用JAVA实现画线，不是直线，而是点住鼠标左键划到哪里哪里就画线，就

import java.awt.BasicStroke;import java.awt.BorderLayout;import java.awt.Color;import java.awt.FlowLayout;import java.awt.Frame;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.Label;import java.awt.Panel;import java.awt.event.MouseAdap