结对练习——Caculator
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CalString.java
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核心代码:// 计算整个表达式值的函数
static double calculate(String s) {
s += "#";
int i = 0;// 表达式循环条件
char c;// 表达式中的一个字符
Stacknum = new Stack ();// 操作数栈
Stackop = new Stack ();// 操作符栈
op.push('#');// 表达式开始的标志
c = s.substring(i, i + 1).charAt(0);// 取出表达式中的一位
while (c != '#' || op.peek().toString().charAt(0) != '#'){// 没有取到表达式开始或结束的标志'#',就循环计算表达式的值
if (!issign(c)){
int start = i;
int end = 0;
while (!issign(s.substring(i, i + 1).charAt(0)))
end = i++;
double m = Double.parseDouble(s.substring(start, end + 1));
num.push(m);
c = s.substring(i, i + 1).charAt(0);
}
else{
switch (co(op.peek(), c)){
case -1:
op.push(c);
i++;
c = s.substring(i, i + 1).charAt(0);
break;
case 0:
op.pop();
i++;
c = s.substring(i, i + 1).charAt(0);
break;
case 1:
double a = num.pop();
double b = num.pop();
char ss = op.pop();
num.push(cal(a, ss, b));
break;
}
}
}
return num.peek();
}
利用栈先进后出的特点,计算混合四则运算表达式。 -
FindBugs:
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单元测试:
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代码覆盖率:
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Caculator.java
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运行:
测试:1+1=2
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扩展
扩展后的Caculator.java
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核心代码:
package com.calculator;import java.awt.;
import java.awt.event.;import javax.swing.*;
import java.util.Vector;
import java.math.BigDecimal;public class Calculator {
// temp记录每次的输入m
String temp = "";@SuppressWarnings("rawtypes")
// Vector vt = new Vector(20, 10);
// 记录每次表达式的计算结果(未完成)m
Vector vtemp = new Vector(20, 10);// 声明各个UI组件对象并初始化
JFrame frame = new JFrame("Calculator");
JTextField result_TextField = new JTextField(temp, 20);
JButton clear_Button = new JButton("Clear");
JButton button0 = new JButton("0");
JButton button1 = new JButton("1");
JButton button2 = new JButton("2");
JButton button3 = new JButton("3");
JButton button4 = new JButton("4");
JButton button5 = new JButton("5");
JButton button6 = new JButton("6");
JButton button7 = new JButton("7");
JButton button8 = new JButton("8");
JButton button9 = new JButton("9");
JButton button_Dian = new JButton(".");
JButton button_jia = new JButton("+");
JButton button_jian = new JButton("-");
JButton button_cheng = new JButton("*");
JButton button_chu = new JButton("/");
JButton button_dy = new JButton("=");
JButton button_zuo = new JButton("(");
JButton button_you = new JButton(")");
JButton button_kong = new JButton("待定");
JButton button_kong2 = new JButton("待定");// 计算机类的构造器
public Calculator() {// 为按钮设置等效键,即可以通过对应的键盘按键来代替点击它
button0.setMnemonic(KeyEvent.VK_0);
// 其它等效键省略,你可以自行补充完整// 设置文本框为右对齐,使输入和结果都靠右显示
result_TextField.setHorizontalAlignment(JTextField.RIGHT);// 将UI组件添加进容器内
JPanel pan = new JPanel();
pan.setLayout(new GridLayout(5, 5, 5, 5));
pan.add(button_zuo);
pan.add(button_you);
pan.add(button_kong);
pan.add(button_kong2);
pan.add(button7);
pan.add(button8);
pan.add(button9);
pan.add(button_chu);
pan.add(button4);
pan.add(button5);
pan.add(button6);
pan.add(button_cheng);
pan.add(button1);
pan.add(button2);
pan.add(button3);
pan.add(button_jian);
pan.add(button0);
pan.add(button_Dian);
pan.add(button_dy);
pan.add(button_jia);
pan.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));JPanel pan2 = new JPanel();
pan2.setLayout(new BorderLayout());
pan2.add(result_TextField, BorderLayout.WEST);
