Swing上关于设置布局管理器的疑问

Question

package com.acconsys.swing.chapter5;

import java.awt.FlowLayout;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Temp {

static final int WIDTH = 300;
static final int HEIGHT = 200;
public static void main(String[] args) {
    JFrame jf = new JFrame("测试程序");
    jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    jf.setSize(WIDTH, HEIGHT);
    jf.setVisible(true);
    JPanel contentJPanel = new JPanel();
    jf.setContentPane(contentJPanel);
    //问题来了,下面这两个在实际代码中任意写一行就行，请问，这两行有啥区别。？？？？？
    contentJPanel.setLayout(new FlowLayout());
    jf.setLayout(new FlowLayout());
}

}

Answer 1

我没有记错的话，默认的布局方式就是FlowLayout的，你不用自己设置。