Java 生成验证码

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java生成验证码

有很多种方式，在网上也有很多代码，但是那些生成的效果，感觉都不是特别好，所以我在他们的基础上改良了一些。

但能还可以用jmagick ,生成很多很炫的验证码。过两天研究下。先把最近改的这个发布下供朋友们参。

 

可以先看看样例。最近在做这个网站。大家有兴趣可以叫交流。约会360 网址:  www.yuehui360.com 

验证码效果可以在

约会360注册页面 http://www.yuehui360.com/register.htm 查看效果

 

图片效果：

 

 

 

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代码如下：

package com.idate.util; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; /** * @author lqinglong@yahoo.cn * 约会360 www.yuehui360.com */ public class CodeHelper { private static final CodeHelper generator = new CodeHelper(); private final String ATTRIBUTE_NAME = "code"; //图片的宽度 private final int WIDTH = 35; //图片的高度 private final int HEIGHT = 55; //字符串长度 private final int CODE_LENGTH = 4; //随机字符串范围 private final String RAND_RANGE = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890" ; private final char[] CHARS = RAND_RANGE.toCharArray(); private Random random = new Random(); private CodeHelper(){ // } public static CodeHelper getInstance(){ return generator; } /** * 生成随机字符串 * @return 随机字符串 */ private String getRandString(){ StringBuilder sb = new StringBuilder(); for (int i = 0; i < CODE_LENGTH; i++) sb.append(CHARS[random.nextInt(CHARS.length)]); return sb.toString(); } /** * 生成随机颜色 * @param ll 产生颜色值下限(lower limit) * @param ul 产生颜色值上限(upper limit) * @return 生成的随机颜色对象 */ private Color getRandColor(int ll, int ul){ if (ll > 255) ll = 255; if (ll < 1) ll = 1; if (ul > 255) ul = 255; if (ul < 1) ul = 1; if (ul == ll) ul = ll + 1; int r = random.nextInt(ul - ll) + ll; int g = random.nextInt(ul - ll) + ll; int b = random.nextInt(ul - ll) + ll; Color color = new Color(r,g,b); return color; } /** * 生成指定字符串的图像数据 * @param verifyCode 即将被打印的随机字符串 * @return 生成的图像数据 * */ private BufferedImage getImage(String verifyCode){ BufferedImage image = new BufferedImage(WIDTH * CODE_LENGTH, HEIGHT, BufferedImage.TYPE_INT_RGB); //获取图形上下文 Graphics graphics = image.getGraphics(); //设置背景色 graphics.setColor(new Color(255,255,255)); //graphics.setColor(this.getRandColor(0, 50)); //填充背景色 graphics.fillRect(0, 0, WIDTH * 4, HEIGHT); //设置随机干扰线条颜色 graphics.setColor(getRandColor(50,100)); //graphics.translate(x, y) //产生50条干扰线条 for (int i=0; i<10; i++){ int x1 = random.nextInt(WIDTH * CODE_LENGTH - 4) + 2; int y1 = random.nextInt(HEIGHT - 4) + 2; int x2 = random.nextInt(WIDTH * CODE_LENGTH - 2 - x1) + x1; int y2 = y1; graphics.drawLine(x1, y1, x2, y2); } //设置字体 Font font = new Font("Times New Roman",Font.PLAIN,25); graphics.setFont(font); //画字符串 for (int i=0; i<this.CODE_LENGTH; i++){ int r = random.nextInt(4); System.out.print("r==="+r+" "); int size = 40+random.nextInt(10) ; font = font.deriveFont(r, size); graphics.setFont(font); String temp = verifyCode.substring(i, i+1); graphics.setColor(getRandColor(1,200)); int x = (10+random.nextInt(20))+25*i; int y = random.nextInt(10)+35; System.out.println("i="+i+" x=="+x+" y="+y); graphics.drawString(temp,x, y); } //图像生效 graphics.dispose(); return image; } /** * 将验证码的图像输出 * @param request 用户的请求对象 * @param response 用户的响应对象 * */ public void printImage(HttpServletRequest request, HttpServletResponse response){ //将ContentType设为"image/jpeg"，让浏览器识别图像格式。 response.setContentType("image/jpeg"); //设置页面不缓存 response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 2000); //获得随机验证码 String verifyCode = this.getRandString(); String str = "ssss"; for(int i=0; i<10; i++) str = str + str; //获得验证码的图像数据 BufferedImage bi = this.getImage(verifyCode); //把验证码存入session request.getSession().setAttribute(ATTRIBUTE_NAME, verifyCode); try{ //获得Servlet输出流 ServletOutputStream outStream = response.getOutputStream(); //创建可用来将图像数据编码为JPEG数据流的编码器 JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(outStream); //将图像数据进行编码 encoder.encode(bi); //强行将缓冲区的内容输入到页面 outStream.flush(); //关闭输出流 outStream.close(); }catch(IOException ex){ ex.printStackTrace(); } } /** * 检查输入的验证码是否正确，若用户输入的验证码与生成的验证码相符则返回true，否则返回false。 * @param request 用户的请求对象 * @return 验证结果 * */ public boolean check(HttpServletRequest request){ if (((String)request.getParameter(ATTRIBUTE_NAME)) .equalsIgnoreCase((String)request.getSession().getAttribute(ATTRIBUTE_NAME))){ request.getSession().removeAttribute(ATTRIBUTE_NAME); return true; } return false; } public static void main(String [] args){ CodeHelper code = CodeHelper.getInstance(); code.getImage("123y"); } }