验证码（二）

image.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%>
<%@page import="java.io.OutputStream"%>

<%!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);
	}%>
<%
	try {
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		int width = 60, height = 20;
		BufferedImage image = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		OutputStream os = response.getOutputStream();
		Graphics g = image.getGraphics();
		Random random = new Random();
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);

		g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
		g.setColor(getRandColor(160, 200));
		for (int i = 0; i < 155; 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);
		}
		String sRand = "";
		for (int i = 0; i < 4; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand += rand;
			g.setColor(new Color(20 + random.nextInt(110), 20 + random
					.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(rand, 13 * i + 6, 16);
		}
		session.setAttribute("rand", sRand);	// 验证码 加入Session
		g.dispose();

		ImageIO.write(image, "JPEG", os);
		os.flush();
		os.close();
		os = null;
		//response.flushBuffer();
		out.clear();
		out = pageContext.pushBody();
	} catch (IllegalStateException e) {
		System.out.println(e.getMessage());
		e.printStackTrace();
	}
%>

login.jsp

<td class="LoginLabel">							验证码:					
<td>
	<h:inputText id="vcode" styleClass="inputValidate"
		tabindex="3" required="true" size="8" style="ime-mode:disabled" requiredMessage="*" validatorMessage="验证码不能为空">
	</h:inputText>
	<h:graphicImage id="rand" url="image.jsp" alt="验证码"
		styleClass="validateImg" />
</td>
<td>
	<span style="color: #ffffff; font-size: 12px; 
         cursor: pointer;"	onclick="document.getElementById('login:rand').src='image.jsp?'+Math.random();">看不清楚,<br />
		更换一张!</span>
</td>