diff --git a/src/java2020spring/MyCalculator.java b/src/java2020spring/MyCalculator.java
new file mode 100644
index 0000000000000000000000000000000000000000..7a034744dd8063c0b4b4a0da5b9248157b711e21
--- /dev/null
+++ b/src/java2020spring/MyCalculator.java
@@ -0,0 +1,269 @@
+
+package firstcalculator;
+
+import java.awt.Color;
+import java.awt.GridLayout;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.math.BigDecimal;
+import java.text.SimpleDateFormat;
+
+import javax.swing.JButton;
+import javax.swing.JFrame;
+import javax.swing.JOptionPane;
+import javax.swing.JPanel;
+import javax.swing.JTextField;
+
+
+public class MyCalculator extends JFrame{
+	//用于判断是否重新开始
+	private boolean start = true;
+	private double result = 0;
+	//存放加减乘除等于等
+	private String command = "=";
+	private JTextField jTextField;
+	private JPanel jPanel = new JPanel();
+	private JButton[] jButtons;
+	
+	//用构造方法进行必要的设置
+	public MyCalculator() {
+		
+		this.setTitle("科学计算器");
+		this.setSize(600, 300);
+		this.setLocationRelativeTo(null);
+		
+		//添加文本域
+		jTextField = new JTextField(30);
+		jTextField.setText("");
+		jTextField.setEditable(true);
+		this.add(jTextField,"North");
+		
+		//添加按钮
+		jPanel.setLayout(new GridLayout(5,7,3,3));
+		String name[] = {
+				"+/-","PI","1/X","C","/","*","Back","X^2","X^3",
+				"X^y","7","8","9","-","X!","√X","3^√X","4","5",
+				"6","+","sin","cos","tan","1","2","3","%",
+				"2进制","10进制","cot","time","0",".","="
+		};
+		jButtons = new JButton[name.length];
+		MyActionListener actionListener= new MyActionListener();
+		
+		//利用循环创建按钮对象并添加事件监听器
+		for(int i = 0; i < name.length; i++) {
+			
+			jButtons[i] = new JButton(name[i]);
+			jButtons[i].addActionListener(actionListener);
+			
+			//设置按钮背景颜色
+			jButtons[i].setBackground(Color.lightGray);
+			if(name[i].equals("="))
+				jButtons[i].setBackground(Color.RED);
+			else if((int)name[i].charAt(0)>=48 && (int)name[i].charAt(0)<=57 
+					&& name[i].length() == 1)
+				jButtons[i].setBackground(Color.WHITE);
+			else if(name[i].equals("Back"))
+				jButtons[i].setBackground(Color.GRAY);
+			
+			jPanel.add(jButtons[i]);
+		}
+		
+		this.add(jPanel);
+		this.setDefaultCloseOperation(EXIT_ON_CLOSE);
+		this.setVisible(true);
+		
+	}
+	
+	//用内部类实现事件监听器
+	class MyActionListener implements ActionListener{
+		//按钮被单击
+		public void actionPerformed(ActionEvent e) {
+			
+			String input = e.getActionCommand();
+			//开始
+			if(start) {
+				if((int)input.charAt(0)>=48 && (int)input.charAt(0)<=57
+						&& input.length() == 1 ) {
+					jTextField.setText(""+input);
+				}
+				if(input.equals("+/-")) {
+					jTextField.setText("-");				
+				}
+				if(input.equals("PI")) {
+					jTextField.setText(""+Math.PI);
+				}
+					start = false;
+				if(input.equals("C"))
+					jTextField.setText("");
+			} 
+			//0~9数字等非运算符
+			else if((int)input.charAt(0)>=48 && (int)input.charAt(0)<=57
+					&& input.length() == 1 || input.equals(".")){
+				jTextField.setText(jTextField.getText()+input);
+			}
+			//实现所有 数组+运算符 的运算 
+			
+			//实现清零键
+			else if(input.equals("C"))
+				jTextField.setText("");
+			//实现退格键
+			else if(input.equals("Back")) {
+				if(jTextField.getText().length() > 0){
+					jTextField.setText(jTextField.getText().substring(0,jTextField.getText().length()-1));
+				}
+			}
+			//实现正弦三角函数
+			else if(input.equals("sin")) {
+				result = Math.sin(Double.parseDouble(jTextField.getText()));
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现余弦三角函数
+			else if(input.equals("cos")) {
+				result = Math.cos(Double.parseDouble(jTextField.getText()));
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现余切三角函数
+			else if(input.equals("cot")) {
+				result = 1.0/Math.tan(Double.parseDouble(jTextField.getText()));
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现正切三角函数
+			else if(input.equals("tan")) {
+				result = Math.tan(Double.parseDouble(jTextField.getText()));
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现十进制到二进制的转化
