如何使用java2D绘制验证码 用java2D绘制像注册163邮箱一样的验证码,该如何实现? 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 网上搜 很多的,这个以前写的import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.ByteArrayOutputStream;import java.io.IOException;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * 随机生成四位验证码,并输出图像 * @author Declan * */@SuppressWarnings("serial")public class CodeServlet extends HttpServlet { private static final int WIDTH = 60; private static final int HEIGHT = 20; public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("image/jpeg"); // 防止浏览器缓冲 response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); HttpSession session = request.getSession(); BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB); Graphics g = image.getGraphics(); char[] rands = getCode(); drawBackground(g); drawRands(g,rands); g.dispose(); // 使用JPEGImageEncoder // ServletOutputStream out = response.getOutputStream();// JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);// encoder.encode(image);// out.flush(); // 使用ImageIO ServletOutputStream out = response.getOutputStream(); ByteArrayOutputStream bos = new ByteArrayOutputStream(); ImageIO.write(image, "JPEG", bos); byte[] buf = bos.toByteArray(); response.setContentLength(buf.length); out.write(buf); //bos.writeTo(sos); bos.close(); out.close(); session.setAttribute("check", new String(rands)); } /** * 产生四位随机数 * @return */ private char[] getCode(){ String chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; char[] rands = new char[4]; for(int i=0;i<rands.length;i++){ int rand = (int)(Math.random()*chars.length()); rands[i] = chars.charAt(rand); } return rands; } /** * 绘制背景 * @param g */ private void drawBackground(Graphics g){ g.setColor(new Color(0xDCDCDC)); g.fillRect(0, 0, WIDTH, HEIGHT); for(int i=0;i<60;i++){ int x = (int)(Math.random()*WIDTH); int y = (int)(Math.random()*WIDTH); int red = (int)(Math.random()*WIDTH); int green = (int)(Math.random()*WIDTH); int blue = (int)(Math.random()*WIDTH); g.setColor(new Color(red,green,blue)); g.drawOval(x, y, 1, 0); } } /** * 绘制验证码 * @param g * @param rands */ private void drawRands(Graphics g,char[] rands){ g.setColor(Color.black); g.setFont(new Font("黑体",Font.ITALIC|Font.BOLD,18)); g.drawString(""+rands[0], 1, 17); g.drawString(""+rands[1], 16, 15); g.drawString(""+rands[2], 31, 18); g.drawString(""+rands[3], 46, 16); } } 再请问一下在JSP页面中如何调用了? eclipse启动不了 使用Ext.tree.TreeLoader,服务器返回json内容格式是什么? 新手!!jsp读取文本??? 刚开始接触java,想做web开发,大家说该学些什么东西? tomcat究竟如何配置sql server的驱动啊 java.net.URL抓取中文网页的问题 不能创建Bean这是为什么?贴出代码!!!(高分求救) jsp连ORACLE的问题 jsp运行环境配置问题 Servlet 出错了????for input number 大家平时都是怎么调试javascript代码的呀 JSP 中表单提交问题
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
* 随机生成四位验证码,并输出图像
* @author Declan
*
*/
@SuppressWarnings("serial")
public class CodeServlet extends HttpServlet {
private static final int WIDTH = 60;
private static final int HEIGHT = 20; public void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("image/jpeg");
// 防止浏览器缓冲
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
HttpSession session = request.getSession();
BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
char[] rands = getCode();
drawBackground(g);
drawRands(g,rands);
g.dispose();
// 使用JPEGImageEncoder
// ServletOutputStream out = response.getOutputStream();
// JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
// encoder.encode(image);
// out.flush();
// 使用ImageIO
ServletOutputStream out = response.getOutputStream();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ImageIO.write(image, "JPEG", bos);
byte[] buf = bos.toByteArray();
response.setContentLength(buf.length);
out.write(buf); //bos.writeTo(sos);
bos.close();
out.close(); session.setAttribute("check", new String(rands));
}
/**
* 产生四位随机数
* @return
*/
private char[] getCode(){
String chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char[] rands = new char[4];
for(int i=0;i<rands.length;i++){
int rand = (int)(Math.random()*chars.length());
rands[i] = chars.charAt(rand);
}
return rands;
}
/**
* 绘制背景
* @param g
*/
private void drawBackground(Graphics g){
g.setColor(new Color(0xDCDCDC));
g.fillRect(0, 0, WIDTH, HEIGHT);
for(int i=0;i<60;i++){
int x = (int)(Math.random()*WIDTH);
int y = (int)(Math.random()*WIDTH);
int red = (int)(Math.random()*WIDTH);
int green = (int)(Math.random()*WIDTH);
int blue = (int)(Math.random()*WIDTH);
g.setColor(new Color(red,green,blue));
g.drawOval(x, y, 1, 0);
}
}
/**
* 绘制验证码
* @param g
* @param rands
*/
private void drawRands(Graphics g,char[] rands){
g.setColor(Color.black);
g.setFont(new Font("黑体",Font.ITALIC|Font.BOLD,18));
g.drawString(""+rands[0], 1, 17);
g.drawString(""+rands[1], 16, 15);
g.drawString(""+rands[2], 31, 18);
g.drawString(""+rands[3], 46, 16);
}
}