1 package com.jiangbei.verifycodeutils;
2
3 import java.awt.BasicStroke;
4 import java.awt.Color;
5 import java.awt.Font;
6 import java.awt.Graphics2D;
7 import java.awt.image.BufferedImage;
8 import java.io.IOException;
9 import java.io.OutputStream;
10 import java.util.Random;
11
12 import javax.imageio.ImageIO;
13
14 public class VerifyCode {
15
16 private int w = 70;
17
18 private int h = 35;
19
20 private Random r = new Random();
21
22 // {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}
23
24 private String[] fontNames = {"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312"};
25
26 // 可选字符
27
28 private String codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";
29
30 // 背景色
31
32 private Color bgColor = new Color(255, 255, 255);
33
34 // 验证码上的文本
35
36 private String text ;
37
38 // 生成随机的颜色
39
40 private Color randomColor () {
41
42 int red = r.nextInt(150);
43
44 int green = r.nextInt(150);
45
46 int blue = r.nextInt(150);
47
48 return new Color(red, green, blue);
49
50 }
51
52 // 生成随机的字体
53
54 private Font randomFont () {
55
56 int index = r.nextInt(fontNames.length);
57
58 String fontName = fontNames[index];//生成随机的字体名称
59
60 int style = r.nextInt(4);//生成随机的样式, 0(无样式), 1(粗体), 2(斜体), 3(粗体+斜体)
61
62 int size = r.nextInt(5) + 24; //生成随机字号, 24 ~ 28
63
64 return new Font(fontName, style, size);
65
66 }
67
68 // 画干扰线
69
70 private void drawLine (BufferedImage image) {
71
72 int num = 3;//一共画3条
73
74 Graphics2D g2 = (Graphics2D)image.getGraphics();
75
76 for(int i = 0; i < num; i++) {//生成两个点的坐标，即4个值
77
78 int x1 = r.nextInt(w);
79
80 int y1 = r.nextInt(h);
81
82 int x2 = r.nextInt(w);
83
84 int y2 = r.nextInt(h);
85
86 g2.setStroke(new BasicStroke(1.5F));
87
88 g2.setColor(Color.BLUE); //干扰线是蓝色
89
90 g2.drawLine(x1, y1, x2, y2);//画线
91
92 }
93
94 }
95
96 // 随机生成一个字符
97
98 private char randomChar () {
99
100 int index = r.nextInt(codes.length());
101
102 return codes.charAt(index);
103
104 }
105
106 // 创建BufferedImage
107
108 private BufferedImage createImage () {
109
110 BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
111
112 Graphics2D g2 = (Graphics2D)image.getGraphics();
113
114 g2.setColor(this.bgColor);
115
116 g2.fillRect(0, 0, w, h);
117
118 return image;
119
120 }
121
122 // 调用这个方法得到验证码
123
124 public BufferedImage getImage () {
125
126 BufferedImage image = createImage();//创建图片缓冲区
127
128 Graphics2D g2 = (Graphics2D)image.getGraphics();//得到绘制环境
129
130 StringBuilder sb = new StringBuilder();//用来装载生成的验证码文本
131
132 // 向图片中画4个字符
133
134 for(int i = 0; i < 4; i++) {//循环四次，每次生成一个字符
135
136 String s = randomChar() + "";//随机生成一个字母
137
138 sb.append(s); //把字母添加到sb中
139
140 float x = i * 1.0F * w / 4; //设置当前字符的x轴坐标
141
142 g2.setFont(randomFont()); //设置随机字体
143
144 g2.setColor(randomColor()); //设置随机颜色
145
146 g2.drawString(s, x, h-5); //画图
147
148 }
149
150 this.text = sb.toString(); //把生成的字符串赋给了this.text
151
152 drawLine(image); //添加干扰线
153
154 return image;
155
156 }
157
158 // 返回验证码图片上的文本
159
160 public String getText () {
161
162 return text;
163
164 }
165
166 // 保存图片到指定的输出流
167
168 public static void output (BufferedImage image, OutputStream out)
169
170 throws IOException {
171
172 ImageIO.write(image, "JPEG", out);
173
174 }
175
176 }
简单运用：
1 package com.day11.servlet;
2
3 import java.awt.image.BufferedImage;
4 import java.io.IOException;
5
6 import javax.servlet.ServletException;
7 import javax.servlet.http.HttpServlet;
8 import javax.servlet.http.HttpServletRequest;
9 import javax.servlet.http.HttpServletResponse;
10
11 import com.jiangbei.verifycodeutils.VerifyCode;
12 /**
13 * 用于验证码案例
14 * @author jiangbei01
15 *
16 */
17 public class VerifyCodeServlet extends HttpServlet {
18
19
20
21 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
22 /**
23 * 生成图片
24 * 保存图片上验证码文本到session域中
25 * 将图片响应给客户端
26 */
27 VerifyCode vc = new VerifyCode();
28 BufferedImage image = vc.getImage();
29 request.getSession().setAttribute("vcode", vc.getText());
30
31 VerifyCode.output(image, response.getOutputStream());
32
33 }