java中简单的验证码

package com.tsinghuait.beans;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.image.BufferedImage;

import java.io.FileNotFoundException;

import java.io.IOException;

import javax.imageio.ImageIO;

import javax.servlet.http.HttpServletResponse;

public class DrawImageBean {

public DrawImageBean() {

}

public String drawImage(HttpServletResponse response) {

String code = "";

BufferedImage image = new BufferedImage(64, 30, BufferedImage.TYPE_INT_RGB);//内存中的图片(宽, 高，颜色)

Graphics g = image.getGraphics();//得到画笔

//Add your code here and complete your image

g.setColor(Color.WHITE);//将颜色设置为白色

g.fillRect(0, 0, 400, 300);//填充整个区域

// g.setColor(new Color(100, 100, 100));

// g.drawString("Hello, world", 100, 100);

for(int i = 0; i< 100; i++) {//画出验证码干扰的线，防止识别软件读取进行恶意登录

g.setColor(new Color((int)(Math.random() * 256),

(int)(Math.random() * 256), (int)(Math.random() * 256)));//画笔的颜色

int x1 = 10 + (int)(Math.random() * 54);

int y1 = 30 - (int)(Math.random() * 30);

int x2 = x1 + 10;

int y2 = y1 + 10;

g.drawLine(x1, y1, x2, y2);//位置

}

for(int i = 0; i < 4; i++) {//画出验证码

g.setColor(new Color((int)(Math.random() * 80),

(int)(Math.random() * 80), (int)(Math.random() * 80)));//颜色较深，能看得清楚些

g.setFont(new Font("Times New Roman", Font.BOLD, 16));//字体

String s = String.valueOf((char)('A' + (int)(Math.random() * 58)));//生成验证码，范围是所有大写到所有小写，保存到字符串s

code += s;

g.drawString(s, 10 + i * 12, 15);

}

g.dispose();

try {

ImageIO.write(image, "JPEG", response.getOutputStream());//得到输出流，保存为jpg

}

catch (FileNotFoundException e) {

e.printStackTrace();

}

catch (IOException e) {

e.printStackTrace();

}

return code;

}

posted on 2009-10-24 10:17 Infernus 阅读(240) 评论(0) 编辑收藏

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