生成验证码页面 报 java.lang.IllegalStateException: getOutputStream() has already been called 解决办法
生成验证码页面核心代码:/**绘图*///step1:创建一个内存映像(画布)BufferedImageimage=newBufferedImage(100,30,BufferedImage.TYPE_INT_RGB);//step2:获得画笔Graphicsg=image.getGraphics();//step3:给画笔设置颜色g.setColor(newColor(255,255,255))