JSP随机验证图片如何制作

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();
%>

以上就是jsp 模仿腾讯随机验证图片全部代码，希望对大家的学习有所帮助。