SpringMVC下获取验证码实例详解

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
/**
   * 生成验证码
   * @param request
   * @param response
   */
  @RequestMapping(value = "login/getVerifyCode")
  public void getVerifyCode(HttpServletRequest request,HttpServletResponse response){
    response.setHeader("Pragma","No-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.setDateHeader("Expires", 0);
    response.setContentType("image/jpeg");

    //生成随机字符串
    String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
    //存入Session, 此处可以根据自己的需求
    HttpSession session = request.getSession();
    session.setAttribute("verifyCode",verifyCode);
    //生成图片
    int w = 100, h = 35;
    try {
      //将图片写入到 response 的输出流即可将图片返回到客户端了
      VerifyCodeUtils.outputImage(w, h , response.getOutputStream(), verifyCode);
    } catch (IOException e) {
      logger.error("生成验证码失败, Cause by: {}", e.getMessage(), e);
    }
  }

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

/**
 * 生成图片流
 * @Description: Created by zcqshine on 2017/5/18.
 */
public class VerifyCodeUtils {
  private static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
  private static Random random = new Random();

  /**
   * 使用系统默认字符源生成验证码
   * @param verifySize  验证码长度
   * @return
   */
  public static String generateVerifyCode(int verifySize){
    return generateVerifyCode(verifySize, VERIFY_CODES);
  }

  /**
   * 使用指定源生成验证码
   * @param verifySize  验证码长度
   * @param sources    验证码字符源
   * @return
   */
  public static String generateVerifyCode(int verifySize, String sources){
    if (sources == null || sources.trim().length() == 0){
      sources = VERIFY_CODES;
    }

    int codesLen = sources.length();
    Random rand = new Random(System.currentTimeMillis());
    StringBuilder verifyCode = new StringBuilder(verifySize);
    for (int i = 0; i < verifySize; i++){
      verifyCode.append(sources.charAt(rand.nextInt(codesLen -1 )));
    }
    return verifyCode.toString();
  }

  /**
   * 输出随机验证码图片流, 并返回验证码值
   * @param w
   * @param h
   * @param outputFile
   * @param verifySize
   * @return
   */
  public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException{
    String verifyCode = generateVerifyCode(verifySize);
    outputImage(w,h,outputFile,verifyCode);
    return verifyCode;
  }

  /**
   * 生成指定验证码图像文件
   * @param w
   * @param h
   * @param outputFile
   * @param verifyCode
   * @throws IOException
   */
  public static void outputImage(int w, int h, File outputFile, String verifyCode) throws IOException{
    if (outputFile == null){
      return;
    }
    File dir = outputFile.getParentFile();
    if(!dir.exists()){
      dir.mkdirs();
    }

    try {
      outputFile.createNewFile();
      FileOutputStream fos = new FileOutputStream(outputFile);
      outputImage(w, h, fos, verifyCode);
      fos.close();
    } catch (IOException e) {
      throw e;
    }
  }

  public static void outputImage(int w, int h, OutputStream os, String code) throws IOException{
    int verifySize = code.length();
    BufferedImage image = new BufferedImage(w,h, BufferedImage.TYPE_INT_RGB);
    Random rand = new Random();
    Graphics2D g2 = image.createGraphics();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
    Color[] colors = new Color[5];
    Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN, Color.GRAY,
        Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
        Color.PINK, Color.YELLOW};
    float[] fractions = new float[colors.length];
    for (int i = 0; i < colors.length; i++){
      colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
      fractions[i] = rand.nextFloat();
    }
    Arrays.sort(fractions);

    g2.setColor(Color.GRAY);  //设置边框色
    g2.fillRect(0,0, w, h);

    Color c = getRandColor(200, 250);
    g2.setColor(c); //设置背景色
    g2.fillRect(0, 2, w, h-4);

    //绘制干扰线
    Random random = new Random();
    g2.setColor(getRandColor(160, 200));// 设置线条的颜色
    for (int i = 0; i < 20; i++) {
      int x = random.nextInt(w - 1);
      int y = random.nextInt(h - 1);
      int xl = random.nextInt(6) + 1;
      int yl = random.nextInt(12) + 1;
      g2.drawLine(x, y, x + xl + 40, y + yl + 20);
    }

    // 添加噪点
    float yawpRate = 0.05f;// 噪声率
    int area = (int) (yawpRate * w * h);
    for (int i = 0; i < area; i++) {
      int x = random.nextInt(w);
      int y = random.nextInt(h);
      int rgb = getRandomIntColor();
      image.setRGB(x, y, rgb);
    }

    shear(g2, w, h, c);// 使图片扭曲

    g2.setColor(getRandColor(100, 160));
    int fontSize = h-4;
    Font font = new Font("Algerian", Font.ITALIC, fontSize);
    g2.setFont(font);
    char[] chars = code.toCharArray();
    for(int i = 0; i < verifySize; i++){
      AffineTransform affine = new AffineTransform();
      affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize/2, h/2);
      g2.setTransform(affine);
      g2.drawChars(chars, i, 1, ((w-10) / verifySize) * i + 5, h/2 + fontSize/2 - 10);
    }

    g2.dispose();
    ImageIO.write(image, "jpg", os);

  }

  private static Color getRandColor(int fc, int bc) {
    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);
  }

  private static int getRandomIntColor() {
    int[] rgb = getRandomRgb();
    int color = 0;
    for (int c : rgb) {
      color = color << 8;
      color = color | c;
    }
    return color;
  }

  private static int[] getRandomRgb() {
    int[] rgb = new int[3];
    for (int i = 0; i < 3; i++) {
      rgb[i] = random.nextInt(255);
    }
    return rgb;
  }

  private static void shear(Graphics g, int w1, int h1, Color color) {
    shearX(g, w1, h1, color);
    shearY(g, w1, h1, color);
  }

  private static void shearX(Graphics g, int w1, int h1, Color color) {

    int period = random.nextInt(2);

    boolean borderGap = true;
    int frames = 1;
    int phase = random.nextInt(2);

    for (int i = 0; i < h1; i++) {
      double d = (double) (period >> 1)
          * Math.sin((double) i / (double) period
          + (6.2831853071795862D * (double) phase)
          / (double) frames);
      g.copyArea(0, i, w1, 1, (int) d, 0);
      if (borderGap) {
        g.setColor(color);
        g.drawLine((int) d, i, 0, i);
        g.drawLine((int) d + w1, i, w1, i);
      }
    }

  }

  private static void shearY(Graphics g, int w1, int h1, Color color) {

    int period = random.nextInt(40) + 10; // 50;

    boolean borderGap = true;
    int frames = 20;
    int phase = 7;
    for (int i = 0; i < w1; i++) {
      double d = (double) (period >> 1)
          * Math.sin((double) i / (double) period
          + (6.2831853071795862D * (double) phase)
          / (double) frames);
      g.copyArea(i, 0, 1, h1, 0, (int) d);
      if (borderGap) {
        g.setColor(color);
        g.drawLine(i, (int) d, i, 0);
        g.drawLine(i, (int) d + h1, i, h1);
      }
    }
  }

public static void main(String[] args) {
    File dir = new File("/Users/zcqshine/Downloads/test");
    int w = 200, h= 80;
    for (int i = 0; i< 50; i++){
      String verifyCode = generateVerifyCode(4);
      File file = new File(dir, verifyCode + ".jpg");
      try {
        outputImage(w, h, file, verifyCode);
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }
}