public class ImageTool{

  private static Random random = new Random();

  public ImageTool() {
  }

  public static Color getRandColor(int fc,int bc){//給定范圍獲得隨機顏色
    if(fc>255) fc=255;
    if(bc>255) bc=255;
    int r=fc+random.nextInt(bc-fc);
    int g=fc+random.nextInt(bc-fc);
    int b=fc+random.nextInt(bc-fc);
    return new Color(r,g,b);
  }

  public static void outputImage(HttpSession session, HttpServletResponse response) throws IOException{

    BufferedImage image = new BufferedImage(60, 20, BufferedImage.TYPE_INT_RGB);
    Graphics g = image.getGraphics();

    g.setColor(getRandColor(200, 250));
    g.fillRect(0, 0, 60, 20);

    g.setFont(new Font("Times New Roman",Font.PLAIN,18));

    g.setColor(getRandColor(160, 200));
    for (int i=0;i<155;i++) {
      int x = random.nextInt(60);
      int y = random.nextInt(20);
      int xl = random.nextInt(12);
      int yl = random.nextInt(12);
      g.drawLine(x,y,x+xl,y+yl);
    }

    StringBuffer randCode = new StringBuffer();
    for (int i=0;i<4;i++){
      String temp = String.valueOf(random.nextInt(10));
      randCode.append(temp);
      g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
      g.drawString(temp,13*i+6,16);
    }
    session.setAttribute("randCode", randCode.toString());

    g.dispose();
    OutputStream out=response.getOutputStream();

    response.reset();
    ImageIO.write(image, "jpg", out);
    out.close();
  }

  public static void imagePut(HttpSession session,OutputStream out,int pWidth,int pHeight,int pSize) throws IOException{

    BufferedImage image = new BufferedImage(pWidth, pHeight, BufferedImage.TYPE_INT_RGB);
    Graphics g = image.getGraphics();

    g.setColor(getRandColor(200, 250));
    g.fillRect(0, 0, pWidth, pHeight);

    g.setFont(new Font("Times New Roman",Font.PLAIN,pSize));

    g.setColor(getRandColor(160, 200));
    for (int i=0;i<18;i++) {
      int x = random.nextInt(60);
      int y = random.nextInt(20);
      int xl = random.nextInt(12);
      int yl = random.nextInt(12);
      g.drawLine(x,y,x+xl,y+yl);
    }

    StringBuffer randCode = new StringBuffer();
    for (int i=0;i<4;i++){
      String temp = String.valueOf(random.nextInt(10));
      randCode.append(temp);
      g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
      g.drawString(temp,13*i+6,16);
    }
    g.dispose();
    ImageIO.write(image, "jpg", out);
    session.setAttribute("randCode", randCode.toString());
//    System.out.println("sessionID："+session.toString()+"； 產生的驗證碼："+session.getAttribute("randCode"));

  }

  public static void imagePutOneColor(HttpSession session,OutputStream out,int pWidth,int pHeight,int pSize) throws IOException{

    BufferedImage image = new BufferedImage(pWidth, pHeight, BufferedImage.TYPE_INT_RGB);
    Graphics g = image.getGraphics();

    g.setColor(new Color(255,255,255));
    g.fillRect(0, 0, 60, 20);

    g.setFont(new Font("Times New Roman",Font.TRUETYPE_FONT,pSize));

    g.setColor(getRandColor(200, 250));
    for (int i=0;i<18;i++) {
      int x = random.nextInt(60);
      int y = random.nextInt(20);
      int xl = random.nextInt(12);
      int yl = random.nextInt(12);
      g.drawLine(x,y,x+xl,y+yl);
    }

    StringBuffer randCode = new StringBuffer();
    for (int i=0;i<4;i++){
      String temp = String.valueOf(random.nextInt(10));
      randCode.append(temp);
      g.setColor(new Color(0,0,0));
      g.drawString(temp,13*i+6,16);
    }
    session.setAttribute("randCode", randCode.toString());

    g.dispose();
    ImageIO.write(image, "jpg", out);
  }

  public static void outputImage(String sessionName, HttpSession session, HttpServletResponse response) throws IOException{

    BufferedImage image = new BufferedImage(60, 20, BufferedImage.TYPE_INT_RGB);
    Graphics g = image.getGraphics();

    g.setColor(getRandColor(200, 250));
    g.fillRect(0, 0, 60, 20);

    g.setFont(new Font("Times New Roman",Font.PLAIN,18));

    g.setColor(getRandColor(160, 200));
    for (int i=0;i<155;i++) {
      int x = random.nextInt(60);
      int y = random.nextInt(20);
      int xl = random.nextInt(12);
      int yl = random.nextInt(12);
      g.drawLine(x,y,x+xl,y+yl);
    }

    StringBuffer randCode = new StringBuffer();
    for (int i=0;i<4;i++){
      String temp = String.valueOf(random.nextInt(10));
      randCode.append(temp);
      g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
      g.drawString(temp,13*i+6,16);
    }
    session.setAttribute(sessionName, randCode.toString());
    g.dispose();
    response.reset();
    OutputStream out=response.getOutputStream();
    ImageIO.write(image, "JPEG", out);

    out.flush();
    out.close();
  }
}