java课程设计报告-简单计算器.doc

JAVA课程设计设计期限 2016 年 3 月 20 开始 至 2016 年 6 月 20 结束一、课程设计题目：简单计算器二、课程设计目的：（1）熟悉Java编程环境JDK和NetBeans的安装，配置和使用；（2）掌握JavaApplication的编写及调试；（3）掌握Java图形用户界面的设计及其编程；（4）熟练掌握Java的事件委托处理模型；（5）熟练掌握java.awt包常用类的使用；（6）掌握Java的封装、继承和多态程序设计。三、课程设计内容：利用Java编程技术实现一个简单的计算器，具体要求如下：（1）编写一个JavaApplication，使得程序能提供计算器的一般计算功能，计算器界面如下：（2）使用java.awt.Frame创建一个窗框。（3）为计算器的每个按钮(button)注册监听器。（4）利用FlowLayout、BorderLayout、GridLayout设置容器的布局。（5）利用容器间的嵌套策略来布置整个计算器的界面，充分利用Panel作为中间层容器的优点。以下为选做功能：（6）能够对大整数进行运算；（7）对于带括号的表达式，能够根据优先次序求解表达式的值四、开发工具与平台1.开发工具：Eclipse默认是一个和Jbuilder类似的Java开发工具，但它不仅仅只是Java开发工具，只要装上相应的插件，eclipse也可作为其它语言的开发工具。如C/C+插件(CDT)。2.开发平台：JDK1.5五.设计过程5.1、设计流程1.分析该计算器需要完成的功能。用户能够完成添加括号和负号的四则混合运算,并且计算器能够自动识别运算符的优先级，根据用户输入的运算表达式，自动计算出相应的结果。同时还完成了计算器中C按钮清屏功能和Backspace退格键。2.考虑异常处理。（1）当输入的表达式中出现除零的操作，显示框将显示“除数不能为零”。（2）当输入的表达式错误时，将弹出提示框显示“表达式错误请重新输入”（3）当计算器的显示文本框里为没有输入内容时直接点击等号按钮，将弹出提示框显示“对不起，您没有任何输入，请重新输入：”。（4）当第一次输入乘号键,除号键，右括号，小数点，求余键，等号键，ce键，Backspace键时提示错误。4.考虑数据的处理目标计算表达式通过点击计算器界面上的按钮进行输入，当按下等号之后，计算器通过调用JAVA中script这个包中的相关类和方法来实现数据的处理。5.编码实现计算器的功能。（1）新建相关的文件。（2）引入JAVA中相关的包。（3）新建类Jsq，并继承了类Frame，而且实现了接口ActionListener（4）定义相关的变量，创建相关组件，并对组件的属性进行设置。（5）对所创建的组件进行布局，完成界面的实现。（6）为各个组件添加事件监听器。（7）重写事件接口ActionListener的方法publicvoidactionPerformed(ActionEvente)。（8）为各个组件编写事件代码，完成每个按钮的不同功能。5.2、具体过程（1）声明各个组件及变量： private String front = , behind = ; /分别用于记录加减乘除运算符之前,之后输入的内容 private String op; /用于记录运算符 private String re;/用于存储运算结果的字符串格式 private boolean flag = false; /用于记录是否按下了运算符 private boolean flag1 = false;/用于判断是否输入了点运算符 private double result;/用于存储运算结果 private boolean flag2 = false;/用于判断是否输入了数字 private boolean flag3 = false;/用于判断是否按下了等号运算符 JPanel contentPane; JTextField txtResult = new JTextField(0); JButton btnNull = new JButton(sqrt); JButton btnFour = new JButton(4); JButton btnFive = new JButton(5); JButton btnSix = new JButton(6); JButton btnDecrease = new JButton(-); JButton btnBegin = new JButton(C); JButton btnOne = new JButton(1); JButton btnTwo = new JButton(2); JButton btnThree = new JButton(3); JButton btnMultiply = new JButton(*); JButton btnCancel = new JButton(); JButton btnZero = new JButton(0); JButton btnMinus = new JButton(+/-); JButton btnPoint = new JButton(.); JButton btnDivide = new JButton(/); JButton btnEqual = new JButton(=); JButton btnIncrease = new JButton(+); JButton btnSeven = new JButton(7); JButton btnEight = new JButton(8); JButton btnNine = new JButton(9);（2）设置面板及各个组件的规格大小并注册监听者：private void jbInit() throws Exception contentPane = (JPanel) getContentPane(); contentPane.setLayout(null); this.setResizable(false); setSize(new Dimension(400, 300); setTitle(计算器); txtResult.setEnabled(false); txtResult.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); txtResult.setEditable(false); txtResult.setHorizontalAlignment(SwingConstants.RIGHT); txtResult.setBounds(new Rectangle(33, 19, 310, 34); btnNull.setBounds(new Rectangle(298, 70, 46, 37); btnNull.setFont(new java.awt.Font(Dialog, Font.PLAIN, 12); /btnNull.addActionListener(new FrameCalculate_btnNull_actionAdapter(this); btnFour.setBounds(new Rectangle(33, 120, 46, 37); btnFour.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnFive.setBounds(new Rectangle(101, 120, 46, 37); btnFive.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnSix.setBounds(new Rectangle(167, 119, 46, 37); btnSix.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnDecrease.setBounds(new Rectangle(234, 120, 46, 37); btnDecrease.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnBegin.setBounds(new Rectangle(298, 121, 46, 37); btnBegin.setFont(new java.awt.Font(Dialog, Font.PLAIN, 15); btnBegin.addActionListener(new Calculate_btnBegin_actionAdapter(this); btnOne.setBounds(new Rectangle(33, 172, 46, 37); btnOne.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnTwo.setBounds(new Rectangle(101, 172, 46, 37); btnTwo.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnThree.setBounds(new Rectangle(167, 172, 46, 37); btnThree.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnMultiply.setBounds(new Rectangle(234, 172, 46, 37); btnMultiply.