自己封装的一个java图片验证码

原文：http://www.cnblogs.com/chiangchou/p/VCodeGenerator.html

验证码生成器：

  1 package com.lz.Tools;
  2 
  3 import java.awt.Color;
  4 import java.awt.Font;
  5 import java.awt.Graphics;
  6 import java.awt.Graphics2D;
  7 import java.awt.image.BufferedImage;
  8 import java.util.Random;
  9 
 10 /**
 11  * 验证码生成器
 12  * 
 13  * @author bojiangzhou
 14  */
 15 public class VCodeGenerator {
 16     
 17     /**
 18      * 验证码来源
 19      */
 20     final private char[] code = {
 21         '2', '3', '4', '5', '6', '7', '8', '9',
 22         'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
 23         'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 
 24         'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F',
 25         'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R',
 26         'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
 27     };
 28     /**
 29      * 字体
 30      */
 31     final private String[] fontNames = new String[]{
 32             "黑体", "宋体", "Courier", "Arial", 
 33             "Verdana", "Times", "Tahoma", "Georgia"};
 34     /**
 35      * 字体样式
 36      */
 37     final private int[] fontStyles = new int[]{
 38             Font.BOLD, Font.ITALIC|Font.BOLD
 39     };
 40     
 41     /**
 42      * 验证码长度
 43      * 默认4个字符
 44      */
 45     private int vcodeLen = 4;
 46     /**
 47      * 验证码图片字体大小
 48      * 默认17
 49      */
 50     private int fontsize = 21;
 51     /**
 52      * 验证码图片宽度
 53      */
 54     private int width = (fontsize+1)*vcodeLen+10;
 55     /**
 56      * 验证码图片高度
 57      */
 58     private int height = fontsize+12;
 59     /**
 60      * 干扰线条数
 61      * 默认3条
 62      */
 63     private int disturbline = 3;
 64     
 65     
 66     public VCodeGenerator(){}
 67     
 68     /**
 69      * 指定验证码长度
 70      * @param vcodeLen 验证码长度
 71      */
 72     public VCodeGenerator(int vcodeLen) {
 73         this.vcodeLen = vcodeLen;
 74         this.width = (fontsize+1)*vcodeLen+10;
 75     }
 76     
 77     /**
 78      * 生成验证码图片
 79      * @param vcode 要画的验证码
 80      * @param drawline 是否画干扰线
 81      * @return
 82      */
 83     public BufferedImage generatorVCodeImage(String vcode, boolean drawline){
 84         //创建验证码图片
 85         BufferedImage vcodeImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
 86         Graphics g = vcodeImage.getGraphics();
 87         //填充背景色
 88         g.setColor(new Color(246, 240, 250));
 89         g.fillRect(0, 0, width, height);
 90         if(drawline){
 91             drawDisturbLine(g);
 92         }
 93         //用于生成伪随机数
 94         Random ran = new Random();
 95         //在图片上画验证码
 96         for(int i = 0;i < vcode.length();i++){
 97             //设置字体
 98             g.setFont(new Font(fontNames[ran.nextInt(fontNames.length)], fontStyles[ran.nextInt(fontStyles.length)], fontsize));
 99             //随机生成颜色
100             g.setColor(getRandomColor());
101             //画验证码
102             g.drawString(vcode.charAt(i)+"", i*fontsize+10, fontsize+5);
103         }
104         //释放此图形的上下文以及它使用的所有系统资源
105         g.dispose();
106         
107         return vcodeImage;
108     }
109     /**
110      * 获得旋转字体的验证码图片
111      * @param vcode
112      * @param drawline 是否画干扰线
113      * @return
114      */
115     public BufferedImage generatorRotateVCodeImage(String vcode, boolean drawline){
116         //创建验证码图片
117         BufferedImage rotateVcodeImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
118         Graphics2D g2d = rotateVcodeImage.createGraphics();
119         //填充背景色
120         g2d.setColor(new Color(246, 240, 250));
121         g2d.fillRect(0, 0, width, height);
122         if(drawline){
123             drawDisturbLine(g2d);
124         }
125         //在图片上画验证码
126         for(int i = 0;i < vcode.length();i++){
127             BufferedImage rotateImage = getRotateImage(vcode.charAt(i));
128             g2d.drawImage(rotateImage, null, (int) (this.height * 0.7) * i, 0);
129         }
130         g2d.dispose();
131         return rotateVcodeImage;
132     }
133     /**
134      * 生成验证码
135      * @return 验证码
136      */
137     public String generatorVCode(){
138         int len = code.length;
139         Random ran = new Random();
140         StringBuffer sb = new StringBuffer();
141         for(int i = 0;i < vcodeLen;i++){
142             int index = ran.nextInt(len);
143             sb.append(code[index]);
144         }
145         return sb.toString();
146     }
147     /**
148      * 为验证码图片画一些干扰线
149      * @param g 
150      */
151     private void drawDisturbLine(Graphics g){
152         Random ran = new Random();
153         for(int i = 0;i < disturbline;i++){
154             int x1 = ran.nextInt(width);
155             int y1 = ran.nextInt(height);
156             int x2 = ran.nextInt(width);
157             int y2 = ran.nextInt(height);
158             g.setColor(getRandomColor());
159             //画干扰线
160             g.drawLine(x1, y1, x2, y2);
161         }
162     }
163     /**
164      * 获取一张旋转的图片
165      * @param c 要画的字符
166      * @return
167      */
168     private BufferedImage getRotateImage(char c){
169         BufferedImage rotateImage = new BufferedImage(height, height, BufferedImage.TYPE_INT_ARGB);
170         Graphics2D g2d = rotateImage.createGraphics();
171         //设置透明度为0
172         g2d.setColor(new Color(255, 255, 255, 0));
173         g2d.fillRect(0, 0, height, height);
174         Random ran = new Random();
175         g2d.setFont(new Font(fontNames[ran.nextInt(fontNames.length)], fontStyles[ran.nextInt(fontStyles.length)], fontsize));
176         g2d.setColor(getRandomColor());
177         double theta = getTheta();
178         //旋转图片
179         g2d.rotate(theta, height/2, height/2);
180         g2d.drawString(Character.toString(c), (height-fontsize)/2, fontsize+5);
181         g2d.dispose();
182         
183         return rotateImage;
184     }
185     /**
186      * @return 返回一个随机颜色
187      */
188     private Color getRandomColor(){
189         Random ran = new Random();
190         return new Color(ran.nextInt(220), ran.nextInt(220), ran.nextInt(220)); 
191     }
192     /**
193      * @return 角度
194      */
195     private double getTheta(){
196         return ((int) (Math.random()*1000) % 2 == 0 ? -1 : 1)*Math.random();
197     }
198 
199     /**
200      * @return 验证码字符个数
201      */
202     public int getVcodeLen() {
203         return vcodeLen;
204     }
205     /**
206      * 设置验证码字符个数
207      * @param vcodeLen
208      */
209     public void setVcodeLen(int vcodeLen) {
210         this.width = (fontsize+3)*vcodeLen+10;
211         this.vcodeLen = vcodeLen;
212     }
213     /**
214      * @return 字体大小
215      */
216     public int getFontsize() {
217         return fontsize;
218     }
219     /**
220      * 设置字体大小
221      * @param fontsize
222      */
223     public void setFontsize(int fontsize) {
224         this.width = (fontsize+3)*vcodeLen+10;
225         this.height = fontsize+15;
226         this.fontsize = fontsize;
227     }
228     /**
229      * @return 图片宽度
230      */
231     public int getWidth() {
232         return width;
233     }
234     /**
235      * 设置图片宽度
236      * @param width
237      */
238     public void setWidth(int width) {
239         this.width = width;
240     }
241     /**
242      * @return 图片高度
243      */
244     public int getHeight() {
245         return height;
246     }
247     /**
248      * 设置图片高度
249      * @param height 
250      */
251     public void setHeight(int height) {
252         this.height = height;
253     }
254     /**
255      * @return 干扰线条数
256      */
257     public int getDisturbline() {
258         return disturbline;
259     }
260     /**
261      * 设置干扰线条数
262      * @param disturbline
263      */
264     public void setDisturbline(int disturbline) {
265         this.disturbline = disturbline;
266     }
267     
268 }

