Java弱智计算器

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class J_SimpleComputer {
	static JTextField text1=new JTextField("",10);
	static JTextField text2=new JTextField("",10);
	static JTextField text3=new JTextField("",10);
	static JComboBox operator=new JComboBox();
	static char []oper={'+','-','*','/','='};
	static void Init()
	{
		for(int i=0;i<4;i++)
		{
			operator.addItem(oper[i]);
		}
	}
	static JButton deng=new JButton("=");
	static String plus="+",minus="-",multi="*",divide="/",result;
	static int tmp;	
	public static void main(String args[])
	{			
		Init();
		JFrame win=new JFrame("计算器");
		win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		win.setLayout(new FlowLayout());
		win.setBounds(600,200,500,100);
		win.add(text1);
		win.add(operator);
		win.add(text2);
		win.add(deng);
		win.add(text3);
		deng.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent e)
			{
				String x=text1.getText();
				String y=text2.getText();
				int a=Integer.parseInt(x);
				int b=Integer.parseInt(y);
				String op=operator.getSelectedItem().toString();
				if(op.equals(divide))
				{
					if(b==0)
					{
						JOptionPane.showMessageDialog(null,"除0错误！");
					}
					else
					{
						tmp=a/b;
						result=Integer.toString(tmp);
						text3.setText(result);
					}			
				}
				else if(op.equals(multi)) 
				{
					tmp=a*b;
					result=Integer.toString(tmp);
					text3.setText(result);
				}
				else if(op.equals(plus)) 
				{
					tmp=a+b;
					result=Integer.toString(tmp);
					text3.setText(result);
				}
				else
				{
					tmp=a-b;
					result=Integer.toString(tmp);
					text3.setText(result);
				}
			}
		});				
		win.setVisible(true);
	}
}