//备选汉字的长度 int length = base.length(); //创建内存图像 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 获取图形上下文 Graphics g = image.getGraphics(); //创建随机类的实例 Random random = new Random(); // 设定图像背景色(因为是做背景,所以偏淡) g.setColor(getRandColor(random, 200, 250)); g.fillRect(0, 0, width, height); //备选字体 String[] fontTypes = { "\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66"}; int fontTypesLength = fontTypes.length; //在图片背景上增加噪点 g.setColor(getRandColor(random, 160, 200)); g.setFont(new Font("Times New Roman", Font.PLAIN, 14)); for (int i = 0; i < 6; i++) { g.drawString("*********************************************", 0, 5 * (i + 2)); } //取随机产生的认证码(6个汉字) //保存生成的汉字字符串 String sRand = ""; for (int i = 0; i < 6; i++) { int start = random.nextInt(length); String rand = base.substring(start, start + 1); sRand += rand; //设置字体的颜色 g.setColor(getRandColor(random, 10, 150)); //设置字体 g.setFont(new Font(fontTypes[random.nextInt(fontTypesLength)], Font.BOLD, 18 + random.nextInt(6))); //将此汉字画到图片上 g.drawString(rand, 24 * i + 10 + random.nextInt(8), 24); } //将认证码存入session session.setAttribute("rand", sRand); g.dispose(); //输出图象到页面 ImageIO.write(image, "JPEG", response.getOutputStream()); %> |