Java实训作业题目：Java实现简易计算器学院：姓名：学号：班级：20 年月一、实验目的通过课程设计，主要要达到两个目的，一是检验和巩固专业知识、二是提高综合素质和能力。

此次课程设计实训主要是Java语言程序设计的实现。

通过该课程设计，可以将课堂上掌握的理论知识与处理数据的业务相结合，以检验自己掌握知识的宽度、深度及对知识的综合运用能力。

二、实验要求用Java编写一个简单的计算器，使其能够实现最基本的功能，如简单的加、减、乘、除；平方根，倒数，平方等功能。

三、详细内容1.界面设计界面设计使用GUI，其中有用到swing组件的TextField和Button，用到awt中的BorderLayout和GridLayout布局管理方式，其图形界面如图1-1所示：图1-1其中主要代码为：public mainWindow(){this.setTitle("计算器");//用户图形界面标题this.setVisible(true);//用户图形界面可缩小this.setResizable(false);//用户图形界面不可放大this.setSize(350,300);//设置用户图形界面的大小this.setLocation(400,150);//用户图形界面在屏幕中的显示位置JPanel panel1 = new JPanel();//新建一个画板JPanel panel2 = new JPanel();button1 = new JButton("1");...reset = new JButton("CE");Container container = this.getContentPane();container.add(panel2,BorderLayout.NORTH);container.add(panel1);panel1.setLayout(new GridLayout(5,4));//将画板1分为4行5列result.setEnabled(false);result.setFont(new Font("Dialog",Font.BOLD,25));//运算结果的字体大小result.setEditable(false);result.setHorizontalAlignment(SwingConstants.RIGHT);panel1.add(reciprocal);//分别将20个按钮依次添加到画板panel1中，并设置各自的大小reciprocal.setFont(new Font("Dialog",Font.PLAIN,20));...panel1.add(divide);divide.setFont(new Font("Dialog",Font.PLAIN,20));panel2.setLayout(new GridLayout());panel2.add(result);//画板panel2添加运算结果2.四则运算较为简单的实现了简单的加、减、乘、除运算，主要代码如下：ActionListener equal1 = new ActionListener(){ //实现四则运算public void actionPerformed(ActionEvent e){String str = result.getText();b = DatatypeConverter.parseDouble(str);{if(flag == "+")c = a + b;else if(flag == "-")c = a - b;else if(flag == "*")c = a * b;else if(flag == "/" || b != 0)c = a / b;}if(flag != "=")result.setText("" + c);elseresult.setText("零不能做除数！");a = 0;b = 0;c = 0;flag = "";}};3.其他功能另外添加了平方根，倒数，平方等功能，主要代码如下：平方根运算的实现：ActionListener sqrt1= new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = Math.sqrt(i);result.setText("" + i);}};倒数运算的实现：ActionListener reciprocal1 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = 1/i;result.setText("" + i);}};平方运算的实现：ActionListener square1 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = i*i;result.setText("" + i);}};4.程序测试经测试发现本计算器基本功能均能实现，可正常运行计算，针对功能实现的代码部分过于简单，可以对其进行改善提高，方便用户使用！5.实训小结通过对计算器窗体的编写，熟悉了java图形用户界面的设计原理和程序结构，熟悉了java中awt和swing的组合。

