验证码工具类

来源：互联网发布：淘宝网电子商务类型编辑：程序博客网时间：2024/05/20 00:49
花了一个多小时，写了一个获取验证码的工具类，具体代码如下
主要功能：
获取一张随机图片，显示验证码
以字符串形式保存本次随机图片上的字符
效果图：
这里写图片描述
代码如下：
package com.huaxin.utils;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.Image;import java.awt.image.BufferedImage;import java.util.Random;public class ValidateCodeUtil {    private ValidateCodeUtil() {    }    private static Random r = new Random();    private static final double factor = 0.75;// 计算字体大小    private static StringBuilder validateCode = new StringBuilder();// 只保存一次当前验证码    private static final char NUM[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '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', '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' };    public static Image getValidateCodeImage() {        return getValidateCodeImage(100, 50);    }    public static Image getValidateCodeImage(int width, int height) {        return getValidateCodeImage(width, height, 4);    }    public static Image getValidateCodeImage(int width, int height, int length) {        return getValidateCodeImage(width, height, length, 10, 50);    }    public static Image getValidateCodeImage(int width, int height, int length, int randomLineCount,            int randomPointCount) {        // 构建一副图片        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);        // 获取设置图片内容的画笔        Graphics g = image.getGraphics();        // 设置背景        setBackGround(g, width, height);        // 设置边框        setBorder(g);        // 添加干扰线        drawRandomLine(g, width, height, randomLineCount);        // 添加干扰点        drawRandomPoint(g, width, height, randomPointCount);        // 写随机数        drawRandomNum((Graphics2D) g, width, height, length);        g.dispose();        return image;    }    public static String getValidateCode() {        return validateCode.toString();    }    private static void drawRandomNum(Graphics2D g, int width, int height, int length) {        validateCode.delete(0, validateCode.length());// 下次获取验证码时必须先清空        int x = 3;        int size = (int) (height * factor);        int y = height / 2 + size / 2 - 5;        g.setFont(new Font("宋体", 0, size));        // 文字旋转度数        int degree = 0;        for (int i = 0; i < length; i++) {            g.setColor(getRandomColor(0, 255));            degree = r.nextInt(60) - 30;// 设置旋转角度            g.rotate((degree * Math.PI) / 180, x, y);// 进行文字旋转            int index = r.nextInt(NUM.length);// 保存本次数组角标            g.drawString(String.valueOf(NUM[index]), x, y);            g.rotate(-(degree * Math.PI) / 180, x, y);// 还原旋转角度            x = x + width / length;            // 记录随机验证码            validateCode.append(NUM[index]);        }    }    private static void drawRandomPoint(Graphics g, int width, int height, int randomPointCount) {        int x = 0;        int y = 0;        for (int i = 0; i < randomPointCount; i++) {            g.setColor(getRandomColor(0, 255));            x = r.nextInt(width);            y = r.nextInt(height);            g.drawLine(x, y, x, y);        }    }    private static void drawRandomLine(Graphics g, int width, int height, int randomLineCount) {        for (int i = 0; i < randomLineCount; i++) {            g.setColor(getRandomColor(0, 255));            g.drawLine(r.nextInt(width), r.nextInt(height), r.nextInt(width), r.nextInt(height));        }    }    private static void setBorder(Graphics g) {    }    private static void setBackGround(Graphics g, int width, int height) {        g.setColor(getRandomColor(220, 255));        g.fillRect(0, 0, width, height);    }    // 获取一个随机颜色    private static Color getRandomColor(int low, int high) {        int sub = high - low + 1;        return new Color(low + r.nextInt(sub), low + r.nextInt(sub), low + r.nextInt(sub));    }}
0 0