图片验证码工具类

浅浅的花香味﹌ 2021-11-23 23:58 357阅读 0赞

[.java文件下载地址][.java]

package gh.util;
    
    
    import java.awt.Color;
    import java.awt.Font;
    import java.awt.Graphics;
    import java.awt.Graphics2D;
    import java.awt.image.BufferedImage;
    import java.io.BufferedReader;
    import java.io.FileInputStream;
    import java.io.FileReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Random;
    
    import javax.imageio.ImageIO;
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class ImageUtil {
        
    
    	public static void createImage(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
        
    		// 禁止缓存
    		// response.setHeader("Cache-Control", "no-cache");
    		// response.setHeader("Pragma", "no-cache");
    		// response.setDateHeader("Expires", -1);
    
    		int width = 120;
    		int height = 25;
    
    		// 步骤一 绘制一张内存中图片
    		BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    
    		// 步骤二 图片绘制背景颜色 ---通过绘图对象
    		Graphics graphics = bufferedImage.getGraphics();// 得到画图对象 --- 画笔
    		// 绘制任何图形之前 都必须指定一个颜色
    		graphics.setColor(getRandColor(200, 250));
    		graphics.fillRect(0, 0, width, height);
    
    		// 步骤三 绘制边框
    		graphics.setColor(Color.WHITE);
    		graphics.drawRect(0, 0, width - 1, height - 1);
    
    		// 步骤四 四个随机数字
    		Graphics2D graphics2d = (Graphics2D) graphics;
    		// 设置输出字体
    		graphics2d.setFont(new Font("宋体", Font.BOLD, 18));
    
    		Random random = new Random();// 生成随机数
    		String words = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
    
    		// 定义x坐标
    		int x = 10;
    		String word = "";
    		for (int i = 0; i < 4; i++) {
        
    			int index = random.nextInt(words.length());
    			// 随机颜色
    			graphics2d
    					.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
    			// 旋转 -30 --- 30度
    			int jiaodu = random.nextInt(60) - 30;
    			// 换算弧度
    			double theta = jiaodu * Math.PI / 180;
    
    			// 获得字母数字
    			char c = words.charAt(index);
    			word += c;
    			// 将c 输出到图片
    			graphics2d.rotate(theta, x, 20);
    			graphics2d.drawString(String.valueOf(c), x, 20);
    			graphics2d.rotate(-theta, x, 20);
    			x += 30;
    		}
    
    		System.out.println(word);
    		// 将验证码内容保存session
    		request.getSession().setAttribute("checkcode_session", word);
    
    		// 步骤五 绘制干扰线
    		graphics.setColor(getRandColor(160, 200));
    		int x1;
    		int x2;
    		int y1;
    		int y2;
    		for (int i = 0; i < 30; i++) {
        
    			x1 = random.nextInt(width);
    			x2 = random.nextInt(12);
    			y1 = random.nextInt(height);
    			y2 = random.nextInt(12);
    			graphics.drawLine(x1, y1, x1 + x2, x2 + y2);
    		}
    
    		// 将上面图片输出到浏览器 ImageIO
    		graphics.dispose();// 释放资源
    		ImageIO.write(bufferedImage, "jpg", response.getOutputStream());
    
    	}
    
    	/**
    	 * 取其某一范围的color
    	 * 
    	 * @param fc int 范围参数1
    	 * @param bc int 范围参数2
    	 * @return Color
    	 */
    	private static Color getRandColor(int fc, int bc) {
        
    		// 取其随机颜色
    		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);
    	}
    
    }

[.java]: https://download.csdn.net/download/weixin_42591732/11437719