学会将书本上的知识运用在实际中，提升了编程能力。

四、源代码import java.awt.BorderLayout;import java.awt.Color;import java.awt.Container;import java.awt.Font;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.JTextField;import javax.swing.SwingConstants;import javax.xml.bind.DatatypeConverter;public class Calculator{public static void main(String[] args){new mainWindow();//新建主类调用}}class mainWindow extends JFrame{JTextField result = new JTextField("0");//结果栏用于存储运算结果JButton button0;//按钮0JButton button1;//按钮1JButton button2;//按钮2JButton button3;//按钮3JButton button4;//按钮4JButton button5;//按钮5JButton button6;//按钮6JButton button7;//按钮7JButton button8;//按钮8JButton button9;//按钮9JButton reciprocal;//倒数按钮JButton square;//平方按钮JButton sqrt;//平方根按钮JButton reset;//清零按钮JButton add;//加法按钮JButton reduce;//减法按钮JButton multiply;//乘法按钮JButton divide;//除法按钮JButton equal;//等号按钮JButton point;//小数点按钮double a,b,c;String flag;public mainWindow(){this.setTitle("计算器");//用户图形界面标题this.setVisible(true);//用户图形界面可缩小this.setResizable(false);//用户图形界面不可放大this.setSize(350,300);//设置用户图形界面的大小this.setLocation(400,150);//用户图形界面在屏幕中的显示位置JPanel panel1 = new JPanel();//新建一个画板JPanel panel2 = new JPanel();button1 = new JButton("1");button2 = new JButton("2");button3 = new JButton("3");button4 = new JButton("4");button5 = new JButton("5");button6 = new JButton("6");button7 = new JButton("7");button8 = new JButton("8");button9 = new JButton("9");button0 = new JButton("0");reciprocal = new JButton("1/X");square = new JButton("X^2");sqrt = new JButton("√￣");add = new JButton("+");reduce = new JButton("-");multiply = new JButton("*");divide = new JButton("/");equal = new JButton("=");point = new JButton(".");reset = new JButton("CE");Container container = this.getContentPane();container.add(panel2,BorderLayout.NORTH);container.add(panel1);panel1.setLayout(new GridLayout(5,4));//将画板1分为4行5列result.setEnabled(false);result.setFont(new Font("Dialog",Font.BOLD,25));//运算结果的字体大小result.setEditable(false);result.setHorizontalAlignment(SwingConstants.RIGHT);panel1.add(reciprocal);//分别将20个按钮依次添加到画板panel1中，并设置各自的大小reciprocal.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(square);square.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(sqrt);sqrt.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(reset);reset.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(button7);button1.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(button8);button2.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(button9);button3.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(add);add.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(button4);button4.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(button5);button5.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(button6);button6.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(reduce);reduce.setFont(new Font("Dialog",Font.PLAIN,25)); panel1.add(button1);button7.setFont(new Font("Dialog",Font.PLAIN,20)); panel1.add(button2);button8.setFont(new Font("Dialog",Font.PLAIN,20)); panel1.add(button3);button9.setFont(new Font("Dialog",Font.PLAIN,20)); panel1.add(multiply);multiply.setFont(new Font("Dialog",Font.PLAIN,20)); panel1.add(button0);button0.setFont(new Font("Dialog",Font.PLAIN,20)); panel1.add(point);point.setFont(new Font("Dialog",Font.PLAIN,20));panel1.add(equal);equal.setFont(new Font("Dialog",Font.PLAIN,25)); equal.setForeground(Color.red);//将等号设置为红色panel1.add(divide);divide.setFont(new Font("Dialog",Font.PLAIN,20));panel2.setLayout(new GridLayout());panel2.add(result);//画板panel2添加运算结果button0.addActionListener(al0);//设置20个按钮的监听事件button1.addActionListener(al1);button2.addActionListener(al2);button3.addActionListener(al3);button4.addActionListener(al4);button5.addActionListener(al5);button6.addActionListener(al6);button7.addActionListener(al7);button8.addActionListener(al8);button9.addActionListener(al9);reciprocal.addActionListener(reciprocal1);square.addActionListener(square1);sqrt.addActionListener(sqrt1);reset.addActionListener(reset1);add.addActionListener(add1);point.addActionListener(point1);multiply.addActionListener(multiply1);divide.addActionListener(divide1);equal.addActionListener(equal1);reduce.addActionListener(reduce1);}ActionListener al0 = new ActionListener(){ //各个按钮的监听事件实现运算public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "0");}};ActionListener al1 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "1");}};ActionListener al2 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "2");}};ActionListener al3 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "3");}};ActionListener al4 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "4");}};ActionListener al5 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "5");}};ActionListener al6 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "6");}};ActionListener al7 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "7");}};ActionListener al8 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "8");}};ActionListener al9 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + "9");}};ActionListener sqrt1= new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = Math.sqrt(i);result.setText("" + i);}};ActionListener reciprocal1 = new ActionListener(){ public void actionPerformed(ActionEvent e){String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = 1/i;result.setText("" + i);}};ActionListener square1 = new ActionListener(){ public void actionPerformed(ActionEvent e){String str = result.getText();double i = DatatypeConverter.parseDouble(str);i = i*i;result.setText("" + i);}};ActionListener multiply1 = new ActionListener(){ public void actionPerformed(ActionEvent e){ String str = result.getText();a = DatatypeConverter.parseDouble(str);flag = "*";result.setText("");}};ActionListener divide1 = new ActionListener(){ public void actionPerformed(ActionEvent e){ String str = result.getText();a = DatatypeConverter.parseDouble(str);flag = "/";result.setText("");}};ActionListener add1 = new ActionListener(){ public void actionPerformed(ActionEvent e){ String str = result.getText();a = DatatypeConverter.parseDouble(str);flag = "+";result.setText("");}};ActionListener reduce1 = new ActionListener(){ public void actionPerformed(ActionEvent e){ String str = result.getText();a = DatatypeConverter.parseDouble(str);flag = "-";result.setText("");}};ActionListener reset1 = new ActionListener(){ public void actionPerformed(ActionEvent e){ result.setText("0");}};ActionListener point1 = new ActionListener(){public void actionPerformed(ActionEvent e){String str = result.getText();result.setText(str + ".");}};ActionListener equal1 = new ActionListener(){ //实现四则运算public void actionPerformed(ActionEvent e){String str = result.getText();b = DatatypeConverter.parseDouble(str);{if(flag == "+")c = a + b;else if(flag == "-")c = a - b;else if(flag == "*")c = a * b;else if(flag == "/" || b != 0)c = a / b;}if(flag != "=")result.setText("" + c);elseresult.setText("零不能做除数！");a = 0;b = 0;c = 0;flag = "";}};}。