diff --git a/Cal.java b/Cal.java
new file mode 100644
index 0000000000000000000000000000000000000000..cdce5a3a86d1cc68d709bb892843adf501ba2b1e
--- /dev/null
+++ b/Cal.java
@@ -0,0 +1,177 @@
+package java2020spring;
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.*;
+public class Cal extends JFrame implements ActionListener {
+	/**
+	 * 
+	 */
+   private static final long serialVersionUID = 7234416171012693398L;
+   private final String[] Butt = { "Back", "C" };
+   private final String[] Keys = { "/","sqrt" , "7", "8", "9","+", "4", "5", "6", "-", "1", "2", "3","*","0",".","=", "1/x" };
+   private JButton butts[] = new JButton[Butt.length];
+   private JButton keys[] = new JButton[Keys.length];
+   private JTextField resultText = new JTextField("0");
+   private boolean firstNum = true;
+   private boolean operateValidFlag = true;
+   private double resultNum = 0.0;
+   private String operator = "=";
+   
+	private double getNumberFromText() {
+		double result = 0.0;
+		try {
+			result = Double.valueOf(resultText.getText()).doubleValue();
+		} 
+		catch (NumberFormatException e) {}
+		return result;
+	}
+	/*计算器界面布置*/
+	public Cal() {
+		setTitle("Java计算器");
+		setBackground(Color.LIGHT_GRAY);
+		setBounds(500, 150,350,350);
+		setResizable(true);
+		JMenuBar menuB = new JMenuBar();
+		JMenu menu1=new JMenu("查看(V)");
+		JMenu menu2=new JMenu("编辑(E)");
+		JMenu menu3=new JMenu("帮助(H)");
+		JMenu menu4=new JMenu("计算器类型");
+		menuB.add(menu1);
+		menuB.add(menu2);
+		menuB.add(menu3);
+		menuB.add(menu4);
+		setJMenuBar(menuB);
+		JMenuItem menuI = new JMenuItem("标准型计算器");
+		menu4.add(menuI);
+		resultText.setHorizontalAlignment(JTextField.RIGHT);
+		resultText.setBackground(Color.LIGHT_GRAY);
+		resultText.setFont(new Font("Courir",Font.BOLD,30));
+		JPanel Panel1 = new JPanel();
+		Panel1.setLayout(new GridLayout(5, 4, 3, 3));
+		for (int i = 0; i < Butt.length; i++) {
+			butts[i] = new JButton(Butt[i]);
+			Panel1.add(butts[i]);
+			butts[i].setFont(new Font("Courir",Font.ITALIC,17));
+		}
+		for (int i = 0; i < Keys.length; i++) {
+			keys[i] = new JButton(Keys[i]);
+			Panel1.add(keys[i]);
+			keys[i].setFont(new Font("Courir",Font.PLAIN,18));
+		}
+		keys[16].setBackground(Color.pink);
+		JPanel panel1 = new JPanel();
+		panel1.setLayout(new BorderLayout(3,3));
+		panel1.add("Center", Panel1);
+		JPanel panel2 = new JPanel();
+		panel2.setLayout(new BorderLayout());
+		panel2.add("Center", resultText);
+		getContentPane().setLayout(new BorderLayout(3, 5));
+		getContentPane().add("North", panel2);
+		getContentPane().add("Center", panel1);
+		/*添加监听器*/
+		for (int i = 0; i < Keys.length; i++) {
+			keys[i].addActionListener(this);
+		}
+		for (int i = 0; i < Butt.length; i++) {
+			butts[i].addActionListener(this);
+		}
+	}
+	/*不同事件的处理*/
+	public void actionPerformed(ActionEvent e) {
+		String lab = e.getActionCommand();
+		if (lab.equals(Butt[0])) {
+			handleBack();
+		} 
+		else if (lab.equals(Butt[1])) {
+			handleC();
+		} 
+		else if ("0123456789.".indexOf(lab) >= 0) {
+			handleNumber(lab);
+		} 
+		else
+			handleOperator(lab);
+	}
+	/*回退处理*/
+	private void handleBack() {
+		String text = resultText.getText();
+		int i = text.length();
+		if (i > 0) {
+			text = text.substring(0, i - 1);
+			if (text.length() == 0) {
+				resultText.setText("0");
+				firstNum = true;
+				operator = "=";
+			}
+			else
+				resultText.setText(text);
+		}
+	}
+	/*清空处理*/
+	private void handleC() {
+		resultText.setText("0");
+		firstNum = true;
+		operator = "=";
+	}
+	/*数字字符处理*/
+	private void handleNumber(String key) {
+		if (firstNum) {
+			resultText.setText(key);
+		}
+		else if (key.equals(".")) {
+			resultText.setText(resultText.getText() + ".");
+		}
+		else if (!key.equals(".")) {
+			resultText.setText(resultText.getText() + key);
+		}
+		firstNum = false;
+	}
+	/*运算处理*/
+	private void handleOperator(String key) {
+		if (operator.equals("/")) {
+			if (getNumberFromText() == 0.0) {
+				operateValidFlag = false;
+				resultText.setText("除数不能为零!");
+			}
+			else 
+				resultNum= resultNum/getNumberFromText();
+		} 
+		else if (operator.equals("1/x")) {
+			if (resultNum == 0.0) {
+				operateValidFlag = false;
+				resultText.setText("零没有倒数!");
+			}
+			else
+				resultNum = 1 / resultNum;
+			}
+	    else if (operator.equals("+")) {
+		    resultNum += getNumberFromText();
+	}
+	    else if (operator.equals("-")) {
+		    resultNum -= getNumberFromText();
+	}
+		else if (operator.equals("*")) {
+			resultNum *= getNumberFromText();
+		}
+		else if (operator.equals("sqrt")) {
+			resultNum = Math.sqrt(resultNum);
+		}
+		else if (operator.equals("=")) {
+			resultNum = getNumberFromText();
+		}
+		if (operateValidFlag) {
+			long m1;
+			double m2;
+			m1 = (long) resultNum;
+			m2 = resultNum - m1;
+			if (m2 == 0) {
+				resultText.setText(String.valueOf (m1));
+			}
+			else {
+				resultText.setText(String.valueOf(resultNum));
+			}
+		}
+		operator = key;
+		firstNum = true;
+		operateValidFlag = true;
+	}
+}
diff --git a/Calmain.java b/Calmain.java
new file mode 100644
index 0000000000000000000000000000000000000000..372c806621b131215d2b04e9e728809625f8a4a8
--- /dev/null
+++ b/Calmain.java
@@ -0,0 +1,9 @@
+package java2020spring;
+import javax.swing.JFrame;
+public class Calmain {
+public static void main(String args[]) {
+	Cal Win = new Cal();
+	Win.setVisible(true);
+	Win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+   }
+}
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