1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8" %>
2
3 <%
4 String action = request.getParameter("action");
5 String safecodeText = request.getParameter("safecodeTest");
6 if("action".equals(action)){
7 String safecode = (String)session.getAttribute("safecode");
8 if(safecode.equals(safecodeText)){
9 out.print("验证码正确！");
10 }else{
11 out.print("验证码错误！请重新输入！");
12 }
13 }
14 %>
15 <html>
16 <head>
17 <title>验证码测试</title>
18 </head>
19
20 <body>
21 <form action="servlet/demo" method="post">
22 <input type="hidden" name="action" value="action"/>
23 <img alt="验证码" src="servlet/demo">
24 <input type="text" name="safecodeTest">
25 <input type="submit" value="go">
26 </form>
27 </body>
28 </html>
1 import java.io.*;
2
3 import javax.servlet.*;
4 import javax.servlet.http.*;
5 import java.util.Random;
6 import java.awt.*;
7 import java.awt.image.*;
8 import javax.imageio.*;
9
10
11 public class demo extends HttpServlet {
12 //产生随即的字体
13 private Font getFont() {
14 Random random = new Random();
15 Font font[] = new Font[5];
16 font[0] = new Font("Ravie", Font.PLAIN, 24);
17 font[1] = new Font("Antique Olive Compact", Font.PLAIN, 24);
18 font[2] = new Font("Forte", Font.PLAIN, 24);
19 font[3] = new Font("Wide Latin", Font.PLAIN, 24);
20 font[4] = new Font("Gill Sans Ultra Bold", Font.PLAIN, 24);
21 return font[random.nextInt(5)];
22 }
23
24 protected void doGet(HttpServletRequest req, HttpServletResponse resp)
25 throws ServletException, IOException {
26 // 设置响应头 Content-type类型
27 resp.setContentType("image/jpeg");
28 // 以下三句是用于设置页面不缓存
29 resp.setHeader("Pragma", "No-cache");
30 resp.setHeader("Cache-Control", "No-cache");
31 resp.setDateHeader("Expires", 0);
32
33 OutputStream os = resp.getOutputStream();
34 int width = 83, height = 30;
35 // 建立指定宽、高和BufferedImage对象
36 BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
37
38 Graphics g = image.getGraphics(); // 该画笔画在image上
39 Color c = g.getColor(); // 保存当前画笔的颜色，用完画笔后要回复现场
40 g.fillRect(0, 0, width, height);
41
42
43 char[] ch = "abcdefghjkmnpqrstuvwxyz23456789".toCharArray(); // 随即产生的字符串 不包括 i l(小写L) o（小写O） 1（数字1）0(数字0)
44 int length = ch.length; // 随即字符串的长度
45 String sRand = ""; // 保存随即产生的字符串
46 Random random = new Random();
47 for (int i = 0; i < 4; i++) {
48 // 设置字体
49 g.setFont(getFont());
50 // 随即生成0-9的数字
51 String rand = new Character(ch[random.nextInt(length)]).toString();
52 sRand += rand;
53 // 设置随机颜色
54 g.setColor(new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255)));
55 g.drawString(rand, 20 * i + 6, 25);
56 }
57 //产生随即干扰点
58 for (int i = 0; i < 20; i++) {
59 int x1 = random.nextInt(width);
60 int y1 = random.nextInt(height);
61 g.drawOval(x1, y1, 2, 2);
62 }
63 g.setColor(c); // 将画笔的颜色再设置回去
64 g.dispose();
65
66 //将验证码记录到session
67 req.getSession().setAttribute("safecode", sRand);
68 // 输出图像到页面
69 ImageIO.write(image, "JPEG", os);
70
71 }
72
73 protected void doPost(HttpServletRequest req, HttpServletResponse resp)
74 throws ServletException, IOException {
75 doGet(req, resp);
76 }
77
78 }
1 <?xml version="1.0" encoding="UTF-8"?>
2 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
3 <display-name>JavaWebDemo</display-name>
4 <servlet>
5 <description>This is the description of my J2EE component</description>
