计算器实验报告

实验二、巩固Java基础一、实验目的1）巩固Java语言进行结构化程序设计基本概念。

2）巩固Java语言进行面向对象程序设计基本概念。

3）能够应用面向对象程序设计思想解决实际问题。

二、实验内容1）创建学生类Student来完成下面问题。

（1）创建类Student，包括属性学号no、姓名name和年龄age，且都是private 类型；（2）声明一个构造方法，以初始化对象的所有的域；（3）声明获得各属性（学号、姓名和年龄）的各个方法；（4）声明设置各属性（学号、姓名和年龄）的各个方法；（5）声明一个public型的toString方法，将该类所有域信息组合成一个字符串；（6）声明统计创建Student对象的个数的成员变量count和得到Student对象的个数的方法。

在主类中使用Student类创建两个Student对象，输出对象所有域信息；修改其姓名和年龄，并显示。

public class Student {//无参构造函数public Student(){}//有参构造函数public Student(String no, String name, int age){this.no = no;this.age = age; = name;}private String no; //学号private String name;//名称private int age;//年龄public String getNo() {return no;}public void setNo(String no) {this.no = no;}public String getName() {return name;}public void setName(String name) { = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}//-----------------------------Set 跟Get 方法end ------------------//重写toString方法@Overridepublic String toString() {return "我的名字叫：".concat(name).concat("，学号是：").concat(no).concat("，今年").concat(age+"岁了！");}//程序入口public static void main(String[] args) {//学生对象1stu = new Student("00001", "小明", 18);System.out.println(stu.toString());//学生对象2stu = new Student("00002", "小花", 22);System.out.println(stu.toString());}}三、需求分析该计算器程序除了具备加减乘除基本的功能外还有重置功能 ce，程序里面实现了事件监听接口，该程序只能实现一些基本的加减乘除运算。

计算器的基本功能：1、加法运算：用数字按钮和“+”按钮进行运算；2、减法运算：用数字按钮和“-”按钮进行运算；3、乘法运算：用数字按钮和“*”按钮进行运算；4、除法运算：用数字按钮和“/”按钮进行运算；5、开根运算：用数字按钮和“sqrt”按钮进行运算；6、返回上一级键实现；7、清零键C按钮实现。

四、系统设计功能函数说明actionPerformed 将每个组件都添加事件响应。

具体的事件响应操作将在其他的类中逐一实现。

jbInit() 对程序进行初始化并设置大小，名字，布局方式handleReset()类实现C、CE、backspace按钮的复位操作handleNumber() 字符串输入控制类完成简单计算器的设计与实现。

