|  Welcome to JShell -- Version 11.0.7
|  For an introduction type: /help intro

jshell> import java.awt.*

jshell> import javax.swing.*

jshell> var jf = new JFrame("graphics")
jf ==> javax.swing.JFrame[frame0,95,0,0x0,invalid,hidden ... tPaneCheckingEnabled=true]

jshell> jf.setVisible(true)

jshell> jf.setSize(400, 400)

jshell> var g = jf.getGraphics()
g ==> sun.java2d.SunGraphics2D[font=java.awt.Font[famil ... java.awt.SystemColor[i=9]]

jshell> g.drawLine(0,0, 30,30)

jshell> g.drawLine(200,200, 300,300)

jshell> g.drawLine(0,0, 50,50)

jshell> var b = new JButton("A")
b ==> javax.swing.JButton[,0,0,0x0,invalid,alignmentX=0 ... ext=A,defaultCapable=true]

jshell> jf.add(b, BorderLayout.EAST)

jshell> g.drawLine(200,200, 400,400)

jshell> g.drawRect(200,200, 200,200)

jshell> g.fillRect(200,200, 200,200)

jshell>