使用java写的一个简易的计算器,可以检测输入是否合法.doc

1、/* 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.Actio

2、nListener；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 ex

3、tends 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

4、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.setBa

5、ckground（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

6、showComponent（）/ container。add(new JTextArea（40，20）,BorderLayout.NORTH);String textString = ”789+456-1230。/="；textArea = new JTextArea(1, 2);jScrollPane = new JScrollPane(textArea）;System.out.println("jScrollPane=" + jScrollPane)；textArea.setBackground(Color。CYAN)；textArea.setForegrou

7、nd(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（jScrollPa

8、ne)；panel = new JPanel();panel。setLayout（new GridLayout（5, 4）);for （int i = 0; i textString.length（); i+）addButton(textString。substring（i， i + 1)， panel)；String leftBracket = ”（”；String rightBracket = ”）"；String back = "DEL"String setNull = "CLC"/ panel.add(new JButton（leftB

9、racket)）;/ panel。add（new JButton（rigthBracke）;/ panel.add(new JButton（back);/ panel.add（new JButton(setNull）)；addButton（leftBracket, panel)；addButton（rightBracket， panel）;addButton(back, panel)；addButton（setNull， panel)；container。add(panel)；private void addButton（String str， JPanel panel2）/ TODO Aut

10、ogenerated method stubButton button = new Button（str）；button.setFont（new Font(""， Font。BOLD, 14）);if （button.getLabel（）。equals（"。”)| button.getLabel(）。equals（”）button.setFont（new Font（""， Font.BOLD， 30）)；if (button.getLabel(）.equals(”-")button.setFont(new Font(”， Font.B

11、OLD， 24）)；button。setBackground（Color.GREEN)；button。addActionListener（this）；panel2。add(button）;public static void main（String args)new Calculator()；Overridepublic void actionPerformed(ActionEvent e)textArea.setForeground(Color。BLACK）;String str = e。getActionCommand（);/ System.out.println（str)；/ if（op

12、erandString=nulloperandString.contains(s）if (operandString.contains（”=”)operandString = "”；textArea.setText(operandString);operand = new double200；operator = new String200;operandCount = 0;operatorCount = 0;if (str。equals(”(”） | str。equals(”）"）return；if (str。equals（"DEL”)if (operandSt

13、ring.length() > 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）;operandStr

14、ing.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.subs

15、tring(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（Str

16、ing substring)/ TODO Autogenerated 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。sho

17、wMessageDialog(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 （op

18、eratori。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) < M