图形界面如下图所示：系统界面如下图所示五、源程序运行正常，可以实现计算器的“+”“—”“*”“/”等运算功能。

/* 一个计算器，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。

*/ package sy;import java.awt.*;import javax.swing.*;import java.awt.event.*;import java.io.*;//创建Calculate类继承swing包里的JFrame类用于显示界面里标签、按钮和文本字段public class Calculate extends JFrame {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//swing包中对窗体中具有相同逻辑功能的组件进行组合的类JPanel contentPane; /** 计算器上的键的显示名字创建对象并实例化*/JTextField txtResult = new JTextField("0");JButton btnNull = new JButton("sqrt");//新建一个按钮显示为sqrtJButton btnFour = new JButton("4");//新建一个按钮显示为4JButton btnFive = new JButton("5");//新建一个按钮显示为5JButton btnSix = new JButton("6");//新建一个按钮显示为6JButton btnDecrease = new JButton("-");//新建一个按钮显示为-JButton btnBegin = new JButton("C");//新建一个按钮显示为cJButton btnOne = new JButton("1");//新建一个按钮显示为1JButton btnTwo = new JButton("2");//新建一个按钮显示为2JButton btnThree = new JButton("3");//新建一个按钮显示为3JButton btnMultiply = new JButton("*");//新建一个按钮显示为*JButton btnCancel = new JButton("←");//新建一个按钮显示为←JButton btnZero = new JButton("0");//新建一个按钮显示为0JButton btnMinus = new JButton("+/-");//新建一个按钮显示为+/-JButton btnPoint = new JButton(".");//新建一个按钮显示为.JButton btnDivide = new JButton("/");//新建一个按钮显示为/JButton btnEqual = new JButton("=");//新建一个按钮显示为=JButton btnIncrease = new JButton("+");//新建一个按钮显示为+JButton btnSeven = new JButton("7");//新建一个按钮显示为7JButton btnEight = new JButton("8");//新建一个按钮显示为8JButton btnNine = new JButton("9");//新建一个按钮显示为9//用try，catch抛出错误，监视所有又可能发生异常的代码public Calculate() {try {setDefaultCloseOperation(EXIT_ON_CLOSE);//用户单击窗口的关闭按钮时程序执行的操作jbInit();} catch (Exception exception) {exception.printStackTrace();} }//建立一个私有的jbinit类对程序进行初始化并设置大小，名字，布局方式private void jbInit() throws Exception {contentPane = (JPanel) getContentPane();contentPane.setLayout(null); //设置布局方式null就是默认为流式布局this.setResizable(false);//窗口大小不可改变setSize(new Dimension(400, 300)); //设置大小位置在屏幕(400, 300)坐标处显示计算setTitle("计算器");//设置标题txtResult.setEnabled(false); // 设置控件是否可用txtResult.setFont(new java.awt.Font("Dialog", Font.PLAIN, 20));txtResult.setEditable(false);// 不允许修改结果文本框txtResult.setHorizontalAlignment(SwingConstants.RIGHT);//文本框内容右对齐txtResult.setBounds(new Rectangle(33, 19, 310, 34));//自己制定位置坐标长宽（33,39）310 34btnNull.setBounds(new Rectangle(298, 70, 46, 37));btnNull.setFont(new java.awt.Font("Dialog", Font.PLAIN, 12));//设置字体//btnNull.addActionListener(newFrameCalculate_btnNull_actionAdapter(t his);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(newCalculate_btnBegin_actionAdapter(t his));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(newCalculate_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的监听事件在进行某一个操作的时候触发某项功能btnZero.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnOne.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnTwo.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnThree.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnFour.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnFive.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnSix.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnSeven.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnEight.addActionListener(newCalculate_btnZero_actionAdapter(this)); btnNine.addActionListener(newCalculate_btnZero_actionAdapter(this));btnMinus.setBounds(new Rectangle(101, 222, 46, 37));btnMinus.setFont(new java.awt.Font("Dialog", Font.PLAIN, 10)); btnMinus.addActionListener(newCalculate_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(newCalculate_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(newCalculate_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(newCalculate_btnIncrease_actionAdapter(this)); btnDecrease.addActionListener(newCalculate_btnIncrease_actionAdapter(this)); btnMultiply.addActionListener(newCalculate_btnIncrease_actionAdapter(this)); btnDivide.addActionListener(newCalculate_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));//存放报表内容的容器contentPane.add(btnFive);contentPane.add(btnSix);contentPane.add(btnDecrease);contentPane.add(btnBegin);contentPane.add(btnOne);contentPane.add(btnTwo);contentPane.add(btnThree);contentPane.add(btnMultiply);contentPane.add(btnCancel);contentPane.add(btnMinus);contentPane.add(btnPoint);contentPane.add(btnDivide);contentPane.add(btnEqual);contentPane.add(btnEight);contentPane.add(btnNine);contentPane.add(btnFour);contentPane.add(btnSeven);contentPane.add(btnIncrease);contentPane.add(btnNull);contentPane.add(txtResult);contentPane.add(btnZero);}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(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();elsefront = 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 (ArithmeticException ce) {txtResult.setText("除数不能为零");} catch (Exception ee) {}if (!flag3)flag3 = true;}public void btnPoint_actionPerformed(ActionEvent e) {int num=txtResult.getText().indexOf(".");if(num<0 && !flag)txtResult.setText(txtResult.getText()+e.getActionCommand());if(flag)flag1=true;}public void btnBegin_actionPerformed(ActionEvent e) {//清零运算符事件处理flag=false;flag1=false;flag2=false;flag3=false;front="";behind="";re="";txtResult.setText("0");}public void btnMinus_actionPerformed(ActionEvent e) {//取反运算符事件处理if(txtResult.getText().equals("0")){//如果文本框内容为0txtResult.setText(txtResult.getText());}else if(txtResult.getText().indexOf("-")>=0){//若文本框中含有负号 String a=txtResult.getText().replaceAll("-","");txtResult.setText(a);}else if(flag){txtResult.setText("0");}else{txtResult.setText("-"+txtResult.getText()) }}public void btnCancel_actionPerformed(ActionEvent e) {//退格事件处理方法String str=txtResult.getText();if(str.length() == 1){//如文本框中只剩下最后一个字符,将文本框内容置为0txtResult.setText("0");}if(str.length()>1){str=str.substring(0,str.length()-1);txtResult.setText(str);} }public static void main(String[] args){Calculate fc = new Calculate();fc.setSize(400,310);fc.setLocation(200,150);fc.setVisible(true);}}class Calculate_btnCancel_actionAdapter implements ActionListener { private Calculate adaptee;Calculate_btnCancel_actionAdapter(Calculate adaptee) {this.adaptee = adaptee;}public void actionPerformed(ActionEvent e) {adaptee.btnCancel_actionPerformed(e);}}class Calculate_btnMinus_actionAdapter implements ActionListener { private Calculate adaptee;Calculate_btnMinus_actionAdapter(Calculate adaptee) {this.adaptee = adaptee;}public void actionPerformed(ActionEvent e) {adaptee.btnMinus_actionPerformed(e);}}class Calculate_btnBegin_actionAdapter implements ActionListener {private Calculate adaptee;Calculate_btnBegin_actionAdapter(Calculate adaptee) {this.adaptee = adaptee;}public void actionPerformed(ActionEvent e) {adaptee.btnBegin_actionPerformed(e);}}class Calculate_btnPoint_actionAdapter implements ActionListener {private Calculate adaptee;Calculate_btnPoint_actionAdapter(Calculate adaptee) {this.adaptee = adaptee;}public void actionPerformed(ActionEvent e) {adaptee.btnPoint_actionPerformed(e);}}class Calculate_btnEqual_actionAdapter implements ActionListener {private Calculate adaptee;Calculate_btnEqual_actionAdapter(Calculate adaptee) {this.adaptee = adaptee;}public void actionPerformed(ActionEvent e) {adaptee.btnEqual_actionPerformed(e);}}class Calculate_btnIncrease_actionAdapter implements ActionListener { private Calculate adaptee;Calculate_btnIncrease_actionAdapter(Calculate adaptee) {this.adaptee = adaptee;}public void actionPerformed(ActionEvent e) {adaptee.btnIncrease_actionPerformed(e);}}class Calculate_btnZero_actionAdapter implements ActionListener {private Calculate adaptee;Calculate_btnZero_actionAdapter(Calculate adaptee) {this.adaptee = adaptee;}public void actionPerformed(ActionEvent e) {adaptee.btnZero_actionPerformed(e);}}六、调试过程中的问题计算器的界面多功能还应该更完善。