imgcheckcode.java

这是一个用java三层框架做的ISS学员管理系统

package org.pontifex.util.security;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * Copyright: Copyright (c) 2007
 * author Songzou
 * Date: 2007-5-10
 * Time: 11:49:06
 * version 1.0
 */
public class ImgCheckCode {
  private String charRandomCode = "";
  private BufferedImage imageRandomCode;
  private int width;
  private int height;

  public ImgCheckCode(int width, int height) {
    this.width = width;
    this.height = height;
    create(4);
  }

  public ImgCheckCode(int width, int height, int length) {
    this.width = width;
    this.height = height;
    create(length);
  }

  public int getWidth() {
    return width;
  }

  public void setWidth(int width) {
    this.width = width;
  }

  public int getHeight() {
    return height;
  }

  public void setHeight(int height) {
    this.height = height;
  }

  public String getCharRandomCode() {
    return charRandomCode;
  }

  public BufferedImage getImageRandomCode() {
    return imageRandomCode;
  }

  private void create(int length) {
	char[] chr = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9','A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};

    // 在内存中创建图象
    imageRandomCode = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    // 获取图形上下文
    Graphics g = imageRandomCode.getGraphics();

    //生成随机类
    Random random = new Random();
    // 设定背景色
    g.setColor(getRandomColor(200, 250));
    g.fillRect(0, 0, width, height);
    //设定字体
    g.setFont(new Font("Times New Roman", Font.PLAIN, 18));

    // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
    g.setColor(getRandomColor(160, 200));
    for (int i = 0; i < 155; i++) {
      int x = random.nextInt(width);
      int y = random.nextInt(height);
      int xl = random.nextInt(12);
      int yl = random.nextInt(12);
      g.drawLine(x, y, x + xl, y + yl);
    }

    for (int i = 0; i < length; i++) {
      String rand = String.valueOf(chr[random.nextInt(chr.length)]);
      charRandomCode += rand;
      // 将认证码显示到图象中
      g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
      g.drawString(rand, 13 * i + 6, 16);
    }
    g.dispose();
  }

  /**
   * 给定范围获得随机颜色
   *
   * @param fc
   * @param bc
   * @return Color
   */
  private Color getRandomColor(int fc, int bc) {
    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);
  }
}