复用性代码之验证码

package com.xupt508.checkCode.action;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.p_w_picpath.BufferedImage;

import java.util.Random;

import javax.p_w_picpathio.ImageIO;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class CheckImgAction extends ActionSupport {

@Override

public String execute() throws Exception {

int width = 120;

int height = 30;

// 步骤一 绘制一张内存中图片

BufferedImage bufferedImage = new BufferedImage(width, height,

BufferedImage.TYPE_INT_RGB);

// 步骤二 图片绘制背景颜色 ---经过绘图对象

Graphics graphics = bufferedImage.getGraphics();// 获得画图对象 --- 画笔

// 绘制任何图形以前 都必须指定一个颜色

graphics.setColor(getRandColor(200, 250));

graphics.fillRect(0, 0, width, height);

// 步骤三 绘制边框

graphics.setColor(Color.WHITE);

graphics.drawRect(0, 0, width - 1, height - 1);

// 步骤四 四个随机数字

Graphics2D graphics2d = (Graphics2D) graphics;

// 设置输出字体

graphics2d.setFont(new Font("宋体", Font.BOLD, 18));

String words ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";

Random random = new Random();// 生成随机数

// 定义StringBuffer 

StringBuffer sb = new StringBuffer();

// 定义x坐标

int x = 10;

for (int i = 0; i < 4; i++) {

// 随机颜色

graphics2d.setColor(new Color(20 + random.nextInt(110), 20 + random

.nextInt(110), 20 + random.nextInt(110)));

// 旋转 -30 --- 30度

int jiaodu = random.nextInt(60) - 30;

// 换算弧度

double theta = jiaodu * Math.PI / 180;

// 生成一个随机数字

int index = random.nextInt(words.length()); // 生成随机数 0 到 length - 1

// 得到字母数字

char c = words.charAt(index);

sb.append(c);

// 将c 输出到图片

graphics2d.rotate(theta, x, 20);

graphics2d.drawString(String.valueOf(c), x, 20);

graphics2d.rotate(-theta, x, 20);

x += 30;

}

// 将生成的字母存入到session中

ServletActionContext.getRequest().getSession().setAttribute("checkcode", sb.toString());

// 步骤五 绘制干扰线

graphics.setColor(getRandColor(160, 200));

int x1;

int x2;

int y1;

int y2;

for (int i = 0; i < 30; i++) {

x1 = random.nextInt(width);

x2 = random.nextInt(12);

y1 = random.nextInt(height);

y2 = random.nextInt(12);

graphics.drawLine(x1, y1, x1 + x2, x2 + y2);

}

// 将上面图片输出到浏览器 ImageIO

graphics.dispose();// 释放资源

ImageIO.write(bufferedImage, "jpg", ServletActionContext.getResponse().getOutputStream());

return NONE;

}

/**

* 取其某一范围的color

* 

* @param fc

*            int 范围参数1

* @param bc

*            int 范围参数2

* @return Color

*/

private Color getRandColor(int fc, int bc) {

// 取其随机颜色

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);

}

}