java代码---------计算器实现

package com.rue;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

//实现计算器的功能，我他妈的真是不懂变通。

class Ji extends JFrame implements ActionListener {
private static final String CE = null;
// 定义按钮
StringBuffer str = new StringBuffer();
JButton jb_0, jb_1, jb_2, jb_3, jb_4, jb_5, jb_6, jb_7, jb_8, jb_9, jb_jia,
jb_jian, jb_cheng, jb_chu, jb_dian, jb_deng, jb_delete;
JLabel jf;
double num1 = 0;
double num2 = 0;
char c = '\0';
double m;
boolean ready = true;

public Ji() {
JPanel jp = new JPanel(new GridLayout(5, 4));// 把所有的按钮组件和文本框放在这个panel里面
jf = new JLabel("0.0");
jf.setFont(new Font("", 1, 18));
jf.setHorizontalAlignment(JLabel.RIGHT);
jb_delete = new JButton("CE");// 设一个删除的按钮
jb_0 = new JButton("0");
JButton jb_genghao = new JButton("√");
jb_1 = new JButton("1");
jb_genghao.addActionListener(this);
jb_2 = new JButton("2");
jb_3 = new JButton("3");
jb_4 = new JButton("4");
jb_5 = new JButton("5");
jb_6 = new JButton("6");
jb_7 = new JButton("7");
jb_8 = new JButton("8");
jb_9 = new JButton("9");
jb_jia = new JButton("+");
jb_jian = new JButton("-");
jb_cheng = new JButton("*");
jb_chu = new JButton("/");
jb_dian = new JButton(".");
jb_deng = new JButton("=");
//
jb_delete.addActionListener(this);
jb_0.addActionListener(this);
jb_1.addActionListener(this);
jb_2.addActionListener(this);
jb_3.addActionListener(this);
jb_4.addActionListener(this);
jb_5.addActionListener(this);
jb_6.addActionListener(this);
jb_7.addActionListener(this);
jb_8.addActionListener(this);
jb_9.addActionListener(this);
jb_jia.addActionListener(this);
jb_jian.addActionListener(this);
jb_cheng.addActionListener(this);
jb_chu.addActionListener(this);
jb_dian.addActionListener(this);
jb_deng.addActionListener(this);

JButton jb_Back = new JButton("Back");
jb_Back.addActionListener(this);

jp.add(jb_1);
jp.add(jb_2);
jp.add(jb_3);
jp.add(jb_4);
jp.add(jb_5);
jp.add(jb_6);
jp.add(jb_7);
jp.add(jb_8);
// this.add(jp);

jp.add(jb_9);

jp.add(jb_jia);
jp.add(jb_jian);
jp.add(jb_cheng);
jp.add(jb_chu);
jp.add(jb_dian);
jp.add(jb_deng);
jp.add(jb_0);
jp.add(jb_Back);
jp.add(jb_delete);
jp.add(jb_genghao);
this.add(jf, BorderLayout.NORTH);
this.add(jp);

// this.setLayout();
this.setVisible(true);

this.setBounds(100, 20, 230, 300);
this.setDefaultCloseOperation(3);

}

public double count() {
switch (c) {
case '+':
m = num1 + num2;
break;
case '-':
m = num1 - num2;
break;
case '*':
m = num1 * num2;
break;
case '/':
m = num1 / num2;
break;
case '√':
m = Math.sqrt(num1);
break;
case 'E':
m = '\0';
}

return m;
}

public void actionPerformed(ActionEvent e) {
String str = e.getActionCommand();
if (str.equals("0") || str.equals(".") || str.equals("1")
|| str.equals("2") || str.equals("3") || str.equals("4")
|| str.equals("5") || str.equals("6") || str.equals("7")
|| str.equals("8") || str.equals("9") || str.equals("1")) {
if (ready) {
jf.setText(str);
ready = false;
} else {

jf.setText(jf.getText() + str);
ready = false;
}

} else if (str.equals("+")) {
num1 = Double.parseDouble(jf.getText());
// count();
// ////////////其实可以感觉到操作符有点不正常的。就是操作符设置的问题有点大
// if(num1=){}
c = '+';

ready = true;
} else if (str.equals("√")) {
num1 = Double.parseDouble(jf.getText());
c = '√';
ready = true;
} else if (str.equals("CE")) {
num1 = Double.parseDouble(jf.getText());
// c='c';//这里可以判断按的是哪一个按钮吗？
jf.setText("0.0");// 记住这里是要清空，但并不是把lable也全部删除看不见。Label的作用。
ready = true;// 当这里为false时，它会与0.0连接一起显示出来，此时设置我ture。它正常了。是不是继续执行下一步的意思呢？

} else if (str.equals("-")) {
num1 = Double.parseDouble(jf.getText());
c = '-';
ready = true;
} else if (str.equals("*")) {
num1 = Double.parseDouble(jf.getText());
c = '*';
ready = true;
} else if (str.equals("/")) {
num1 = Double.parseDouble(jf.getText());
c = '/';
ready = true;
} else if (str.equals("=")) {
num2 = Double.parseDouble(jf.getText());

jf.setText(count() + "");

ready = false;
}

}

}

public class Test {
public static void main(String[] args) {
new Ji();
}
}