300.31输出随机验证码图片

@WebServlet("/FirstServlet")public class FirstServlet extends HttpServlet {private static final long serialVersionUID = 1L;           public static final int WIDTH = 120;    public static final int HEIGHT = 30;    public FirstServlet() {        super();        // TODO Auto-generated constructor stub    }/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);Graphics g = image.getGraphics();//设置背景颜色setBackGround((Graphics2D)g);//设置边框setBorder((Graphics2D)g);//画干扰线setRandomLine((Graphics2D)g);//写随机数drawRandomNum((Graphics2D)g);//图形写给浏览器response.setContentType("image/jpeg");ImageIO.write(image, "jpg", response.getOutputStream());//设置浏览器不要缓存response.setDateHeader("expries", -1);response.setHeader("cache-control", "no-cache");response.setHeader("pragma", "no-cache");}private void drawRandomNum(Graphics2D g) {String base = "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97"+"\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66"+"\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1"+"\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b"+"\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e"+"\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db";g.setColor(Color.RED);g.setFont(new Font("宋体",Font.BOLD,20));int x = 5;for(int i = 0;i<4;i++){int degree = new Random().nextInt()%30; //-30 - 30char ch =base.charAt(new Random().nextInt(base.length()));String st = String.valueOf(ch);g.rotate(degree*Math.PI/180,x,20);g.drawString(st, x, 20);g.rotate(-degree*Math.PI/180,x,20);x += 30;}}private void setRandomLine(Graphics2D g) {g.setColor(Color.GREEN);for(int i = 0;i<3;i++){int x1 = new Random().nextInt(WIDTH);int y1 = new Random().nextInt(HEIGHT);int x2 = new Random().nextInt(WIDTH);int y2 = new Random().nextInt(HEIGHT);g.drawLine(x1, y1, x2, y2);}}private void setBorder(Graphics2D g) {g.setColor(Color.BLUE);g.drawRect(1, 1, WIDTH -2, HEIGHT -2);}private void setBackGround(Graphics2D g) {g.setColor(Color.WHITE);g.fillRect(0, 0, WIDTH, HEIGHT);}protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stub}}