+			else if(input.equals("2进制")) {
+				String result2 = Integer.toBinaryString(Integer.parseInt(jTextField.getText()));
+				jTextField.setText(""+getPrettyNumber(result2));
+				start = true;
+			}
+			//实现二进制到十进制的转化
+			else if(input.equals("10进制")) {
+				try {
+					String result2 = Integer.valueOf(jTextField.getText(),2).toString();
+					jTextField.setText(""+getPrettyNumber(result2));
+				}catch(NumberFormatException exception) {
+					JOptionPane.showMessageDialog(null, "对不起，数字错误，请重新输入！", "Error!", JOptionPane.ERROR_MESSAGE);
+					throw new NumberFormatException("数字格式错误");
+				}finally {
+					start = true;
+				}
+				
+			}
+			//实现1/x
+			else if(input.equals("1/X")) {
+				result = 1 / Double.parseDouble(jTextField.getText());
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现平方计算
+			else if(input.equals("X^2")) {
+				result = Math.pow(Double.parseDouble(jTextField.getText()), 2);
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现立方计算
+			else if(input.equals("X^3")) {
+				result = Math.pow(Double.parseDouble(jTextField.getText()), 3);
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现阶乘 
+			else if(input.equals("X!")) {
+				if(Double.parseDouble(jTextField.getText()) < 0) {
+					JOptionPane.showMessageDialog(null, "对不起，阶乘计算不能为负数", "Error!", JOptionPane.ERROR_MESSAGE);
+					jTextField.setText("对不起，阶乘计算不能为负数");
+					start = true;
+					throw new IllegalArgumentException("阶乘计算出现负数");
+				}else {
+					int sum;
+					sum = factorial(Integer.parseInt(jTextField.getText()));
+					jTextField.setText(Integer.toString(sum));
+					start = true;
+				}
+
+			}
+			//实现百分号计算
+			else if(input.equals("%")) {
+				result = Double.parseDouble(jTextField.getText())/ 100.0;
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;	
+			}
+			//实现开平方根
+			else if(input.equals("√X")) {
+				result = Math.sqrt(Double.parseDouble(jTextField.getText()));
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现开立方根
+			else if(input.equals("3^√X")) {
+				result = Math.pow(Double.parseDouble(jTextField.getText()),1.0/3);
+				jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+				start = true;
+			}
+			//实现获取当前时间
+			else if(input.equals("time")) {
+				SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+				jTextField.setText(df.format(System.currentTimeMillis()));
+				start = true;
+			}
+			
+			//实现加减乘除等 数字+运算符+数字 形式的运算
+			else {
+				if(!start) {
+					
+					if(command.equals("+"))
+						result += Double.parseDouble(jTextField.getText());
+					else if(command.equals("-"))
+						result -= Double.parseDouble(jTextField.getText());
+					else if(command.equals("*"))
+						result *= Double.parseDouble(jTextField.getText());
+					else if(command.equals("/")) {
+						if(Double.parseDouble(jTextField.getText()) != 0) {
+							result /= Double.parseDouble(jTextField.getText());
+							}else {
+								jTextField.setText(""+"对不起，除数不能为零");
+								JOptionPane.showMessageDialog(null, "对不起，除数不能为零", "Error!", JOptionPane.ERROR_MESSAGE);
+								command = "=";
+								start = true;
+								throw new ArithmeticException("除数为零");
+							}
+						
+					}
+					else if(command.equals("=")) 
+						result = Double.parseDouble(jTextField.getText());
+						
+					else if(command.equals("X^y"))
+						result = Math.pow(result, Double.parseDouble(jTextField.getText()));
+					jTextField.setText(""+getPrettyNumber(Double.toString(result)));
+					command = input;
+					start = true;
+				}
+			}
+			}
+	}
+	//去掉小数点后没用的0
+    public static String getPrettyNumber(String number) {
+        return BigDecimal.valueOf(Double.parseDouble(number))
+                .stripTrailingZeros().toPlainString();
+    }
+	//用循环计算阶乘
+    public static int factorial(int num) {
+    	int sum = 1;
+        for(int i = 1;i <= num; i++){
+            sum *= i;
+        }
+        return sum;
+    }
+    
+	public static void main(String[] args) {
+		MyCalculator myCalculator = new MyCalculator();
+
+	}
+
+}