我们平时开发时经常会遇到需要图片验证码，基础的验证码包括了数字、字母、甚至可能有汉字。下面我给出一个简单的工具类。

package com..ankang.tony.util;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics2D;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.util.Date;

import java.util.Random;

import javax.imageio.ImageIO;

/**

 * 验证码生成器

 */

public class ValidateCode {

    // 图片的宽度。

    private int width = 160;

    // 图片的高度。

    private int height = 40;

    // 验证码字符个数

    private int codeCount = 5;

    // 验证码干扰线数

    private int lineCount = 150;

    // 验证码

    private static String code = null;

    // 验证码图片Buffer

    private BufferedImage buffImg = null;

    private char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R',

            'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };

    public ValidateCode() {

        this.createCode();

    }

    /**

     *

     * @param width

     *            图片宽

     * @param height

     *            图片高

     */

    public ValidateCode(int width, int height) {

        this.width = width;

        this.height = height;

        this.createCode();

    }

    /**

     *

     * @param width

     *            图片宽

     * @param height

     *            图片高

     * @param codeCount

     *            字符个数

     * @param lineCount

     *            干扰线条数

     */

    public ValidateCode(int width, int height, int codeCount, int lineCount) {

        this.width = width;

        this.height = height;

        this.codeCount = codeCount;

        this.lineCount = lineCount;

        this.createCode();

    }

    public void createCode() {

        int x = 0, fontHeight = 0, codeY = 0;

        int red = 0, green = 0, blue = 0;

        x = width / (codeCount + 1);// 每个字符的宽度

        fontHeight = height - 2;// 字体的高度

        codeY = height - 3;

        // 图像buffer

        buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        Graphics2D g = buffImg.createGraphics();

        // 生成随机数

        Random random = new Random();

        // 将图像填充为白色

        g.setColor(Color.WHITE);

        g.fillRect(0, 0, width, height);

        // 创建字体

        ImgFontByte imgFont = new ImgFontByte();

        Font font = imgFont.getFont(fontHeight);

        g.setFont(font);

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

            int xs = random.nextInt(width);

            int ys = random.nextInt(height);

            int xe = xs + random.nextInt(width / 8);

            int ye = ys + random.nextInt(height / 8);

            red = random.nextInt(255);

            green = random.nextInt(255);

            blue = random.nextInt(255);

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

            g.drawLine(xs, ys, xe, ye);

        }

        // randomCode记录随机产生的验证码

        StringBuffer randomCode = new StringBuffer();

        // 随机产生codeCount个字符的验证码。

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

            String strRand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);

            // 产生随机的颜色值，让输出的每个字符的颜色值都将不同。

            red = random.nextInt(255);

            green = random.nextInt(255);

            blue = random.nextInt(255);

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

            g.drawString(strRand, (i + 1) * x, codeY);

            // 将产生的四个随机数组合在一起。

            randomCode.append(strRand);

        }

        // 将四位数字的验证码保存到Session中。

        code = randomCode.toString();

    }

    public void write(String path,String fileName) throws IOException {

        File folder = new File(path);

        if(!folder.exists()){

            folder.mkdirs();

        }

        OutputStream sos = new FileOutputStream(path+fileName);

        this.write(sos);

    }

    public void write(OutputStream sos) throws IOException {

        ImageIO.write(buffImg, "png", sos);

        sos.close();

    }

    public BufferedImage getBuffImg() {

        return buffImg;

    }

    public String getCode() {

        return code;

    }

    public static void main(String[] args) {

        ValidateCode vCode = new ValidateCode(120,40,5,50);

        try {

            String path="D:\\report\\image\\code\\";

            System.out.println(vCode.getCode()+" >"+path);

            vCode.write(path,new Date().getTime()+".png");

        } catch (IOException e) {

            e.printStackTrace();

        }

     }

}

下面这个类主要是用作字体的设置，大家也可以直接拿过来用。

package com.ankang.tony.util;

import java.awt.Font;

import java.io.ByteArrayInputStream;

public class ImgFontByte {

     public Font getFont(int fontHeight){

            try {

                Font baseFont = Font.createFont(Font.ITALIC, new ByteArrayInputStream(hex2byte(getFontByteStr())));

                return baseFont.deriveFont(Font.PLAIN, fontHeight);

            } catch (Exception e) {

                return new Font("Consola",Font.PLAIN, fontHeight);

            }

        }  

        private  byte[] hex2byte(String str) {

            if (str == null)

                return null;

            str = str.trim();

            int len = str.length();

            if (len == 0 || len % 2 == 1)

                return null;

            byte[] b = new byte[len / 2];

            try {

                for (int i = 0; i < str.length(); i += 2) {

                    b[i/2] = (byte) Integer.decode("0x" + str.substring(i, i + 2)).intValue();

                }

                return b;

            } catch (Exception e) {

                return null;

            }

        } 

     /**

      * ttf字体文件的十六进制字符串

      * @return

      */

     private String getFontByteStr(){

         return null;

     }

}