jsp验证码 javax.imageio.IIOException: Can't create output stream! 问题解决方案

  新建：image.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
	String path = request.getContextPath();
	String basePath = request.getScheme() + "://"
			+ request.getServerName() + ":" + request.getServerPort()
			+ path + "/";
%>
<%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*,com.sun.image.codec.jpeg.JPEGCodec,com.sun.image.codec.jpeg.JPEGImageEncoder" %> 
<%!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);
	}%> 
<%
 	out.clear();//这句针对resin服务器，如果是tomacat可以不要这句 
 	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);
 	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, 24));
 	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(50 + random.nextInt(110), 50 + random
 				.nextInt(110), 20 + random.nextInt(110)));
 		g.drawString(rand, 13 * i + 6, 16);
 	}
 	// 将认证码存入SESSION 
 	session.setAttribute("rand", sRand);
 	g.dispose();
                //javax.imageio.IIOException: Can't create output stream! 问题解决方案


          //ImageIO.write(image, "jpeg", response.getOutputStream()); 改为下面2行 input javax.imageio.IIOException: Can't create output stream! 
                JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(response.getOutputStream());
 	encoder.encode(image); 
 	out = pageContext.pushBody();
 %>

 

  页面引用html
function loadimage() {
	document.getElementById("randImage").src = "image.jsp?" + Math.random();
}
<img alt="code..." name="randImage" id="randImage" src="image.jsp" width="60" height="20" border="1" align="absmiddle" onclick="javascript:loadimage();">

 

评论

2 楼 yangliuwillow 2015-08-20  

javascript

1 楼 alfusen_xiong 2013-03-18  

我也碰到这个问题，按照楼主的方法，确实可行。感谢楼主的分享精神，是我辈学习之楷模！