java-计算器模板及源码

大家好，又见面了，我是你们的朋友全栈君。

计算器实现了大部分基础功能：基本运算，菜单栏选项，并且拓展了普通型和科学兴选项等等，读者可以在此基础上进行修改和拓展。其他具体实现方法可以看源码，里面有详细的概述，代码框架清晰。

读者在阅读和引用过程中，如有问题欢迎评论区留言和私信交流。

运行环境：win10 Eclipse IDE for Java Developers – 2020-06

下面是计算器的视图：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

/* * 计算器 */
public class CaculatorTest implements ActionListener { 
   
	// 初始框架搭建
	JFrame frame = new JFrame("计算器");
	JTextField area = new JTextField("0");
	JPanel panel1 = new JPanel();
	JPanel panel2 = new JPanel();
	JButton[] buttons = new JButton[20];
	String[] buttonsText = { 
    "sqrt", "退格", "C", "/", "7", "8", "9", "*", "4", "5", "6", "-", "1", "2", "3", "+", "0",
			".", "+/-", "=" };
	boolean point = false; // 用于判断是否输入多位小数点
	boolean key = true; // 做完运算("=")后继续输入数字
	String sign = " "; // 用于判断和记录运算符号
	double temp = 0; // 多次连续运算时，值的寄存处

	public CaculatorTest() { 
   
		initMenu();
		initText();
		initExtend();
		initFrame();
		initBorderLayout();
	}

	// 初始化菜单
	private void initMenu() { 
   
		JMenuBar mb = new JMenuBar();
		JMenu m1 = new JMenu("选项");
		JMenu m2 = new JMenu("编辑");
		JMenu m3 = new JMenu("帮助");
		JMenuItem m11 = new JMenuItem("普通型计算器");
		JMenuItem m12 = new JMenuItem("科学型计算器");
		m1.add(m11);
		m1.add(m12);
		m11.addActionListener(new ActionListener() { 
   
			@Override
			public void actionPerformed(ActionEvent e) { 
   
				boolean flag = false;
				panel2.setVisible(flag);
				frame.pack();
			}
		});
		m12.addActionListener(new ActionListener() { 
   
			@Override
			public void actionPerformed(ActionEvent e) { 
   
				boolean flag = true;
				panel2.setVisible(flag);
				frame.pack();
			}
		});
		mb.add(m1);
		mb.add(m2);
		mb.add(m3);
		frame.setJMenuBar(mb);
	}

	// 初始化输出文本域
	private void initText() { 
   
		area.setFont(new Font("TimesRoman", Font.PLAIN, 20));
		area.setSize(400, 100);
		area.setHorizontalAlignment(JTextField.RIGHT); // 向右显示
	}

	// 初始化拓展功能
	private void initExtend() { 
   
		panel2.setLayout(new GridLayout(1,4,1,1));
		JButton b1 = new JButton("sin");
		JButton b2 = new JButton("cos");
		JButton b3 = new JButton("exp");
		JButton b4 = new JButton("ln");
		b1.setFont(new Font("TimesRoman", Font.PLAIN, 20));
		b2.setFont(new Font("TimesRoman", Font.PLAIN, 20));
		b3.setFont(new Font("TimesRoman", Font.PLAIN, 20));
		b4.setFont(new Font("TimesRoman", Font.PLAIN, 20));
		b1.setSize(100, 100);
		b1.addActionListener(this);
		b2.setSize(100, 100);
		b2.addActionListener(this);
		b3.setSize(100, 100);
		b3.addActionListener(this);
		b4.setSize(100, 100);
		b4.addActionListener(this);
		panel2.add(b1);
		panel2.add(b2);
		panel2.add(b3);
		panel2.add(b4);
	}

	// 初始化计算器基本界面
	private void initFrame() { 
   
		panel1.setLayout(new GridLayout(5, 4, 1, 1));
		for (int i = 0; i < buttonsText.length; i++) { 
   
			JButton button = new JButton(buttonsText[i]);
			button.setSize(100, 100);
			button.setFont(new Font("TimesRoman", Font.PLAIN, 20));
			button.addActionListener(this);
			panel1.add(button);
		}
	}

	// 初始化计算器总基本界面
	private void initBorderLayout() { 
   
		frame.setLayout(new BorderLayout());
		frame.add(panel1, BorderLayout.SOUTH); // 插入组件
		frame.add(area, BorderLayout.NORTH);
		frame.add(panel2, BorderLayout.CENTER);
		frame.setLocation(700, 400);
		frame.setSize(400, 700);
		frame.setVisible(true); // 设置可见
		panel2.setVisible(false);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 可以关闭
		frame.pack();
	}

	public static void main(String[] args) { 
   
		new CaculatorTest();
	}

	@Override
	// 事件监听
	public void actionPerformed(ActionEvent e) { 
   
		String str = e.getActionCommand();
		String str2 = area.getText();
		if (str == "0" || str == "1" || str == "2" || str == "3" || str == "4" || str == "5" || str == "6" || str == "7"
				|| str == "8" || str == "9") { 
   
