public abstract class Operation {protected double numberA = 0;protected double numberB = 0;protected double result = 0;public double getNumberA() {return numberA;}public void setNumberA(double numberA) {this.numberA = numberA;}public double getNumberB() {return numberB;}public void setNumberB(double numberB) {this.numberB = numberB;}public abstract double getResult();
}class OperationAdd extends Operation{@Overridepublic double getResult() {double result = 0;result = numberA + numberB;return result;}
}
class OperationSub extends Operation{@Overridepublic double getResult() {result = numberA - numberB;return result;}
}
class OperationMul extends Operation{@Overridepublic double getResult() {result = numberA * numberB;return result;}
}
class OperationDiv extends Operation{@Overridepublic double getResult(){try {result = numberA / numberB;} catch (Exception e) {System.out.println("除数不能为0");e.printStackTrace();}return result;}
}

//简单工厂模式
//只需要传入运算符号，工厂就实例化出合适的对象，用过多态，返回父类的方式实现计算器的结果
public class OperationFactory {public static Operation createOperate(char sign) {Operation operation = null;switch (sign) {case '+':operation = new OperationAdd();break;case '-':operation = new OperationSub();break;case '*':operation = new OperationMul();break;case '/':operation = new OperationDiv();break;default:break;}return operation;}
}

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextField;@SuppressWarnings("serial")
public class CalculateFrame extends JFrame{private JTextField textData1, textData2, textResult;private JLabel labelNum1, labelNum2, labelResult;private JRadioButton radioAdd, radioSub, radioMul, radioDiv;private JButton btnCalculate;private Operation oper;//进行运算的两个数字和结果private String data1, data2, operation;private double resultNum;public CalculateFrame(){        //设置窗口基本属性this.setTitle("简单计算器");this.setSize(300, 200);//本机分辨率为1366*768this.setLocation(1366/2-300/2, 768/2-200/2);//this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        this.addWindowListener(new WindowAdapter(){@Overridepublic void windowClosing(WindowEvent e) {setVisible (false);System.exit(0);}});initView();initLayout();this.setVisible(true);//显示窗口btnCalculate.addActionListener(new ButtonListener());    }//设置一些功能区域public void initView() {textData1 = new JTextField();textData2 = new JTextField();textResult = new JTextField();textResult.setEnabled(false);labelNum1 = new JLabel("第一个数：");labelNum2 = new JLabel("第二个数：");labelResult = new JLabel("结果：");btnCalculate = new JButton("计算");radioAdd = new JRadioButton("+");radioSub = new JRadioButton("-");radioMul = new JRadioButton("*");radioDiv = new JRadioButton("/");}//将控件加入到布局中public void initLayout() {JPanel p1 = new JPanel(new GridLayout(1,2));p1.add(labelNum1);p1.add(textData1);JPanel p2 = new JPanel(new GridLayout(1,4));p2.add(radioAdd);p2.add(radioSub);p2.add(radioMul);p2.add(radioDiv);    JPanel p3 = new JPanel(new GridLayout(1,2));p3.add(labelNum2);p3.add(textData2);JPanel p4 = new JPanel(new GridLayout(1,2));p4.add(labelResult);p4.add(textResult);JPanel p5 = new JPanel(new GridLayout(1,1));p5.add(btnCalculate);    this.setLayout(new GridLayout(5,1));        this.add(p1);this.add(p2);this.add(p3);this.add(p4);this.add(p5);        ButtonGroup group = new ButtonGroup();group.add(radioAdd);group.add(radioSub);group.add(radioMul);group.add(radioDiv);}class ButtonListener implements ActionListener{//从程序中读入数据public void actionPerformed(ActionEvent e) {data1 = textData1.getText();data2 = textData2.getText();operation = "";if(radioAdd.isSelected())        operation = radioAdd.getText();else if(radioSub.isSelected())    operation = radioSub.getText();                else if(radioMul.isSelected())    operation = radioMul.getText();                else if(radioDiv.isSelected())    operation = radioDiv.getText();//将运算符号传入工厂中进行实例化oper = OperationFactory.createOperate(operation.charAt(0));oper.numberA = Double.parseDouble(data1);oper.numberB = Double.parseDouble(data2);resultNum = oper.getResult();textResult.setText(String.valueOf(resultNum));}}
}

public class Main {public static void main(String[] args) {new CalculateFrame();}
}