画抛物线和自由落体的小程序，采用的是多线程完成的！-Parabola and the free fall of a small painting program

愤怒的小鸟是一款“亿人迷”的游戏，据说大家喜欢它的原因在于大家喜欢抛物线胜过直线。例题8.15-8.16是笑脸图片直线运动的例子，请修改它的运动轨迹，将它改成抛物线运动。-Angry bird is a million fans, the game, said that everyone likes it because of you like a parabola than a straight line. Example 8.15-8.16 smiley picture examples o

弹出一个对话框，并可以显示抛物线y=x*x的图像，开口向上。-A dialog box pops up, and you can display images parabola y = x* x, and opening up.

一个比较简单的程序，利用java实现如何绘制抛物线-A relatively simple procedure, the use of java realize how to draw a parabola