			if (key == false) { 
   
				area.setText(str2 + str);
			} else { 
   
				area.setText(str);
				key = false;
			}
		} else if (str == "C") { 
   
			area.setText("0");
			sign = " ";
			key = true;
		} else if (str == ".") { 
   
			if (point == false) { 
   
				area.setText(str2 + str);
				point = true;
			} else { 
   
				area.setText("double poits!press C to update!");
				point = false;
			}
		} else if (str == "+/-") { 
   
			double num = Double.valueOf(str2);
			num = -num;
			area.setText(String.valueOf(num));
		} else if (str == "退格") { 
   
			if (str2.length() == 0) { 
   
				area.setText("can't be deleted!please press C!");
			} else { 
   
				str2 = str2.substring(0, str2.length() - 1);
				area.setText(str2);
			}
		} else if (str == "sqrt") { 
   
			area.setText("");
			sign = "s";
		} else if (str == "sin") { 
   
			area.setText("");
			sign = "sin";
		} else if (str == "cos") { 
   
			area.setText("");
			sign = "cos";
		} else if (str == "exp") { 
   
			area.setText("");
			sign = "exp";
		} else if (str == "ln") { 
   
			area.setText("");
			sign = "ln";
		} else { 
   
			if (str == "+") { 
   
				if (sign == " ") { 
   
					sign = "+";
					temp = Double.valueOf(str2);
					area.setText("");
				} else if (sign == "-") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = temp - Double.valueOf(str2);
						sign = "+";
						area.setText("");
						key = true;
					}
				} else if (sign == "+") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = temp + Double.valueOf(str2);
						sign = "+";
						area.setText("");
						key = true;
					}
				} else if (sign == "*") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = temp * Double.valueOf(str2);
						sign = "+";
						area.setText("");
						key = true;
					}
				} else if (sign == "/") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else if (Double.valueOf(str2) == 0) { 
   
						area.setText("除数不能为0哦！按 C");
					} else { 
   
						temp = temp / Double.valueOf(str2);
						area.setText("");
						sign = "+";
						key = true;
					}
				} else if (sign == "s") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = Math.sqrt(Double.valueOf(str2));
						area.setText("");
						sign = "+";
					}
				} else if (sign == "sin") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = Math.sin(Double.valueOf(str2));
						area.setText("");
						sign = "+";
					}
				} else if (sign == "cos") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = Math.cos(Double.valueOf(str2));
						area.setText("");
						sign = "+";
					}
				} else if (sign == "exp") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = Math.exp(Double.valueOf(str2));
						area.setText("");
						sign = "+";
					}
				} else if (sign == "ln") { 
   
					if (str2.length() == 0) { 
   
						sign = "+";
					} else { 
   
						temp = Math.log(Double.valueOf(str2));
						area.setText("");
						sign = "+";
					}
				}
			} else if (str == "-") { 
   
				if (sign == " ") { 
   
					sign = "-";
					temp = Double.valueOf(str2);
					area.setText("");
				} else if (sign == "-") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = temp - Double.valueOf(str2);
						sign = "-";
						area.setText("");
						key = true;
					}
				} else if (sign == "+") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = temp + Double.valueOf(str2);
						sign = "-";
						area.setText("");
						key = true;
					}
				} else if (sign == "*") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = temp * Double.valueOf(str2);
						sign = "-";
						area.setText("");
						key = true;
					}
				} else if (sign == "/") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else if (Double.valueOf(str2) == 0) { 
   
						area.setText("除数不能为0哦！按 C");
					} else { 
   
						temp = temp / Double.valueOf(str2);
						area.setText("");
						sign = "-";
						key = true;
					}
				} else if (sign == "s") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = Math.sqrt(Double.valueOf(str2));
						area.setText("");
						sign = "-";
					}
				} else if (sign == "sin") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = Math.sin(Double.valueOf(str2));
						area.setText("");
						sign = "-";
					}
				} else if (sign == "cos") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = Math.cos(Double.valueOf(str2));
						area.setText("");
						sign = "-";
					}
				} else if (sign == "exp") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = Math.exp(Double.valueOf(str2));
						area.setText("");
						sign = "-";
					}
				} else if (sign == "ln") { 
   
					if (str2.length() == 0) { 
   
						sign = "-";
					} else { 
   
						temp = Math.log(Double.valueOf(str2));
						area.setText("");
						sign = "-";
					}
				}
			} else if (str == "*") { 
   
				if (sign == " ") { 
   
					sign = "*";
					temp = Double.valueOf(str2);
					area.setText("");
				} else if (sign == "-") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = temp - Double.valueOf(str2);
						sign = "*";
						area.setText("");
						key = true;
					}
				} else if (sign == "+") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = temp + Double.valueOf(str2);
						sign = "*";
						area.setText("");
						key = true;
					}
				} else if (sign == "*") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = temp * Double.valueOf(str2);
						sign = "*";
						area.setText("");
						key = true;
					}
				} else if (sign == "/") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else if (Double.valueOf(str2) == 0) { 
   
