Java Graphics2D drawRect 抛出“sg2d.loops”是 null

Question

java.lang.NullPointerException: Cannot read field "fillParallelogramLoop" because "sg2d.loops" is null
        at java.desktop/sun.java2d.pipe.LoopPipe.fillParallelogram(LoopPipe.java:355)
        at java.desktop/sun.java2d.pipe.PixelToParallelogramConverter.drawGeneralLine(PixelToParallelogramConverter.java:287)
        at java.desktop/sun.java2d.pipe.PixelToParallelogramConverter.drawLine(PixelToParallelogramConverter.java:80)
        at java.desktop/sun.java2d.pipe.PixelToParallelogramConverter.drawRect(PixelToParallelogramConverter.java:103)
        at java.desktop/sun.java2d.SunGraphics2D.drawRect(SunGraphics2D.java:2410)

I just used Graphics2D to draw something on the BufferedImage.

Answer 1

I solved this problem through the synchronous lock.