精简java计算器

[java]代码库

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

/**
 * 精简java计算器
 * 
 */
public class Calculator implements ActionListener {

	private JFrame frame;
	private JButton[] bus;
	private JTextField jtx;
	private JButton bu;
	private char[] strs;
	private String d_one = "";
	private String operator;

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

	/* 利用构造进行实例化 */
	public Calculator() {
		frame = new JFrame("计算器");
		jtx = new JTextField(14);
		bus = new JButton[16];
		strs = "789/456*123-0.+=".toCharArray();
		for (int i = 0; i < 16; i++) {
			bus[i] = new JButton(strs[i] + "");
			bus[i].addActionListener(this);
		}
		bu = new JButton("C");
		bu.addActionListener(this);
		init();
	}

	/* GUI 初始化 */
	public void init() {
		JPanel jp1 = new JPanel();
		jp1.add(jtx);
		jp1.add(bu);
		frame.add(jp1, BorderLayout.NORTH);

		JPanel jp2 = new JPanel();
		jp2.setLayout(new GridLayout(4, 4));
		for (int i = 0; i < 16; i++) {
			jp2.add(bus[i]);
		}

		frame.add(jp2, BorderLayout.CENTER);

		frame.pack();
		frame.setLocation(500, 300);
		frame.setVisible(true);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

	}

	/* 事件的处理 */

	public void actionPerformed(ActionEvent arg0) {
		/* 获取输入字符 */
		String conn = arg0.getActionCommand();
		/* 清除计算器内容 */
		if ("C".equals(conn)) {
			d_one = "";
			operator = "";
			jtx.setText("");
			return;
		}
		/* 暂未实现该功能 */
		if (".".equals(conn)) {
			return;
		}
		/* 记录运算符，保存运算数字 */
		if (("+-*/".indexOf(conn)) != -1) {
			if ("".equals(d_one) && "".equals(jtx.getText()))
				return;
			d_one = jtx.getText();
			operator = conn;
			jtx.setText("");
			return;
		}
		/* 计算结果 */
		if ("=".equals(conn)) {
			if ("".equals(d_one) && "".equals(jtx.getText()))
				return;
			double db = 0;
			if ("+".equals(operator)) {
				db = Double.parseDouble(d_one)
						+ Double.parseDouble(jtx.getText());
				jtx.setText(db + "");
			}
			if ("-".equals(operator)) {
				db = Double.parseDouble(d_one)
						- Double.parseDouble(jtx.getText());
				jtx.setText(db + "");
			}
			if ("*".equals(operator)) {
				db = Double.parseDouble(d_one)
						* Double.parseDouble(jtx.getText());
				jtx.setText(db + "");
			}
			if ("/".equals(operator)) {
				db = Double.parseDouble(d_one)
						/ Double.parseDouble(jtx.getText());
				jtx.setText(db + "");
			}
			d_one = db + "";
			return;
		}
		// 界面显示
		jtx.setText(jtx.getText() + conn);

	}

}

[代码运行效果截图]