Since Java Applet runs on JVM (Java virtual machine) of browser, and its data is in embedded server, server dispatches data through TCP socket, and Java Applet takes over them by I/O stream and draws curves.

• 由于Java Applet运行于浏览器的Java虚拟机上，无法直接取得服务器端数据，因此，服务器端通过TCP Socket发送数据，由Java Apptet使用I/O流读取数据，并绘制曲线。