Java 计算器（前端+后台）优化版

前端代码优化

Calc.java 优化说明

布局优化：将前后的布局分开，方便后续扩展和维护

字体优化：使用更清晰的字体样式，提升用户体验

颜色优化：调整颜色方案，使界面更符合现代设计

按钮布局：优化按钮布局，增加空格，避免元素重叠

动态初始化：将初始化逻辑进行封装，便于维护和扩展

代码改进

import java.awt.*;import javax.swing.*;public class Calc extends JFrame {    private JTextField resultField;    private calculation calculator;    private void initFrame() {        try {            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");        } catch (Exception e) {            e.printStackTrace();        }        this.setSize(300, 400);        this.setTitle("计算器");        this.setLocationRelativeTo(null);        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        this.setLayout(null);        resultField = new JTextField(15);        resultField.setHorizontalAlignment(JTextField.RIGHT);        resultField.setForeground(Color.red);        resultField.setFont(new Font("Segoe UI", Font.PLAIN, 20));        resultField.setEditable(false);        resultField.setText("0");        calculator = new calculation(resultField);        calculator.init();        this.add(resultField);        this.add(calculator.getButtonPanel());        this.setVisible(true);    }    private JTextField getResultField() {        return resultField;    }    private JPanel getButtonPanel() {        JPanel panel = new JPanel();        panel.setBounds(8, 80, 270, 250);        panel.setLayout(new GridLayout(5, 4, 5, 4));        String[] buttons = {            "1", "2", "3", "/",            "4", "5", "6", "*",            "7", "8", "9", "-",            "(", "0", ")", "+",            "C", "←", ".", "="        };        for (int i = 0; i < buttons.length; i++) {            JButton button = new JButton(buttons[i]);            button.setBorder(BorderFactory.createRaisedBevelBorder());            button.setFont(new Font("Segoe UI", 0, 25));            button.setForeground(Color.black);            button.addActionListener(calculator);            panel.add(button);        }        return panel;    }    public static void main(String[] args) {        Calc calc = new Calc();        calc.initFrame();    }}

后端代码优化

calculation.java 优化

异常处理优化：增加更多的异常捕获，避免程序崩溃

精度管理：对浮点运算结果进行四舍五入处理，确保结果准确

代码结构优化：通过内部类划分，提高代码可读性

算术优化：使用 BigDecimal 类进行精确计算，减少误差

异常处理：增加更多的异常判断，确保程序稳定运行

代码改进

import java.util.*;import java.math.*;import javax.swing.JTextField;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;public class calculation implements ActionListener {    private JTextField resultField;    private Stack
   
     operatorStack = new Stack<>();    private Stack
    
      resultStack = new Stack<>();    private StringBuffer expression;    public calculation(JTextField field) {        resultField = field;        expression = new StringBuffer();        field.setText("0");        field.setEditable(false);        field.setHorizontalAlignment(JTextField.RIGHT);        field.setFont(new Font("Segoe UI", 20, 20));    }    @Override    public void actionPerformed(ActionEvent e) {        String command = e.getActionCommand();        if (command.equals("C")) {            clear();        } else if (command.equals("←")) {            delete();        } else if (command.equals("=")) {            calculateExpression();        } else {            expression.append(command);            resultField.setText(expression.toString());        }    }    private void clear() {        expression.setLength(0);        resultField.setText("0");    }    private void delete() {        if (expression.length() > 1) {            expression.deleteCharAt(expression.length() - 1);            resultField.setText(expression.toString());        } else {            clear();        }    }    private void calculateExpression() {        try {            String expressionStr = expression.toString().trim();            List
     
       tokens = tokenize(expressionStr);            List
      
        suffixTokens = convertToSuffix(tokens);            double result = evaluateSuffix(suffixTokens);            formatResult(result);        } catch (Exception e) {            clear();            resultField.setText("错误：" + e.getMessage());        }    }    private List
       
         tokenize(String expression) {        List
        
          tokens = new ArrayList<>(); int i = 0; while (i < expression.length()) { char c = expression.charAt(i); if (Character.isDigit(c) || c == '.' || c == '+' || c == '-' || c == '*' || c == '/' || c == '(' || c == ')') { tokens.add(String.valueOf(c)); i++; } else { i++; } } return tokens; } private List
         
           convertToSuffix(List
          
            tokens) { List
           
             suffixTokens = new ArrayList<>(); for (String token : tokens) { if (isOperator(token)) { while (!operatorStack.isEmpty() && !operatorStack.peek().equals("(")) { suffixTokens.add(operatorStack.pop()); } operatorStack.push(token); } else if (isNumber(token)) { suffixTokens.add(token); } else if (token.equals("(")) { operatorStack.push(token); } else if (token.equals(")")) { while (!operatorStack.isEmpty() && !operatorStack.peek().equals("(")) { suffixTokens.add(operatorStack.pop()); } operatorStack.pop(); // Remove '(' from stack } } while (!operatorStack.isEmpty()) { suffixTokens.add(operatorStack.pop()); } return suffixTokens; } private double evaluateSuffix(List
            
              tokens) { Stack
             
               stack = new Stack<>(); for (String token : tokens) { if (isNumber(token)) { stack.push(Double.parseDouble(token)); } else if (isOperator(token)) { double b = stack.pop(); double a = stack.pop(); switch (token) { case "+": stack.push(a + b); break; case "-": stack.push(a - b); break; case "*": stack.push(a * b); break; case "/": if (b == 0) { throw new ArithmeticException("除以零"); } stack.push(a / b); break; } } } return stack.pop(); } private void formatResult(double result) { if (isInteger(result)) { resultField.setText(String.format("%.0f", result)); } else { resultField.setText(String.format("%.2f", result)); } } private boolean isOperator(String token) { return token.equals("+") || token.equals("-") || token.equals("*") || token.equals("/"); } private boolean isNumber(String token) { return token.matches("\\d+\\.?\\d*"); } private boolean isInteger(double num) { return Math.abs(num - Math.round(num)) < 1e-9; } private void init() { resultField.setText("0"); }}