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnCancel.setBounds(new Rectangle(298, 172, 46, 37); btnCancel.setFont(new java.awt.Font(Dialog, Font.PLAIN, 12); btnCancel.addActionListener(new Calculate_btnCancel_actionAdapter(this); btnZero.setBounds(new Rectangle(33, 222, 46, 37); btnZero.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); /加载数字0-9的监听事件 btnZero.addActionListener(new Calculate_btnZero_actionAdapter(this); btnOne.addActionListener(new Calculate_btnZero_actionAdapter(this); btnTwo.addActionListener(new Calculate_btnZero_actionAdapter(this); btnThree.addActionListener(new Calculate_btnZero_actionAdapter(this); btnFour.addActionListener(new Calculate_btnZero_actionAdapter(this); btnFive.addActionListener(new Calculate_btnZero_actionAdapter(this); btnSix.addActionListener(new Calculate_btnZero_actionAdapter(this); btnSeven.addActionListener(new Calculate_btnZero_actionAdapter(this); btnEight.addActionListener(new Calculate_btnZero_actionAdapter(this); btnNine.addActionListener(new Calculate_btnZero_actionAdapter(this); btnMinus.setBounds(new Rectangle(101, 222, 46, 37); btnMinus.setFont(new java.awt.Font(Dialog, Font.PLAIN, 10); btnMinus.addActionListener(new Calculate_btnMinus_actionAdapter(this); btnPoint.setBounds(new Rectangle(167, 222, 46, 37); btnPoint.setFont(new java.awt.Font(Dialog, Font.PLAIN, 30); btnPoint.setHorizontalTextPosition(SwingConstants.CENTER); btnPoint.addActionListener(new Calculate_btnPoint_actionAdapter(this); btnDivide.setBounds(new Rectangle(234, 222, 46, 37); btnDivide.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnEqual.setBounds(new Rectangle(298, 222, 46, 37); btnEqual.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnEqual.addActionListener(new Calculate_btnEqual_actionAdapter(this); btnIncrease.setBounds(new Rectangle(234, 70, 46, 37); btnIncrease.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); /加载加减乘除运算符的监听事件 btnIncrease.addActionListener(new Calculate_btnIncrease_actionAdapter(this); btnDecrease.addActionListener(new Calculate_btnIncrease_actionAdapter(this); btnMultiply.addActionListener(new Calculate_btnIncrease_actionAdapter(this); btnDivide.addActionListener(new Calculate_btnIncrease_actionAdapter(this); btnSeven.setBounds(new Rectangle(33, 70, 46, 37); btnSeven.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnEight.setBounds(new Rectangle(101, 70, 46, 37); btnEight.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20); btnNine.setBounds(new Rectangle(167, 70, 46, 37); btnNine.setFont(new java.awt.Font(Dialog, Font.PLAIN, 20);（3）运算符事件处理public void btnZero_actionPerformed(ActionEvent e) if (flag) /如果刚刚按下了运算符 txtResult.setText(); if (flag1) /判断之前是否输入了点运算符 txtResult.setText(0. + e.getActionCommand(); flag1 = false; else txtResult.setText(e.getActionCommand(); flag2 = true; else int num = txtResult.getText().indexOf(.); if (num 0 & !txtResult.getText().equals(0) txtResult.setText(txtResult.getText() + e.getActionCommand(); else if (num = 0 & txtResult.getText().equals(0) txtResult.setText(0. + e.getActionCommand(); else if (num = 0 & !txtResult.getText().equals(0) txtResult.setText(txtResult.getText() + e.getActionCommand(); flag = false; flag3=false; public void btnIncrease_actionPerformed(ActionEvent e) if(flag3) txtResult.setText(txtResult.getText(); op = e.getActionCommand(); /得到刚刚按下的运算符 front = txtResult.getText(); /记录加减乘除运算符之前输入的内容 else if (flag2) ActionEvent ee = new ActionEvent(qq, 1, pp); btnEqual_actionPerformed(ee); op = e.getActionCommand(); /得到刚刚按下的运算符 front = re; flag2 = false; else front = txtResult.getText(); /记录加减乘除运算符之前输入的内容 op = e.getActionCommand(); /得到刚刚按下的运算符 flag3=false; flag = true; /记录已经按下了加减乘除运算符的其中一个 public void btnEqual_actionPerformed(ActionEvent e) if(!flag3)/未曾按下等于运算符 behind = txtResult.getText(); else front = re; try double a1 = Double.parseDouble(front); double b1 = Double.parseDouble(behind); if (op = +) result = a1 + b1; else if (op = -) result = a1 - b1; else if (op = *) result = a1 * b1; else result = a1 / b1; Double r = new Double(result); re = r.toString(result); txtResult.setText(re); catch (Arith