aboutCal) { JOptionPane.showMessageDialog(panel, "计算器梦幻版！\n欢迎试用，发现错误请指教！\n开发者:洪成果\n学号:SWE08008","关于计算器",JOptionPane.INFORMATION_MESSAGE); } //按下'进入我的学院'菜单栏 if (temp == myCollege) { Process p = Runtime.getRuntime().exec("explorer http://www.jgxy.xmu.edu.cn/index.php"); } } }//try结束 //*******捕获异常:输入中如果有操作非法，比如连续按下两次"+"、"-"、"*"、"/"********// catch (Exception e) { textAnswer.setForeground(Color.green); textAnswer.setText("系统提示：操作非法-------按C重新开始；按CE继续之前操作！"); System.out.println("系统提示：操作非法-------按C重新开始；按CE继续之前操作！"); clickable = false; } //********************************************************************************// } //*********主函数************ public static void main(String args[]) { if(true) { System.out.println("请输入第一个操作数："); One=false; } //将计算器实例化"梦幻计算器" Calculator MHJSQ=new Calculator(); } }