GridLayout布局

//JFrameClass.java
import java.awt.*;
import javax.swing.*;

public class JFrameClass extends JFrame{
	String[] str={"0","1","2","3","4","5","6","7","8","9","+","-","*","/","="};
	JButton[] button;
	JPanel panel1,panel2;
	JTextField text;
	public JFrameClass(){
		super("GrayLayout");
		button = new JButton[15];
		panel1 = new JPanel();
		panel2 = new JPanel();
		getContentPane().add(panel1,"North");
		getContentPane().add(panel2,"Center");
		text = new JTextField(15);
		panel1.add(text);
		panel2.setLayout(new GridLayout(5,3));
		
		for(int i = 0;i<15;i++){
			button[i] = new JButton(str[i]);
			panel2.add(button[i]);
		}
		setSize(200,300);
		setVisible(true);
		setResizable(false);
	}
}

//test.java
import javax.swing.*;

public class test {
	public static void main(String[] args){
		JFrameClass frame = new JFrameClass();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	
}