java生成验证码工具类

最新推荐文章于 2025-05-13 15:54:58 发布

nikolas_511

最新推荐文章于 2025-05-13 15:54:58 发布

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分类专栏： java工具类文章标签： java 验证码 java验证码验证码生成生成验证码

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生成后返回验证码字符

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * 生成验证码工具类
 * @author nikolas511
 *
 */
public class VerificationUtils{
	
	private static int WIDTH=100;//图片宽
	private static int HEIGHT=40;//图片长
	public static String getVerification(HttpServletRequest request, HttpServletResponse response) throws IOException{
		//构造一幅图片,并得到图行
		BufferedImage image = new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);
		 Graphics g = image.getGraphics();
		//设置图片的背景,并设置图片的边框
		setBackGround(g);
		
		//增加线条干扰
		setLine(g);
		
		//画出图片中的文字
		String text = setText((Graphics2D)g);
		
		//控制浏览器不要缓存,实际测试中浏览器不缓存
		response.addDateHeader("expries", -1);
		response.setHeader("Cache-Control", "no-cache");
		response.setHeader("Pragma","no-cache");
		//将图片用输出流输出到浏览器中
		ImageIO.write(image, "jpg", response.getOutputStream());
		
		return text;
	}
	private static String setText(Graphics2D g) {
		int x=6,y=32;
		String s ="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
		Color[] color ={Color.BLACK,Color.RED,Color.DARK_GRAY,Color.MAGENTA,Color.ORANGE,
				Color.YELLOW,Color.CYAN,Color.BLUE,Color.ORANGE,Color.GREEN,Color.PINK,
				Color.GRAY};
		String text = "";
		for(int i=0;i<4;i++){
			int num = new Random().nextInt(color.length);
			String ch =s.charAt(new Random().nextInt(s.length()))+"";
			text =text+ch;
			double degree = (new Random().nextInt(30))*Math.PI/180;
			if(!new Random().nextBoolean())degree=-degree;
			Color c = color[num];
			g.setColor(c);
			g.setFont(new Font(ch,Font.BOLD,30));
			g.rotate(degree,x,y);
			g.drawString(ch,x,y);
			g.rotate(-degree,x,y);
			x+=25;//此处设置字符间距
		}
		return text;
	}
	private static void setLine(Graphics g) {
		Color[] color ={Color.YELLOW,Color.CYAN,Color.BLUE,Color.ORANGE,Color.GREEN,Color.PINK};
		for(int i=0; i<=10; i++){
			int num = new Random().nextInt(color.length);
			Color c = color[num];
			g.setColor(c);
			int x1 = new Random().nextInt(150);
			int y1 = new Random().nextInt(40);
			
			int x2 = new Random().nextInt(150);
			int y2 = new Random().nextInt(40);		
			g.drawLine(x1, y1, x2, y2);
		}
	}
	private static void setBackGround(Graphics g) {
		g.setColor(Color.LIGHT_GRAY);
		g.fillRect(0,0, WIDTH, HEIGHT);
		
		g.setColor(Color.BLACK);
		g.drawRect(1, 1, WIDTH-2, HEIGHT-2);
	}

}

此处测试以servlet实例

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.pjj.utils.VerificationUtils;


@WebServlet("/VerificationServlet")
public class VerificationServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String text = VerificationUtils.getVerification(request, response);
		request.getSession().setAttribute("text", text);
		System.out.println(text);
	}

	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		PrintWriter pw = response.getWriter();
		String checknum = request.getParameter("checknum");
		String text = (String) request.getSession().getAttribute("text");
		if(text.equalsIgnoreCase(checknum)){
			pw.write("images/MsgSent.gif");
		}else{
			pw.write("images/MsgError.gif");
		}
		pw.flush();
		pw.close();
	}
}

下面为jsp页面,当输入4个字符后发送ajax请求,此处需要导入jquery的js文件

图片例子

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="js/jquery-1.8.2.min.js"></script>
</head>
<body>
	<table>
		<tr>
			<td>输入验证码:<input id="checknum" size="3" type="text" height="40" maxlength="4"
				name="checknum" onkeyup="check()" /></td>
			<td><span id="res"></span> </td>
			<td><img id="image"  onclick="changeImage(this)"
				src="${pageContext.request.contextPath}/VerificationServlet"></td>
		</tr>
	</table>
	<script type="text/javascript">
		function changeImage(img) {
			img.src = img.src + "?" + new Date().getTime();
			$("#res").html("");
			$("#checknum").val("");
		}
		//去掉两边的空格
		function trim(str){
			str = str.replace(/^\s*/,"");
			str = str.replace(/\s*$/,"");
			return str;
		}
	</script>
	<script type="text/javascript">
		function check(){
			var $checknum = $("#checknum");
			var $str = trim($checknum.val());
			if($str.length==4){
				$.ajax({
					type:"POST",
					url:"VerificationServlet?time=" + new Date().getTime(),
					data:{"checknum":$str},
					success:function(backData){
						var $res = $("#res").html("");
						$("<img src='"+backData+"' style='width:14px;height:14px' />").appendTo($res);
					}
				});
			}else{
				$("#res").html("");
			}
		}
	</script>
</body>
</html>

以上源码及其资料图片下载链接：http://pan.baidu.com/s/1bURheu 密码：5evt