JSP随机验证图片如何制作

2024-09-05 00:22:16

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这篇文章主要介绍了JSP随机验证图片是如何制作的，感兴趣的朋友可以参考一下

小编整理了一篇关于模仿腾讯随机验证图片的文章。下面直接上代码吧!一个Java 类和一个JSP 页面。

Java类代码：

以下是JSP模仿腾讯随机验证图片引用片段：

package icewee.image;

import java.awt.BasicStroke;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics2D;

import java.awt.RenderingHints;

import java.awt.geom.Line2D;

import java.awt.image.BufferedImage;

import java.util.Random;

public class TokenUtil {

private static final String base = "23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefhijklmnpqrstuvwxyz";

private static final int length = base.length();

public static BufferedImage createTokenImage(int width, int height,

String randomCode) {

BufferedImage image = new BufferedImage(width, height,

BufferedImage.TYPE_INT_RGB);

Graphics2D g = image.createGraphics();

Random random = new Random();

g.setColor(new Color(230, 230, 250)); // 设置背景色

g.fillRect(0, 0, width, height); // 填充背景

g.setColor(Color.BLACK);

// 绘制边缘

g.drawRect(-1, -1, width + 1, height + 1);

g.setColor(Color.GRAY);

// 设置字体,随机选择字体,暂设置8种字体

Font font = new Font((new String[] { "Arial", "Arial Black",

"Arial Italic", "Courier New", "Courier New Bold Italic",

"Courier New Italic", "Franklin Gothic Medium",

"Franklin Gothic Medium Italic" })[random.nextInt(8)],

Font.PLAIN, 30);

// g.setStroke(new BasicStroke((float)(Math.random()),

// BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));

g.setFont(font);

// 定义字体颜色范围

int red = random.nextInt(160), green = random.nextInt(50), blue = random

.nextInt(50);

// 定义一个无干扰线区间和一个起始位置

int nor = random.nextInt(50), rsta = random.nextInt(131);

// 绘制干扰正弦曲线 M:曲线平折度, D:Y轴常量 V:X轴焦距

int M = random.nextInt(15) + 5, D = random.nextInt(23) + 15, V = random

.nextInt(5) + 1;

double x = 0.0;

double y = M * Math.sin(Math.toRadians(V * x)) + D;

double px, py;

for (int i = 0; i < 131; i++) {

px = x + 1;

py = M * Math.sin(Math.toRadians(V * px)) + D;

if (rsta < i && i < (rsta + nor))

g.setColor(new Color(230, 230, 250));

else

g.setColor(new Color(red, green, blue));

// 随机设置像素点宽带(线宽)

g.setStroke(new BasicStroke((float) (Math.random() + 1.5f)));

g.draw(new Line2D.Double(x, y, px, py));

x = px;

y = py;

}

char[] codes = randomCode.toCharArray();

for (int i = 0; i < codes.length; i++) {

// 旋转图形

int degree = (random.nextInt(20) - 10) % 360;

double ang = degree * 0.0174532925; // 将角度转为弧度

g.rotate(ang, width / 2, height / 2);

g.setColor(new Color(red, green, blue));

g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,

RenderingHints.VALUE_ANTIALIAS_ON);

int gr = random.nextInt(8);

g.drawString(String.valueOf(codes[i]), 24 * i + 10 + gr, 38);

}

g.dispose();

return image;

}

public static String createRandomCode(int size, int width, int height) {

StringBuffer randomCode = new StringBuffer();

for (int i = 0; i < size; i++) {

Random random = new Random();

int start = random.nextInt(length);

String strRand = base.substring(start, start + 1);

randomCode.append(strRand);

}

return randomCode.toString();

}

}

JSP页面：

以下是JSP模仿腾讯随机验证图片代码引用片段：

<%@ page contentType="image/jpeg" pageEncoding="GBK"%>

<%@ page import="java.awt.image.BufferedImage" %>

<%@page import="javax.imageio.ImageIO" %>

<%@ page import="com.icesoft.image.TokenUtil" %>

<%

//设置页面不缓存

response.setHeader("Pragma", "No-cache");

response.setHeader("Cache-Control", "no-cache");

response.setDateHeader("Expires", 0);

int width = 120, height = 50;

String randomCode = TokenUtil.createRandomCode(4, width, height);

System.out.println("生成的随机码：" + randomCode);

BufferedImage image = TokenUtil.createTokenImage(width, height, randomCode);

ImageIO.write(image, "JPEG", response.getOutputStream());

response.flushBuffer();

out.clear();

out = pageContext.pushBody();

%>