验证码

jsp:

<table border="0" align="center" width="80%" cellpadding="5" cellspacing="0">
                    <tr>
                    	<td width="50" height="30">用户名：</td>
                        <td><input type="text" size="20" name="username" value="${username}"/></td>
                    </tr>
                    <tr>
                    	<td height="30">密&nbsp;&nbsp;码：</td>
                        <td><input type="password" size="20"  name="password" value=""/>
                        
                        </td>
                    </tr>
                     <tr>
                    	<td height="30">验证码：</td>
                        <td><input type="text" size="8"  name="yanzhengCode" />
                        	<img style="cursor:pointer;" src="rand.action" onclick="changeValidateCode(this)" />
                        </td>
                    </tr> 
                    </table>

 function changeValidateCode(obj) {
        var currentTime= new Date().getTime();
        obj.src = "rand.action?d=" + currentTime;
    }

 

 

action:

package com.xy.action;

import java.util.HashMap;
import java.util.Map;
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.Map;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.interceptor.ServletRequestAware;

import com.xy.dao.ILoginDao;
import com.xy.entity.UserBean;

public class LoginAction implements  ServletRequestAware{

	private HttpServletRequest request;
	public HttpServletRequest getRequest() {
		return request;
	}

	public void setServletRequest(HttpServletRequest request) {
		this.request = request;
	}
	private ILoginDao loginDao;
	private String username;
	private String password;
	public String login(){
		String code = request.getParameter("yanzhengCode");
		System.out.println(code);
		String rand = (String)request.getSession().getAttribute("rand");
		
		
		Map<String, Object> loginMap = new HashMap<String, Object>();
		loginMap.put("username", username);
		loginMap.put("pwd", password);
		UserBean user =	loginDao.toLogin(loginMap);
		request.getSession().removeAttribute("LoginError");
		if(user != null){
			if(code==null||!code.equals(rand)){
				request.getSession().setAttribute("codeError", "验证码输入错误！");
				return "codeError";
			}else {
				request.getSession().setAttribute("qtUser", user);
				return "success";
			}
		}else {
			request.getSession().setAttribute("LoginError", "您的用户名或密码错误 ！");
			return "loginError";
		}
	}

	
	public String LoginOut(){
		request.getSession().invalidate();
		return "success";
	}
	
	
	private ByteArrayInputStream inputStream; 
	public String getYanzhengCode() throws Exception{
		// 在内存中创建图象
				int width = 60, height = 20;

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

				// 获取图形上下文
				Graphics g = image.getGraphics();

				// 生成随机类
				Random random = new Random();

				// 设定背景色
				g.setColor(getRandColor(200, 250));
				g.fillRect(0, 0, width, height);//fillRect（x,y,w,h）函数的作用是：填充一个矩形区域，x、y为起始坐标（即左上角坐标）,
				//后面两个参数分别为：w、h,是矩形区域的宽和高,

				// 设定字体
				g.setFont(new Font("Times New Roman", Font.PLAIN, 18));//第一个参数字体，第二个参数：STYLE_PLAIN——普通l ，第三个参数：字体大小

				// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
				g.setColor(getRandColor(160, 200));
				for (int i = 0; i < 200; i++) {
					int x = random.nextInt(width);
					int y = random.nextInt(height);
					int xl = random.nextInt(12);
					int yl = random.nextInt(12);
					g.drawLine(x, y, x + xl, y + yl);
				}

				// 取随机产生的认证码(6位数字)
				String sRand = "";
				for (int i = 0; i < 4; i++) {
					String rand = String.valueOf(random.nextInt(10));
					sRand += rand;
					// 将认证码显示到图象中
					g.setColor(new Color(20 + random.nextInt(110), 20 + random
							.nextInt(110), 20 + random.nextInt(110)));
					// 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
					g.drawString(rand, 13 * i + 6, 16);
				}

				// 将认证码存入SESSION
				request.getSession().setAttribute("rand", sRand);

				// 图象生效
				g.dispose();
				ByteArrayOutputStream output = new ByteArrayOutputStream();
				ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);
				ImageIO.write(image, "JPEG", imageOut);
				imageOut.close();
				ByteArrayInputStream input = new ByteArrayInputStream(output
						.toByteArray());
				this.setInputStream(input);
				return "success";
	}
	
	/*
	 * 给定范围获得随机颜色
	 */
	private Color getRandColor(int fc, int bc) {
		Random random = new Random();
		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);
	}
	
	//get set

	public void setUsername(String username) {
		this.username = username;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public ILoginDao getLoginDao() {
		return loginDao;
	}

	public void setLoginDao(ILoginDao loginDao) {
		this.loginDao = loginDao;
	}

	public ByteArrayInputStream getInputStream() {
		return inputStream;
	}

	public void setInputStream(ByteArrayInputStream inputStream) {
		this.inputStream = inputStream;
	}
	
	
}

 

 

xlm:

 

		<action name="rand" class="com.xy.action.LoginAction" method="getYanzhengCode">
			<result type="stream">
				<param name="contentType">image/jpeg</param>
				<param name="inputName">inputStream</param>
			</result>
		</action>