在servlet里获取验证码：

 1 package com.lz.Servlet;
 2 
 3 import java.awt.image.BufferedImage;
 4 import java.io.IOException;
 5 
 6 import javax.imageio.ImageIO;
 7 import javax.servlet.ServletException;
 8 import javax.servlet.http.HttpServlet;
 9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11 
12 import com.lz.Tools.VCodeGenerator;
13 
14 
15 
16 /**
17  * 获取验证码
18  * @author bojiangzhou
19  *
20  */
21 public class GetVCodeServlet extends HttpServlet {
22 
23     private static final long serialVersionUID = 3259532010990625726L;
24 
25     public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
26         //验证码不能缓存
27         response.setHeader("Expires", "-1");
28         response.setHeader("cache-control", "no-cahce");
29         response.setHeader("pragma", "no-cache");
30         
31         VCodeGenerator vcg = new VCodeGenerator();
32         //取得验证码
33         String vcode = vcg.generatorVCode();
34         //获取验证码图片
35 //        BufferedImage vcodeImage = vcg.generatorRotateVCodeImage(vcode, true);
36         BufferedImage vcodeImage = vcg.generatorVCodeImage(vcode, true);
37         //将验证码保存到session域对象
38         request.getSession().setAttribute("vcode", vcode);
39         //输出验证码图片
40         ImageIO.write(vcodeImage, "gif", response.getOutputStream());
41     }
42     
43 }

前台在img标签里用src获取验证码图片即可

<img class="vcode" src="GetVCodeServlet" />

 

转载于:https://www.cnblogs.com/Bloglwu/p/8744257.html