日期:2014-05-16 浏览次数:20406 次
out.clear(); out = pageContext.pushBody();
import java.io.*; import javax.servlet.http.*; import javax.servlet.*; import java.util.*; import java.awt.*; import java.awt.image.*; import javax.imageio.*; public class vImage extends HttpServlet { public void init(ServletConfig conf) throws ServletException { super.init(conf); } public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { res.setContentType(”image/jpeg”); res.setHeader(”Pragma”, “No-cache”); res.setHeader(”Cache-Control”, “no-cache”); res.setDateHeader(”Expires”, 0); HttpSession session = req.getSession(); // 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); // 设定字体 g.setFont(new Font(”Times New Roman”, Font.PLAIN, 18)); // 画边框 //g.setColor(new Color()); //g.drawRect(0,0,width-1,height-1); // 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 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); } }
vImage /vimage 注:注意元素在web.xml文件里的位置
function reloadImage(url) { document.form名字.pic.src = url; }
<%@ page import = "java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" %> <%@ page import = "java.io.OutputStream" %> <%@ page pageEncoding= "UTF-8" %> <%!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