一个关于验证码的问题，请各位大虾帮我看下！！！


下面是我的jsp代码，图片信息能显示出来，但就是字符串无法在图片里面显示，请你们帮我看下，到底是哪里出问题了？
<%@ page contentType="image/jpeg" pageEncoding="utf-8"%>
<%@page import="java.awt.*,java.awt.image.*,java.util.*" %>
<%@page import="javax.imageio.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
    </head>
    <body>
        <%
          int width=60,height=20;
          BufferedImage image = 
            new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); 
          Random r = new Random();
          Graphics g = image.getGraphics();
          g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));
          g.fillRect(0, 0, width, height);
          g.setFont(new Font("Times New Roman", Font.PLAIN, 30));
          String[] str={"0","1","2","3","4","5","6","7","8","9",
               "A","B","C","D","E","F","G","F","I","J",
               "K","R","M","N","O","P","Q","R","S","T",
               "U","V","W","X","Y","Z","a","b","c","d",
               "e","f","g","h","i","j","k","l","m","n",
               "o","p","q","r","s","t","u","v","w","x",
               "y","z"};
          String num ="";
          for(int i=0;i<6;i++){
              num = num+str[r.nextInt(62)];
          }
          g.dispose();
          ServletOutputStream sos = response.getOutputStream();
  ImageIO.write(image, "JPEG", sos);
  sos.flush();
  sos.close(); 
        %>
    </body>
</html>

解决方案 »

  1.   

    看到你用num了, 但是没看到你的num写到Graphics中去.
      

  2.   

    写了的，贴的时候可能不小心删了！
     for(int i=0;i <6;i++){ 
                  num = num+str[r.nextInt(62)]; 
              } 
    g.drawString（num，30，20）；
    我都试了好久，也检查了好多遍，就是没看出来是哪错了！！！！！！！
      

  3.   

    在sos.close(); 后加上
    out.clear();
    out = pageContext.pushBody();
    就不会报错 
    不过只有背景没有文字  很奇怪的问题
      我再弄下
      

  4.   


       <body>
            <%
             response.setContentType("image/jpeg");
              int width=60,height=20;
              BufferedImage image =
                new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
              Random r = new Random();
             
              Graphics g = image.getGraphics();
              g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));
              g.fillRect(0, 0, width,height);
              g.setFont(new Font("Times New Roman",Font.PLAIN,18));
              String[] str={"0","1","2","3","4","5","6","7","8","9",
                   "A","B","C","D","E","F","G","F","I","J",
                   "K","R","M","N","O","P","Q","R","S","T",
                   "U","V","W","X","Y","Z","a","b","c","d",
                  "e","f","g","h","i","j","k","l","m","n",
                   "o","p","q","r","s","t","u","v","w","x",
                  "y","z"};
              String num ="";
              for(int i=0;i <4;i++){
    num = num+str[r.nextInt(62)]; 
                  num = num+str;
                  g.setColor(new Color(20+r.nextInt(110),20+r.nextInt(110),20+r.nextInt(110)));
    g.drawString(num,6+10*i,15);
              }
              
             ServletOutputStream sos=response.getOutputStream();
       ImageIO.write(image, "JPEG", sos);
       g.dispose();
    out.clear();
    out = pageContext.pushBody();
    sos.close();
    image=null;
            %>
        </body>
    还需要调试一下 能出来了
      

  5.   

    基本上可以了
      你自己看需求在改改   <body>
            <%
             response.setContentType("image/jpeg");
              int width=60,height=20;
              BufferedImage image =
                new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
              Random r = new Random();
             
              Graphics g = image.getGraphics();
              g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));
              g.fillRect(0, 0, width,height);
             // g.setFont(new Font("Times New Roman",Font.PLAIN,18));
              String[] str={"0","1","2","3","4","5","6","7","8","9",
                   "A","B","C","D","E","F","G","F","I","J",
                   "K","R","M","N","O","P","Q","R","S","T",
                   "U","V","W","X","Y","Z","a","b","c","d",
                  "e","f","g","h","i","j","k","l","m","n",
                   "o","p","q","r","s","t","u","v","w","x",
                  "y","z"};
              String num ="";
              for(int i=0;i <4;i++){
    num = str[r.nextInt(62)]; 
                 // num = num+str;
                  g.setColor(new Color(20+r.nextInt(110),20+r.nextInt(110),20+r.nextInt(110)));
    g.drawString(num,6+13*i, 15);
              }
              
             ServletOutputStream sos=response.getOutputStream();
       ImageIO.write(image, "JPEG", sos);
       g.dispose();
    out.clear();
    out = pageContext.pushBody();
    sos.close();
    image=null;
            %>
        </body>