java怎么样控制jpanel空间的的大小，和位置

import org.javabuilders.layout.Size;

import javax.swing.*;
import javax.swing.text.AbstractDocument;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

/**
* Created by IntelliJ IDEA.
* User: DELL
* Date: 11-11-7
* Time: 下午2:40
* To change this template use File | Settings | File Templates.
*/
public class MyDear extends JFrame{
static JFrame frame = new JFrame("我是窗口");
static JButton button = new JButton("按钮");
static JPanel panel = new JPanel();
public static void main(String[] args) {
frame.setBounds(0,0,300,300);
Container contain = frame.getContentPane();
panel.add(button);
panel.setBackground(Color.green);
panel.setPreferredSize(new Dimension(100,200));
contain.add(panel,BorderLayout.NORTH);
frame.setVisible(true);
}
}

设置大小可以用this.setBounds(500,600);或者this.Size(500,600);或者用setPreferredSize(new Dimension(100,200));来设置固定的大小
位置可以用this.setLocation(200,300);来设置