Java生成验证码小工具
无意中看到一个生成简易验证码的小工具类(保存学习):
工具类代码:
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1 import java.awt.BasicStroke; 2 import java.awt.Color; 3 import java.awt.Font; 4 import java.awt.Graphics2D; 5 import java.awt.image.BufferedImage; 6 import java.io.IOException; 7 import java.io.OutputStream; 8 import java.util.Random; 9 10 import javax.imageio.ImageIO; 11 12 public class VerifyCode { 13 private int w = 70; 14 private int h = 35; 15 private Random r = new Random(); 16 // {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"} 17 private String[] fontNames = {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}; 18 // 可选字符 19 private String codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ"; 20 // 背景色 21 private Color bgColor = new Color(255, 255, 255); 22 // 验证码上的文本 23 private String text ; 24 25 // 生成随机的颜色 26 private Color randomColor () { 27 int red = r.nextInt(150); 28 int green = r.nextInt(150); 29 int blue = r.nextInt(150); 30 return new Color(red, green, blue); 31 } 32 33 // 生成随机的字体 34 private Font randomFont () { 35 int index = r.nextInt(fontNames.length); 36 String fontName = fontNames[index];//生成随机的字体名称 37 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) 38 int size = r.nextInt(5) + 24; //生成随机字号, 24 ~ 28 39 return new Font(fontName, style, size); 40 } 41 42 // 画干扰线 43 private void drawLine (BufferedImage image) { 44 int num = 5;//一共画5条 45 Graphics2D g2 = (Graphics2D)image.getGraphics(); 46 for(int i = 0; i < num; i++) {//生成两个点的坐标,即4个值 47 int x1 = r.nextInt(w); 48 int y1 = r.nextInt(h); 49 int x2 = r.nextInt(w); 50 int y2 = r.nextInt(h); 51 g2.setStroke(new BasicStroke(1.5F)); 52 g2.setColor(randomColor()); //随机生成干扰线颜色 53 g2.drawLine(x1, y1, x2, y2);//画线 54 } 55 } 56 57 // 随机生成一个字符 58 private char randomChar () { 59 int index = r.nextInt(codes.length()); 60 return codes.charAt(index); 61 } 62 63 // 创建BufferedImage 64 private BufferedImage createImage () { 65 BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); 66 Graphics2D g2 = (Graphics2D)image.getGraphics(); 67 g2.setColor(this.bgColor); 68 g2.fillRect(0, 0, w, h); 69 return image; 70 } 71 72 // 调用这个方法得到验证码 73 public BufferedImage getImage () { 74 BufferedImage image = createImage();//创建图片缓冲区 75 Graphics2D g2 = (Graphics2D)image.getGraphics();//得到绘制环境 76 StringBuilder sb = new StringBuilder();//用来装载生成的验证码文本 77 // 向图片中画4个字符 78 for(int i = 0; i < 4; i++) {//循环四次,每次生成一个字符 79 String s = randomChar() + "";//随机生成一个字母 80 sb.append(s); //把字母添加到sb中 81 float x = i * 1.0F * w / 4; //设置当前字符的x轴坐标 82 g2.setFont(randomFont()); //设置随机字体 83 g2.setColor(randomColor()); //设置随机颜色 84 g2.drawString(s, x, h-5); //画图 85 } 86 this.text = sb.toString(); //把生成的字符串赋给了this.text 87 drawLine(image); //添加干扰线 88 return image; 89 } 90 91 // 返回验证码图片上的文本 92 public String getText () { 93 return text; 94 } 95 96 // 保存图片到指定的输出流 97 public static void output (BufferedImage image, OutputStream out) 98 throws IOException { 99 ImageIO.write(image, "JPEG", out); 100 } 101 }
测试代码:
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import java.awt.image.BufferedImage; import java.io.FileOutputStream; import org.junit.Test; public class Demo2 { @Test public void fun1() throws Exception { VerifyCode verifyCode = new VerifyCode(); BufferedImage bi = verifyCode.getImage(); System.out.println(verifyCode.getText()); VerifyCode.output(bi, new FileOutputStream("F:/b.jpg")); } }
运行结果: