java隨機(jī)驗(yàn)證碼生成實(shí)現(xiàn)實(shí)例代碼

package cn.songxinqiang.tool.util;

import java.util.Arrays;

public class RandomSecurityCode {
 /**
 * 驗(yàn)證碼難度級(jí)別，Simple只包含數(shù)字，Medium包含數(shù)字和小寫英文，Hard包含數(shù)字和大小寫英文
 */
 public enum SecurityCodeLevel {
 Simple, Medium, Hard
 };

 // 字符集合(除去易混淆的數(shù)字0、數(shù)字1、字母l、字母o、字母O)
 private final char[] CHAR_CODE = { '1', '2', '3', '4', '5', '6',
 '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
 'k', 'm', 'n', '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', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };

 /**
 * 產(chǎn)生默認(rèn)驗(yàn)證碼，4位中等難度<br>
 * 調(diào)用此方法和調(diào)用getSecurityCode(4, SecurityCodeLevel.Medium, false)有一樣的行為
 * 
 * @see #getSecurityCode(int, SecurityCodeLevel, boolean)
 * @return 驗(yàn)證碼
 */
 public char[] getSecurityCode() {
 return getSecurityCode(4, SecurityCodeLevel.Medium, false);
 }

 /**
 * 獲取驗(yàn)證碼，指定長度、難度、是否允許重復(fù)字符
 * 
 * @param length
 *   長度
 * @param level
 *   難度
 * @param isCanRepeat
 *   是否允許重復(fù)字符
 * @return 驗(yàn)證碼
 */
 public char[] getSecurityCode(int length, SecurityCodeLevel level,
 boolean isCanRepeat) {
 // 隨機(jī)抽取len個(gè)字符
 int len = length;
 char[] code;

 // 根據(jù)不同的難度截取字符數(shù)組
 switch (level) {
 case Simple: {
 code = Arrays.copyOfRange(CHAR_CODE, 0, 9);
 break;
 }
 case Medium: {
 code = Arrays.copyOfRange(CHAR_CODE, 0, 33);
 break;
 }
 case Hard: {
 code = Arrays.copyOfRange(CHAR_CODE, 0, CHAR_CODE.length);
 break;
 }
 default: {
 code = Arrays.copyOfRange(CHAR_CODE, 0, CHAR_CODE.length);
 }
 }

 // 字符集合長度
 int n = code.length;

 // 拋出運(yùn)行時(shí)異常
 if (len > n && isCanRepeat == false) {
 throw new RuntimeException(String.format(
  "調(diào)用SecurityCode.getSecurityCode(%1$s,%2$s,%3$s)出現(xiàn)異常，"
  + "當(dāng)isCanRepeat為%3$s時(shí)，傳入?yún)?shù)%1$s不能大于%4$s", len,
  level, isCanRepeat, n));
 }
 // 存放抽取出來的字符
 char[] result = new char[len];
 // 判斷能否出現(xiàn)重復(fù)的字符
 if (isCanRepeat) {
 for (int i = 0; i < result.length; i++) {
 // 索引 0 and n-1
 int r = (int) (Math.random() * n);

 // 將result中的第i個(gè)元素設(shè)置為codes[r]存放的數(shù)值
 result[i] = code[r];
 }
 } else {
 for (int i = 0; i < result.length; i++) {
 // 索引 0 and n-1
 int r = (int) (Math.random() * n);

 // 將result中的第i個(gè)元素設(shè)置為codes[r]存放的數(shù)值
 result[i] = code[r];

 // 必須確保不會(huì)再次抽取到那個(gè)字符，因?yàn)樗谐槿〉淖址仨毑幌嗤? // 因此，這里用數(shù)組中的最后一個(gè)字符改寫codes[r]，并將n減1
 code[r] = code[n - 1];
 n--;
 }
 }
 return result;
 }
}

package cn.songxinqiang.tool.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;

/**
 * 驗(yàn)證碼圖片生成工具類
 * 
 * @since sxq-tool-1.0.2
 * @date 2014年3月11日 上午10:48:02
 * @author 宋信強(qiáng)
 * @mail songxinqiang@vip.qq.com
 */
public class RandomSecurityImage {

 private Random random = new Random();

 private Font font = new Font("Fixedsys", Font.CENTER_BASELINE, 18);

 /**
 * 根據(jù)指定的字符和大小生成隨機(jī)驗(yàn)證碼圖片
 * @param code 需要繪制到圖片上的字符數(shù)組
 * @param width 圖片寬度
 * @param height 圖片高度
 * @param line 干擾線數(shù)量
 * @return 圖片的輸入流
 */
 public ByteArrayInputStream getImage(char[] code, int width,
 int height, int line) {
 // BufferedImage類是具有緩沖區(qū)的Image類,Image類是用于描述圖像信息的類
 BufferedImage image = new BufferedImage(width, height,
 BufferedImage.TYPE_INT_BGR);
 Graphics g = image.getGraphics();
 g.fillRect(0, 0, width, height);
 g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
 g.setColor(getRandColor(110, 133));
 // 繪制干擾線
 for (int i = 0; i < line; i++) {
 drowLine(g, width, height);
 }
 // 繪制隨機(jī)字符
 for (int i = 0; i < code.length; i++) {
 drowChar(g, width / code.length * i, random.nextInt(height / 3)
  + height / 3, code[i]);
 }
 g.dispose();

 return convertImageToStream(image);
 }

 /**
 * 將BufferedImage轉(zhuǎn)換成ByteArrayInputStream
 * 
 * @param image
 *   圖片
 * @return ByteArrayInputStream 流
 */
 private ByteArrayInputStream convertImageToStream(BufferedImage image) {
 ByteArrayInputStream inputStream = null;
 ByteArrayOutputStream bos = new ByteArrayOutputStream();
 try {
 ImageIO.write(image, "JPEG", bos);
 byte[] bts = bos.toByteArray();
 inputStream = new ByteArrayInputStream(bts);
 } catch (IOException e1) {
 }
 return inputStream;
 }

 /*
 * 獲得顏色
 */
 private Color getRandColor(int fc, int bc) {
 if (fc > 255) {
 fc = 255;
 }
 if (bc > 255) {
 bc = 255;
 }
 int r = fc + random.nextInt(bc - fc - 16);
 int g = fc + random.nextInt(bc - fc - 14);
 int b = fc + random.nextInt(bc - fc - 18);
 return new Color(r, g, b);
 }

 /*
 * 繪制字符
 */
 private char drowChar(Graphics g, int x, int y, char code) {
 g.setFont(font);
 g.setColor(getRandColor(10, 200));
 g.translate(random.nextInt(3), random.nextInt(3));
 g.drawString(code + "", x, y);
 return code;
 }

 /*
 * 繪制干擾線
 */
 private void drowLine(Graphics g, int width, int height) {
 int x = random.nextInt(width);
 int y = random.nextInt(height);
 int xl = random.nextInt(width / 2);
 int yl = random.nextInt(height / 2);
 g.drawLine(x, y, x + xl, y + yl);
 }
}

char[] charCode = randomCode.getSecurityCode(6, SecurityCodeLevel.Hard,true);
(提前聲明了的ByteArrayInputStream) inputStream = randomImage.getImage(charCode, 130, 34, 20);

<result name="stream" type="stream">
 <param name="contentType">image/jpeg</param>
 <param name="inputName">inputStream</param>
 <param name="bufferSize">2048</param>
</result>