验证码生成

vcode.jsp

<%@page import="com.yc.res.util.VerifyCodeUtils"%>//包名

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

<%

// 生成验证码

String vcode = VerifyCodeUtils.outputImage(100, 40, 4, response);

// 讲验证码保存到会话中

session.setAttribute("vcode", vcode);

// 解决jsp生成验证码报错

pageContext.getOut().clear();

%>

---

VerifyCodeUtils

package com.yc.res.util;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.RenderingHints;

import java.awt.geom.AffineTransform;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.util.Arrays;

import java.util.Random;

import javax.imageio.ImageIO;

import javax.servlet.http.HttpServletResponse;

/**

* 验证码生成工具

*/

public class VerifyCodeUtils {

public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";

private static Random random = new Random();

public static String generateVerifyCode(int verifySize) {

return generateVerifyCode(verifySize, VERIFY_CODES);

}

public static String generateVerifyCode(int verifySize, String sources) {

if (sources == null || sources.length() == 0) {

sources = VERIFY_CODES;

}

int codesLen = sources.length();

Random rand = new Random(System.currentTimeMillis());

StringBuilder verifyCode = new StringBuilder(verifySize);

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

verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));

}

return verifyCode.toString();

}

public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {

String verifyCode = generateVerifyCode(verifySize);

outputImage(w, h, outputFile, verifyCode);

return verifyCode;

}

public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException {

String verifyCode = generateVerifyCode(verifySize);

outputImage(w, h, os, verifyCode);

return verifyCode;

}

public static void outputImage(int w, int h, File outputFile, String code) throws IOException {

if (outputFile == null) {

return;

}

File dir = outputFile.getParentFile();

if (!dir.exists()) {

dir.mkdirs();

}

try {

outputFile.createNewFile();

FileOutputStream fos = new FileOutputStream(outputFile);

outputImage(w, h, fos, code);

fos.close();

} catch (IOException e) {

throw e;

}

}

public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {

int verifySize = code.length();

BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);

Random rand = new Random();

Graphics2D g2 = image.createGraphics();

g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

Color[] colors = new Color[5];

Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN, Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA,

Color.ORANGE, Color.PINK, Color.YELLOW };

float[] fractions = new float[colors.length];

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

colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];

fractions[i] = rand.nextFloat();

}

Arrays.sort(fractions);

g2.setColor(Color.GRAY);

g2.fillRect(0, 0, w, h);

Color c = getRandColor(200, 250);

g2.setColor(c);

g2.fillRect(0, 2, w, h - 4);

Random random = new Random();

g2.setColor(getRandColor(160, 200));

for (int i = 0; i < 20; i++) {

int x = random.nextInt(w - 1);

int y = random.nextInt(h - 1);

int xl = random.nextInt(6) + 1;

int yl = random.nextInt(12) + 1;

g2.drawLine(x, y, x + xl + 40, y + yl + 20);

}

float yawpRate = 0.05f;

int area = (int) (yawpRate * w * h);

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

int x = random.nextInt(w);

int y = random.nextInt(h);

int rgb = getRandomIntColor();

image.setRGB(x, y, rgb);

}

shear(g2, w, h, c);

g2.setColor(getRandColor(100, 160));

int fontSize = h - 4;

Font font = new Font("Algerian", Font.ITALIC, fontSize);

g2.setFont(font);

char[] chars = code.toCharArray();

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

AffineTransform affine = new AffineTransform();

affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1),

(w / verifySize) * i + fontSize / 2, h / 2);

g2.setTransform(affine);

g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);

}

g2.dispose();

ImageIO.write(image, "jpg", os);

}

private static Color getRandColor(int fc, int bc) {

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);

}

private static int getRandomIntColor() {

int[] rgb = getRandomRgb();

int color = 0;

for (int c : rgb) {

color = color << 8;

color = color | c;

}

return color;

}

private static int[] getRandomRgb() {

int[] rgb = new int[3];

for (int i = 0; i < 3; i++) {

rgb[i] = random.nextInt(255);

}

return rgb;

}

private static void shear(Graphics g, int w1, int h1, Color color) {

shearX(g, w1, h1, color);

shearY(g, w1, h1, color);

}

private static void shearX(Graphics g, int w1, int h1, Color color) {

int period = random.nextInt(2);

boolean borderGap = true;

int frames = 1;

int phase = random.nextInt(2);

for (int i = 0; i < h1; i++) {

double d = (double) (period >> 1)

* Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);

g.copyArea(0, i, w1, 1, (int) d, 0);

if (borderGap) {

g.setColor(color);

g.drawLine((int) d, i, 0, i);

g.drawLine((int) d + w1, i, w1, i);

}

}

}

private static void shearY(Graphics g, int w1, int h1, Color color) {

int period = random.nextInt(40) + 10;

boolean borderGap = true;

int frames = 20;

int phase = 7;

for (int i = 0; i < w1; i++) {

double d = (double) (period >> 1)

* Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);

g.copyArea(i, 0, 1, h1, 0, (int) d);

if (borderGap) {

g.setColor(color);

g.drawLine(i, (int) d, i, 0);

g.drawLine(i, (int) d + h1, i, h1);

}

}

}

public static void main(String[] args) throws IOException {

// 定义图片目录

File dir = new File("d:/verifies");

// 定义图片大小

int w = 200, h = 80;

// 生成 50 个验证码图片

for (int i = 0; i < 50; i++) {

// 随机生成验证码

String verifyCode = generateVerifyCode(4);

// 生成图片文件

File file = new File(dir, verifyCode + ".jpg");

// 输出图片

outputImage(w, h, file, verifyCode);

}

}

/**

* 生成验证码图片输出成图片，返回验证码字符串

* @param width

* @param height

* @param response

* @return

* @throws IOException

*/

public static String outputImage(int width, int height, int length, HttpServletResponse response)

throws IOException {

// 随机生成验证码

String verifyCode = VerifyCodeUtils.generateVerifyCode(length);

// 图形写给浏览器

response.setContentType("image/jpeg");

// 发头控制浏览器不要缓存

response.setDateHeader("expries", -1);

response.setHeader("Cache-Control", "no-cache");

response.setHeader("Pragma", "no-cache");

// 获取响应输出流

OutputStream out = response.getOutputStream();

// 输出图片

outputImage(width, height, out, verifyCode);

return verifyCode;

}

/**

* 输出宽度200、高度80、长度4位的验证码输出到页面，返回验证码字符串

* @param response

* @return

* @throws IOException

*/

public static String outputImage(HttpServletResponse response) throws IOException {

return outputImage(200, 80, 4, response);

}

}