6 <display-name>This is the display name of my J2EE component</display-name>
7 <servlet-name>demo</servlet-name>
8 <servlet-class>demo</servlet-class>
9 </servlet>
10
11 <servlet-mapping>
12 <servlet-name>demo</servlet-name>
13 <url-pattern>/servlet/demo</url-pattern>
14 </servlet-mapping>
15
16 <welcome-file-list>
17 <welcome-file>index.html</welcome-file>
18 <welcome-file>index.htm</welcome-file>
19 <welcome-file>index.jsp</welcome-file>
20 <welcome-file>default.html</welcome-file>
21 <welcome-file>default.htm</welcome-file>
22 <welcome-file>default.jsp</welcome-file>
23 </welcome-file-list>
24 </web-app>
1 package action;
2
3 import java.awt.Color;
4 import java.awt.Font;
5 import java.awt.Graphics;
6 import java.awt.image.BufferedImage;
7 import java.io.ByteArrayInputStream;
8 import java.io.ByteArrayOutputStream;
9 import java.util.Map;
10
11 import javax.imageio.ImageIO;
12 import javax.imageio.stream.ImageOutputStream;
13
14 import com.opensymphony.xwork2.ActionContext;
15 import com.opensymphony.xwork2.ActionSupport;
16
17 public class ImageAction extends ActionSupport {
18
19 /**
20 *
21 */
22 private static final long serialVersionUID = 1L;
23 private ByteArrayInputStream inputStream;
24 public String createRandomString(){
25 String str="";
26 for(int i=0;i<4;i++){
27 str+=Integer.toString((new Double(Math.random()*10)).intValue());
28 }
29 return str;
30 }
31 public Color createRandomColor(){
32 int r=(new Double(Math.random()*256)).intValue();
33 int g=(new Double(Math.random()*256)).intValue();
34 int b=(new Double(Math.random()*256)).intValue();
35 return new Color(r,g,b);
36 }
37 public BufferedImage createImage(String str){
38 int width=60;
39 int height=22;
40 BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
41 Graphics g=image.getGraphics();
42 g.setColor(Color.WHITE);
43 g.fillRect(0, 0, width, height);
44 g.setColor(Color.BLACK);
45 g.drawRect(0, 0, width-1, height-1);
46 g.setFont(new Font("Atlantic Inline",Font.PLAIN,18));
47 g.setColor(this.createRandomColor());
48 g.drawString(Character.toString(str.charAt(0)), 8, 17);
49 g.drawString(Character.toString(str.charAt(1)), 20, 17);
50 g.drawString(Character.toString(str.charAt(2)), 33, 17);
51 g.drawString(Character.toString(str.charAt(3)), 45, 17);
52 g.dispose();
53 return image;
54 }
55 public ByteArrayInputStream createInputStream() throws Exception{
56 String str=this.createRandomString();
57 BufferedImage image=this.createImage(str);
58 ActionContext actioncontext=ActionContext.getContext();
59 Map session=actioncontext.getSession();
60 session.put("random", str);
61 ByteArrayOutputStream output=new ByteArrayOutputStream();
62 ImageOutputStream imageout=ImageIO.createImageOutputStream(output);
63 ImageIO.write(image, "JPEG", imageout);
64 imageout.close();
65 ByteArrayInputStream input=new ByteArrayInputStream(output.toByteArray());
66 output.close();
67 return input;
68 }
69 public String execute() throws Exception{
70 setInputStream(createInputStream());
71 return SUCCESS;
72 }
73 public ByteArrayInputStream getInputStream(){
74 return inputStream;
75 }
76 public void setInputStream(ByteArrayInputStream inputStream){
77 this.inputStream=inputStream;
78 }
79 }
