package rd.test;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//输出一张图片
public class Test1 extends HttpServlet {
public static final int WIDTH = 120;
public static final int HEIGHT = 35;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
//1,设置背景色
setBackGround(g);
//2，设置边框
setBorder(g);
//3，画干扰线
drowRandomLine(g);
//4，写随机数
//drawRandomNum(g);
String random = drawRandomNum2d((Graphics2D)g);//验证相关
request.getSession().setAttribute("checkcode",random);//验证相关
//5,图形写给浏览器
response.setContentType("image/jpeg");
//控制浏览器不要缓存随机验证码图片，让它每次都更新
response.setDateHeader("expries", -1);
response.setHeader("Cache-Control","no-cache");
response.setHeader("Pragma","no-cache");
ImageIO.write(image, "jpg", response.getOutputStream());
}
private void drowRandomLine(Graphics g) {
// TODO Auto-generated method stub
g.setColor(Color.GRAY);
for(int i = 0;i<5;i++) {
int x1 = new Random().nextInt(WIDTH-2)+2;
int y1 = new Random().nextInt(HEIGHT-2)+2;
int x2 = new Random().nextInt(WIDTH-2)+2;
int y2 = new Random().nextInt(HEIGHT-2)+2;
g.drawLine(x1, y1, x2, y2);
}
}
private String drawRandomNum2d(Graphics2D g) {
// TODO Auto-generated method stub
g.setColor(Color.RED);
g.setFont(new Font("宋体",Font.BOLD,20));
//[u4e00-u9fa5]
String base = "一二三四五六七八九十百千万兆亿啊我饿依无余";
StringBuffer sb = new StringBuffer();//验证相关
int x = 5;
for(int i = 0;i<4;i++) {
int degree = new Random().nextInt()%30;
String ch = "" + base.charAt(new Random().nextInt(base.length()));
sb.append(ch);//验证相关
g.rotate(degree*Math.PI/180, x, 25);//设置旋转幅度
g.drawString(ch, x, 25);
g.rotate(-degree*Math.PI/180, x, 25);//转回去
x+=30;
}
return sb.toString();
}
private void drawRandomNum(Graphics g) {
g.setColor(Color.RED);
g.setFont(new Font("宋体",Font.BOLD,20));
//[u4e00-u9fa5]
String base = "一二三四五六七八九十百千万兆亿啊我饿依无余";
int x = 5;
for(int i = 0;i<4;i++) {
String ch = "" + base.charAt(new Random().nextInt(base.length()));
g.drawString(ch, x, 20);
x+=30;
}
}
private void setBorder(Graphics g) {
g.setColor(Color.BLUE);
g.drawRect(1, 1, WIDTH-2, HEIGHT-2);
}
private void setBackGround(Graphics g) {
// TODO Auto-generated method stub
g.setColor(Color.WHITE);
g.fillRect(0, 0, WIDTH, HEIGHT);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
}
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <script type="text/javascript"> function changeImg(img){ img.src = img.src + "?" + new Date().getTime(); } </script> </head> <body> <form action="/web/servlet/check" method="post"> 用户名:<input type="text" name="username"> 密码 :<input type="password" name="password"><br/><br/> 验证码:<input type = "text" name="checkcode"> <img src="http://localhost:8080/random/servlet/Test1" onclick="changeImg(this)"/> <input type="submit" value="注册"> </form> </body> </html>
check:
request.setCharacterEncoding("UTF-8");
String c_checkcode = request.getParameter("checkcode");
String s_checkcode = request.getSession().getAttribut("checkcode");
if(c_checkcode!=null && s_checkcode!=null && c_checkcode.equals(s_checkcode)){
System.out.println("处理注册请求“);
}else{
System.out.println("验证码错误");
}