pan2.add(clear_Button, BorderLayout.EAST);// 设置主窗口出现在屏幕上的位置
frame.setLocation(300, 200);
// 设置窗体不能调大小
frame.setResizable(false);
frame.getContentPane().setLayout(new BorderLayout());
frame.getContentPane().add(pan2, BorderLayout.NORTH);
frame.getContentPane().add(pan, BorderLayout.CENTER);frame.pack();
frame.setVisible(true);// 事件处理程序
// 数字键
class Listener implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
temp += ((JButton) e.getSource()).getText();
result_TextField.setText(temp);
vtemp.add(temp);
}
}// 输入的运算符号的处理
class Listener_signal implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
temp += ((JButton) e.getSource()).getText();
result_TextField.setText(temp);
vtemp.add(temp);
}
}// 清除键的逻辑(Clear)
class Listener_clear implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
temp = "";
result_TextField.setText(temp);
vtemp.clear();
}
}// 等于键的逻辑
class Listener_dy implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
CalString cs = new CalString();
String k = temp;
temp += ((JButton) e.getSource()).getText();
vtemp.add(((JButton) e.getSource()).getText());
//result_TextField.setText(temp);
temp += cs.calculate(k);
result_TextField.setText(temp);
vtemp.add(cs.calculate(k));
temp = "";
// 测试
for (int i=0;i<vtemp.size();i++) {
System.out.println(vtemp.get(i));
}
}
}// 小数点的处理
class Listener_xiaos implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
temp += ((JButton) e.getSource()).getText();
result_TextField.setText(temp);
vtemp.add(temp);
}
}// 监听括号
class Listener_kuoh implements ActionListener {
@SuppressWarnings("unchecked")
public void actionPerformed(ActionEvent e) {
temp += ((JButton) e.getSource()).getText();
result_TextField.setText(temp);
vtemp.add(temp);
}
}// 注册各个监听器,即绑定事件响应逻辑到各个UI组件上
Listener_dy jt_dy = new Listener_dy();// 监听数字键
Listener jt = new Listener();
// 监听符号键
Listener_signal jt_signal = new Listener_signal();
// 监听清除键
Listener_clear jt_c = new Listener_clear();
// 监听小数点键
Listener_xiaos jt_xs = new Listener_xiaos();
// 监听括号键
Listener_kuoh jt_kh = new Listener_kuoh();button_zuo.addActionListener(jt_kh);
button_you.addActionListener(jt_kh);
button7.addActionListener(jt);
button8.addActionListener(jt);
button9.addActionListener(jt);
button_chu.addActionListener(jt_signal);
button4.addActionListener(jt);
button5.addActionListener(jt);
button6.addActionListener(jt);
button_cheng.addActionListener(jt_signal);
button1.addActionListener(jt);
button2.addActionListener(jt);
button3.addActionListener(jt);
button_jian.addActionListener(jt_signal);
button0.addActionListener(jt);
button_Dian.addActionListener(jt_xs);
button_dy.addActionListener(jt_dy);
button_jia.addActionListener(jt_signal);
clear_Button.addActionListener(jt_c);// 窗体关闭事件的响应程序
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});}
@SuppressWarnings("unused")
public static void main(String[] args) {
// 设置程序显示的界面风格,可以去除
try {
UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
} catch (Exception e) {
e.printStackTrace();
}Calculator cal = new Calculator();
}
}
所有的计算逻辑都通过CalString.java的方法来完成,原Caculator.java的所有与计算逻辑有关的方法都删去,仅起到图形化的作用。
四则混合运算与图形界面:
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运行结果:
测试:(1+1)×5=10
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PSP:

此次项目的码云地址:https://gitee.com/L_Name/myCaculator/tree/master
小结
设计实现混合四则运算时想岔了导致花费了大量的时间,在请教他人、多次修改代码之得以正常运行。数字键、符号键、小数点键、括号键实质上都是获取字符然后传入String temp变量再在result_TextField.setText(String s)上设置,所以可以在一个监听中完成,为图方便就没有更改。














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