登录注册彩色验证码刷新

package com.cqjd.util; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; import java.util.Random; import javax.imageio.ImageIO; public class RndImage { //定义随机字符串 private static char mapTable[] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h','i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u','v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7','8', '9' }; /*获取随机字符串*/ public static String random() { String str = ""; // 5代表5位验证码，如果要生成更多位的认证码，则加大数值ֵ for (int i = 0; i < 5; ++i) { str += mapTable[(int) (mapTable.length * Math.random())]; } return str; } /*获取随机颜色对象*/ public static Color getRandomColor() { Color col = null; Random rnd = new Random(); col = new Color(rnd.nextInt(180), rnd.nextInt(180), rnd.nextInt(180)); return col; } /* 将随机字符串转换成图像到写入流： * num:随机字符串 * out：输出流 * width：图片宽度 * height：图片高度 */ public static void imageOut(String num, OutputStream out, int width, int height) throws IOException { // 定义缓冲区图像 rndImg BufferedImage rndImg = null; rndImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); //定义二维图像画笔对象 g Graphics2D g = (Graphics2D) rndImg.getGraphics(); //设置矩形填充颜色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); //设置显示字体及字体类型与大小 Font mFont = new Font("Tahoma", Font.BOLD, height * 3 / 4); g.setFont(mFont); g.setColor(Color.BLACK); //设置默认字体颜色 String str1[] = new String[5]; //定义存放5个单元的的字符串数组 for (int i = 0; i < str1.length; i++) { // 绘制验证码字符 str1[i] = "" + num.charAt(i); g.setColor(getRandomColor()); g.drawString(str1[i], 15 * i + 5, height * 4 / 5); } // 设置干扰线 g.setColor(Color.LIGHT_GRAY); Random random = new Random(); for (int i = 0; i < 40; i++) { int x1 = random.nextInt(width); int y1 = random.nextInt(height); int x2 = random.nextInt(10); int y2 = random.nextInt(10); // 在点(x1, y1)与点(x1 + x2, y1 + y2)֮之间画一条直线 g.drawLine(x1, y1, x1 + x2, y1 + y2); } // 绘制外框线 g.drawRect(0, 0, width - 1, height - 1); // 释放画笔 g.dispose(); // 将一个图像写入OutPutStream //rndImg-要写入的图片缓冲区对象："jpg"-图像格式 // out-将在其中写入数据的 OutputStream // 将内存图像写出到输出流 ImageIO.write(rndImg, "jpg", out); } }