大家好,又见面了,我是你们的朋友全栈君。
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
public class VerifyCode {
private int w = 70;
private int h = 35;
private Random r = new Random();
// 定义有那些字体
private String[] fontNames = { "宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312" };
// 定义有那些验证码的随机字符
private String codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ";
// 生成背景色
private Color bgColor = new Color(250, 250, 250);
// 用于gettext 方法 获得生成的验证码文本
private String text;
// 生成随机颜色
private Color randomColor() {
int red = r.nextInt(150);
int green = r.nextInt(150);
int blue = r.nextInt(150);
return new Color(red, green, blue);
}
// 生成随机字体
private Font randomFont() {
int index = r.nextInt(fontNames.length);
String fontName = fontNames[index];
int style = r.nextInt(4);
int size = r.nextInt(5) + 24;
return new Font(fontName, style, size);
}
// 画干扰线
private void drawLine(BufferedImage image) {
int num = 3;
Graphics2D g2 = (Graphics2D) image.getGraphics();
for (int i = 0; i < num; i++) {
int x1 = r.nextInt(w);
int y1 = r.nextInt(h);
int x2 = r.nextInt(w);
int y2 = r.nextInt(h);
g2.setStroke(new BasicStroke(1.5F));// 不知道
g2.setColor(Color.blue);
g2.drawLine(x1, y1, x2, y2);
}
}
// 得到codes的长度内的随机数 并使用charAt 取得随机数位置上的codes中的字符
private char randomChar() {
int index = r.nextInt(codes.length());
return codes.charAt(index);
}
// 创建一张验证码的图片
public BufferedImage createImage() {
BufferedImage image = new BufferedImage(w, h,
BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = (Graphics2D) image.getGraphics();
StringBuilder sb = new StringBuilder();
// 向图中画四个字符
for (int i = 0; i < 4; i++) {
String s = randomChar() + "";
sb.append(s);
float x = i * 1.0F * w / 4;
g2.setFont(randomFont());
g2.setColor(randomColor());
g2.drawString(s, x, h - 5);
}
this.text = sb.toString();
drawLine(image);
// 返回图片
return image;
}
// 得到验证码的文本 后面是用来和用户输入的验证码 检测用
public String getText() {
return text;
}
// 定义输出的对象和输出的方向
public static void output(BufferedImage bi, OutputStream fos)
throws FileNotFoundException, IOException {
ImageIO.write(bi, "JPEG", fos);
}
}
以上,就生成了一个验证码。
写一个test,生成指定的验证码图像jpg
public class test {
public static void main(String[] args) throws IOException {
VerifyCode code = new VerifyCode();
BufferedImage image = code.createImage();
ImageIO.write(image,"jpg",new File("F:/image.jpg"));
}
}
当然,也可以在servlet里生成。
@WebServlet(urlPatterns="/VerifyCodeServlet.do")
public class VerifyCodeServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
VerifyCode code = new VerifyCode();
BufferedImage image = code.createImage();
ImageIO.write(image,"jpg",response.getOutputStream());
}
}
然后展示在.html或.jsp里
<img src="VerifyCodeServlet.do">
发布者:全栈程序员-用户IM,转载请注明出处:https://javaforall.cn/159571.html原文链接:https://javaforall.cn
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