使用java写的一个简易的计算器,可以检测输入是否合法.doc

/* 使用java编写的简易计算器，可以实现+，-,*,/四则运算。注意： 括号没有作用，就是一个装饰。待日后有时间定会更新。DEL是退格，CLC是清空。并带有日期，输入语法检测功能 */import java.awt.BorderLayout;import java.awt.Button;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.JOptionPane;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.JTextField;import javax.swing.ScrollPaneConstants;import javax.swing.Timer;public class Calculator extends JFrame implements ActionListenerprivate String operandString = ;public static Calculator cal;private JTextArea textArea;private JPanel panel;private Container container;private double operand = new double100; private int operandCount;private String operator = new String100; private int operatorCount;private JScrollPane jScrollPane;public Calculator(String title)super(title);public Calculator()operand = new double200;operator = new String100;cal = new Calculator(计算器);cal.setTitle(Calculator);container = cal.getContentPane();container.setBackground(null);cal.setBackground(new Color(100, 250, 150);cal.setSize(320, 400);cal.setLocation(100, 100);container.setLayout(new GridLayout(0, 1, 2, 1);new DateApplication().getNewInstance();showComponent();cal.setDefaultCloseOperation(EXIT_ON_CLOSE);cal.setResizable(false);cal.setVisible(true);private void showComponent()/ container.add(new JTextArea(40,20),BorderLayout.NORTH);String textString = 789+456-123*0./=;textArea = new JTextArea(1, 2);jScrollPane = new JScrollPane(textArea);System.out.println(jScrollPane= + jScrollPane);textArea.setBackground(Color.CYAN);textArea.setForeground(Color.BLACK);textArea.setEditable(false);textArea.setFont(new Font(, Font.BOLD, 30);textArea.setWrapStyleWord(true);textArea.setLineWrap(true);jScrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);/ jScrollPane.setViewportView(textArea);container.add(jScrollPane);panel = new JPanel();panel.setLayout(new GridLayout(5, 4);for (int i = 0; i 0)operandString = operandString.substring(0,operandString.length() - 1);textArea.setText(operandString);return;if (str.equals(CLC)operandString = ;textArea.setText(operandString);return;operandString = operandString + str;System.out.println(operandString);operandString.trim();textArea.setText(operandString);if (str.equals(=)handleString(operandString);public void handleString(String alString)int beginIndex = 0;String temp = null;for (int i = 0; i alString.length(); i+)if (containsOperator(alString.substring(i, i + 1)operatoroperatorCount = alString.substring(i, i + 1);operatorCount+;if (operatorCount = 1)temp = alString.substring(0, i);beginIndex = i;elsetemp = alString.substring(beginIndex + 1, i);beginIndex = i;checkLegal(temp);/ for (int i = 0; i operatorCount; i+)/ System.out.println(operatori);countResult();public boolean containsOperator(String substring)/ TODO Auto-generated method stubString str = +-*/=;if (str.contains(substring)return true;return false;public void checkLegal(String str)double tempDouble = 0;trytempDouble = Double.parseDouble(str);operandoperandCount = tempDouble;operandCount+;catch (Exception e)JOptionPane.showMessageDialog(null, 输入有错);operandString = operandString + =;textArea.setText(operandString);public void countResult()double tempResult;for (int i = 0; i operatorCount - 1; i+)if (operatori.equals(*)tempResult = operandi * operandi + 1;backFunc(tempResult, i);i-;else if (operatori.equals(/)trytempResult = operandi / operandi + 1;catch (Exception e)JOptionPane.showMessageDialog(null, 除数不能为0);operandString = operandString + =;return;backFunc(tempResult, i);i-;tempResult = operand0;for (int i = 0; i operandCount; i+)if (operatori.equals(+)tempResult += operandi + 1;if (operatori.equals(-)tempResult -= operandi + 1;if (operatori.equals(=)break;int similarInteger = Calculator.round(tempResult);textArea.setForeground(Color.RED);if (Math.abs(tempResult - similarInteger) Math.pow(10, -7)operandString += similarInteger;System.out.println(similarInteger);textArea.append(String.valueOf(similarInteger);elseoperandString += tempResult;textArea.append(String.valueOf(tempResult);public void backFunc(double digital, int i)int loo