I heavily relied on GridBagLayout (cf. Acknowledgements) to position controls on the figure. Have a look at this other submission, it might save you a great deal of time when designing GUIs manually!

使用swing编程。首先创建一个窗体，并设置默认关闭时关闭，设置大小，设置不可改变大小，设置可显示； 2、创建一个容器，使用GridBagLayout这种布局方式； 3、通过代码在窗体里面实现计算器的界面； 4、通过实现计算器的add()、sub()、multi()、division()、equal()等功能。 -With swing programming. First create a form, and set off by default turned off, set

java中gridbagLayout 的具体用法-the java in gridbagLayout specific usage

swing界面布局器，应用gridBagLayout实现自动布局，-The swing interface layout, automatic layout application gridBagLayout,