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Java生成驗證碼
- package cn.net.seek.util;
-
- import java.awt.Color;
- import java.awt.Font;
- import java.awt.Graphics;
- import java.awt.image.BufferedImage;
- import java.io.IOException;
- import java.io.OutputStream;
- import java.util.Random;
-
- import javax.imageio.ImageIO;
-
- public class ImgZoom {
-
- // 驗證碼圖片中可以出現的字符集,可根據需要修改
- private char mapTable[] = { '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', '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', '0', '1', '2', '3', '4', '5', '6', '7', '8',
- '9' };
-
-
- /**
- * 生成驗證碼
- * @param width 寬度 60
- * @param height 高度 24
- * @param os 輸出流
- * @return 生成的隨機字符串
- */
- public String getCertPic(int width, int height, OutputStream os) {
- BufferedImage image = new BufferedImage(width, height,
- BufferedImage.TYPE_INT_RGB);
- // 獲取圖形上下文
- Graphics g = image.getGraphics();
-
- // 生成隨機類
- Random random = new Random();
-
- // 設定背景色
- // g.setColor(getRandColor(200, 250)); //隨機生成背景色
- g.setColor(new Color(255, 255, 255));
- g.fillRect(0, 0, width, height);
-
- // 設定字體
- g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
-
- // 隨機產生155條干擾線,使圖象中的認證碼不易被其它程序探測到
- g.setColor(getRandColor(160, 200));
- for (int i = 0; i < 155; i++) {
- int x = random.nextInt(width);
- int y = random.nextInt(height);
- int xl = random.nextInt(12);
- int yl = random.nextInt(12);
- g.drawLine(x, y, x + xl, y + yl);
- }
-
- // 取隨機產生的認證碼(5位)
- String sRand = "";
- for (int i = 0; i < 5; i++) {
- String rand = mapTable[(int) (mapTable.length * Math.random())]
- + "";
- sRand += rand;
- // 將認證碼顯示到圖象中
- g.setColor(new Color(20 + random.nextInt(110), 20 + random
- .nextInt(110), 20 + random.nextInt(110)));// 調用函數出來的顏色相同,可能是因為種子太接近,所以只能直接生成
- g.drawString(rand, 10 * i + 3, (int) (Math.random() * 9 + 14));// 14-23 Math.round(Math.random()*(Max-Min)+Min)
- }
- // 釋放圖形上下文
- g.dispose();
- try {
- // 輸出圖象到頁面
- ImageIO.write(image, "JPEG", os);
- } catch (IOException e) {
- return "";
- }
- return sRand;
- }
-
- Color getRandColor(int fc, int bc) {
- // 給定范圍獲得隨機顏色
- Random random = new Random();
- 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);
- }
-
- }
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