[分享]用Servlet产生验证码_Java Web开发

[分享]用Servlet产生验证码

package myproject;

import java.io.*;
import java.util.*;
import com.sun.image.codec.jpeg.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.awt.*;
import java.awt.image.*;

public class VerifyCode extends HttpServlet {

private Font mFont = new Font("Times New Roman", Font.PLAIN, 18); //设置字体

// 处理 Get 请求
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
//取得一个1000-9999的随机数

HttpSession session = request.getSession(false);
response.setContentType("image/gif");
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
int width = 60, height = 20;

ServletOutputStream out = response.getOutputStream();
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB); //设置图片大小的
Graphics graphics = image.getGraphics();
Random random = new Random();

graphics.setColor(getRandColor(200, 250)); //设置背景色
graphics.fillRect(0, 0, width, height);

graphics.setColor(Color.black); //设置字体色
graphics.setFont(mFont);

// 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
graphics.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);
graphics.drawLine(x, y, x + xl, y + yl);
}

// 取随机产生的认证码(4位数字)
String sRand = "";
for (int i = 0; i < 4; i++) {
String rand = String.valueOf(random.nextInt(10));
sRand += rand;
// 将认证码显示到图象中
graphics.setColor(new Color(20 + random.nextInt(110),
20 + random.nextInt(110),
20 + random.nextInt(110))); //调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
graphics.drawString(rand, 13 * i + 6, 16);
}
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(image);
out.close();

}

// 处理 Post 请求
public void doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
doGet(request, response);
}

static Color getRandColor(int fc, int bc) { //给定范围获得随机颜色
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);
}
}

[此贴子已经被作者于2007-7-8 1:56:58编辑过]

搜索更多相关主题的帖子: Servlet 验证分享

----------------解决方案--------------------------------------------------------

[CODE]
package myproject;

import java.io.*;
import java.util.*;
import com.sun.image.codec.jpeg.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.awt.*;
import java.awt.image.*;

public class VerifyCode extends HttpServlet {

private Font mFont = new Font("Times New Roman", Font.PLAIN, 18); //设置字体

// 处理 Get 请求
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
//取得一个1000-9999的随机数

graphics.setColor(getRandColor(200, 250)); //设置背景色
graphics.fillRect(0, 0, width, height);

graphics.setColor(Color.black); //设置字体色
graphics.setFont(mFont);

}

// 处理 Post 请求
public void doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
doGet(request, response);
}

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完全不知道LS两个在说什么
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这都看不出来,你功力太浅了！！
这就是传说中的贴代码比赛啊,20年才举行一次,你没听过吗？

----------------解决方案--------------------------------------------------------
真是太有意思了. 居然连20年1次的比赛都扯出来了
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^_^ 不好意思我对论坛不熟悉以前不玩这个我看到有人贴代码的时候用了”[CODE]“[ /CODE]“ 所以我想试试怎么用，有甚么效果”

[此贴子已经被作者于2007-7-8 17:29:42编辑过]

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谢谢大家支持

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我顶你个肺！！！
哈哈.........
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呵呵..
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