/***********************************servlet页面************************************/
package response;
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;
//产生随机图片（验证码）
public class ResponseDemo4 extends HttpServlet {
//定义图片的宽度
public static final int WIDTH = 120;
//定义图片的高度
public static final int HEIGHT= 30;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//在内存里面构建出一副图片
BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
//得到该图形
Graphics g = image.getGraphics();
//1，设置背景色
setBackGround(g);
//2，设置边框
setBorder(g);
//3，画干扰线
drawRandomLine(g);
//4，谢随机数
drawRandomNum((Graphics2D)g);
//5，图形写给浏览器
response.setContentType("image/jpeg");//通知浏览器以jpeg格式打开图片
//发头控制浏览器不要缓存
response.setDateHeader("expries", -1);
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", "no-cache");
ImageIO.write(image, "jpg", response.getOutputStream());
}
//填充汉字，Graphics没有旋转的操作，所以这里写成Graphics2D，但Graphics2D存在兼容性问题
private void drawRandomNum(Graphics2D g) {
//设置字体颜色
g.setColor(Color.RED);
//设置字体为宋体，粗体，大小20
g.setFont(new Font("宋体",Font.BOLD,20));
//汉字常用字
String base = "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";
int x = 5;//设置汉字出现的位置
for(int i = 0;i<4;i++){
//设置字的旋转弧度，不超过30度
// int degree = new Random().nextInt(30);//这样设计旋转只会在一个方向
//任意的随机数%30得到的数肯定比30小，这样也保证汉字的旋转弧度在-30～30之间
int degree = new Random().nextInt()%30;
//将得到的字符转换成字符串
String ch = base.charAt(new Random().nextInt(base.length()))+"";
//设置旋转角度
g.rotate(degree*Math.PI/180, x, 20);
//填充汉字
g.drawString(ch, x, 20);
//旋转完要将旋转操作恢复，以免影响下一次操作
g.rotate(-degree*Math.PI/180, x, 20);
x += 30; //设置下一个字的出现位置
}
}
private void drawRandomLine(Graphics g) {
//设置干扰线的颜色为绿色
g.setColor(Color.GREEN);
//画5条干扰线
for(int i = 0;i<5;i++){
//干扰线的起始坐标
int x1 = new Random().nextInt(WIDTH);
int y1 = new Random().nextInt(HEIGHT);
//干扰线的结束坐标
int x2 = new Random().nextInt(WIDTH);
int y2 = new Random().nextInt(HEIGHT);
//画干扰线
g.drawLine(x1, y1, x2, y2);
}
}
private void setBorder(Graphics g) {
//设置边框颜色为蓝色
g.setColor(Color.BLUE);
//填充(从0开始的话，边框画到外面去了)
g.drawRect(1, 1, WIDTH-2, HEIGHT-2);
}
private void setBackGround(Graphics g) {
//背景色设置为白色
g.setColor(Color.WHITE);
//填充矩形
g.fillRect(0, 0, WIDTH, HEIGHT);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
/************************************************注册页面*******************************************************/
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>用户注册</title>
<script type="text/javascript">
function changeImg(img){
img.src = img.src + "?" + new Date().getTime();
}
</script>
</head>
<body>
<form>
用户名：<input type="text" name="user"/><br/>
密码：<input type="password" name="pwd"/><br/>
验证码：<input type="text" name="check"/>
<!-- 实现点击图片验证码就换一张图片 -->
<img src="/requestandresponse/ResponseDemo4" onclick="changeImg(this)" alt="换一张" style="cursor: hand"><br/>
<input type="submit" value="提交">
</form>
</body>
</html>