						area.setText("除数不能为0哦！按 C");
					} else { 
   
						temp = temp / Double.valueOf(str2);
						area.setText("");
						sign = "*";
						key = true;
					}
				} else if (sign == "s") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = Math.sqrt(Double.valueOf(str2));
						area.setText("");
						sign = "*";
					}
				} else if (sign == "sin") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = Math.sin(Double.valueOf(str2));
						area.setText("");
						sign = "*";
					}
				} else if (sign == "cos") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = Math.cos(Double.valueOf(str2));
						area.setText("");
						sign = "*";
					}
				} else if (sign == "exp") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = Math.exp(Double.valueOf(str2));
						area.setText("");
						sign = "*";
					}
				} else if (sign == "ln") { 
   
					if (str2.length() == 0) { 
   
						sign = "*";
					} else { 
   
						temp = Math.log(Double.valueOf(str2));
						area.setText("");
						sign = "*";
					}
				}
			} else if (str == "/") { 
   
				if (sign == " ") { 
   
					sign = "/";
					temp = Double.valueOf(str2);
					area.setText("");
				} else if (sign == "-") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = temp - Double.valueOf(str2);
						sign = "/";
						area.setText("");
						key = true;
					}
				} else if (sign == "+") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = temp + Double.valueOf(str2);
						sign = "/";
						area.setText("");
						key = true;
					}
				} else if (sign == "*") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = temp * Double.valueOf(str2);
						sign = "/";
						area.setText("");
						key = true;
					}
				} else if (sign == "/") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else if (Double.valueOf(str2) == 0) { 
   
						area.setText("除数不能为0哦！按 C");
					} else { 
   
						temp = temp / Double.valueOf(str2);
						area.setText("");
						sign = "/";
						key = true;
					}
				} else if (sign == "s") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = Math.sqrt(Double.valueOf(str2));
						area.setText("");
						sign = "/";
					}
				} else if (sign == "sin") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = Math.sin(Double.valueOf(str2));
						area.setText("");
						sign = "/";
					}
				} else if (sign == "cos") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = Math.cos(Double.valueOf(str2));
						area.setText("");
						sign = "/";
					}
				} else if (sign == "exp") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = Math.exp(Double.valueOf(str2));
						area.setText("");
						sign = "/";
					}
				} else if (sign == "ln") { 
   
					if (str2.length() == 0) { 
   
						sign = "/";
					} else { 
   
						temp = Math.log(Double.valueOf(str2));
						area.setText("");
						sign = "/";
					}
				}
			} else if (str == "=") { 
   
				if (sign == "+") { 
   
					if (str2.length() == 0) { 
   
						area.setText(String.valueOf(temp));
						sign = " ";
					} else { 
   
						temp = temp + Double.valueOf(str2);
						area.setText(String.valueOf(temp));
						sign = " ";
					}
				} else if (sign == "-") { 
   
					if (str2.length() == 0) { 
   
						area.setText(String.valueOf(temp));
						sign = " ";
					} else { 
   
						temp = temp - Double.valueOf(str2);
						area.setText(String.valueOf(temp));
						sign = " ";
					}
				} else if (sign == "*") { 
   
					if (str2.length() == 0) { 
   
						area.setText(String.valueOf(temp));
						sign = " ";
					} else { 
   
						temp = temp * Double.valueOf(str2);
						area.setText(String.valueOf(temp));
						sign = " ";
					}
				} else if (sign == "/") { 
   
					if (Double.valueOf(str2) == 0) { 
   
						area.setText("除数不能为0哦！按C");
						sign = " ";
					} else { 
   
						temp = temp / Double.valueOf(str2);
						area.setText(String.valueOf(temp));
						sign = " ";
					}
				} else if (sign == " ") { 
   
					if (str2.length() == 0) { 
   
						area.setText(String.valueOf(temp));
					} else { 
   
						temp = Double.valueOf(str2);
						area.setText(String.valueOf(temp));
					}
				} else if (sign == "s") { 
   
					temp = Math.sqrt(Double.valueOf(str2));
					area.setText(String.valueOf(temp));
					sign = " ";
				} else if (sign == "sin") { 
   
					temp = Math.sin(Double.valueOf(str2));
					area.setText(String.valueOf(temp));
					sign = " ";
				} else if (sign == "cos") { 
   
					temp = Math.cos(Double.valueOf(str2));
					area.setText(String.valueOf(temp));
					sign = " ";
				} else if (sign == "exp") { 
   
					temp = Math.exp(Double.valueOf(str2));
					area.setText(String.valueOf(temp));
					sign = " ";
				} else if (sign == "ln") { 
   
					temp = Math.log(Double.valueOf(str2));
					area.setText(String.valueOf(temp));
					sign = " ";
				}
				key = true;
			}
		}
	}
}