Java-验证码生成（数字+字母）

import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.Polygon; import java.awt.font.FontRenderContext; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.Random; import javax.imageio.ImageIO; import javafx.geometry.Rectangle2D; /** * 验证码生成 * * @author Administrator * */ public class ValidateCode { // 生成的验证码 String ValidateCode; // 临时文件 File file; char[] value = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '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' }; //获取验证码图片，参数：n:验证码字符数量 public File getValidateCodeImage(int n) throws IOException { //验证码图片尺寸 int width = 25 * n; int height = 30; Font font = new Font("黑体", Font.BOLD, 25); BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g2 = (Graphics2D) bi.getGraphics(); g2.setBackground(Color.WHITE);//背景色 g2.clearRect(0, 0, width, height); g2.setFont(font);//字体 String str = ""; Random random = new Random(); char[] c = new char[n]; //绘制字符 for (int i = 0; i < n; i++) { c[i] = value[random.nextInt(36)]; g2.setColor(getRandColor(0, 255)); g2.drawString(String.valueOf(c[i]), width / n * i, height -5); } str = String.valueOf(c); //绘制线条 for (int i = 0; i < 10; i++) { g2.setPaint(getRandColor(0, 255)); g2.drawLine(random.nextInt(width), random.nextInt(30), random.nextInt(width), random.nextInt(30)); g2.drawPolygon(new Polygon()); } //临时图片路径 file = new File("WebContent/temp/validateCode+" + str + ".jpg"); //输出到临时图像 ImageIO.write(bi, "jpg", file); this.ValidateCode = str; this.file = file; return file; } /** * 获取随机颜色 * @param fc * @param bc * @return */ private Color getRandColor(int fc, int bc) { 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); } /** * 删除临时图片 */ public void destroy() { if (this.file.exists()) { this.file.delete(); } } public String getValidateCode() { return ValidateCode; } public void setValidateCode(String validateCode) { ValidateCode = validateCode; } }

测试：

    ValidateCode v=new ValidateCode();
        File file = v.getValidateCodeImage(4);
        System.out.println(v.getValidateCode());        
        //v.destroy);